TY  - CONF
AU  - Amstutz, Ph.
AU  - Hellert, T.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Iterative Trajectory-Correction Scheme for the Early Commissioning of Diffraction-Limited Light Sources
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - The commissioning of diffraction-limited light sources will be significantly affected by the fact that typical lattice designs rely on very strong focussing elements in order to achieve the small emittance goals. Especially in the early-commissioning phase this can render procedures successfully used in the commissioning of existing third-generation light sources ill-suited for the application to these new machines. In this contribution we discuss an iterative approach to the early trajectory correction, based on the well-known pseudo-inversion of a trajectory-response matrix. Measuring this matrix during early commissioning can be cumbersome, so that an algorithm working with the model response matrix of the lattice is desirable. We discuss the stability of the iteration in the presence of lattice errors, resulting in differences between the actual and the model response matrix. Further, Tikhonov regularization is investigated as a means to trade off the RMS trajectory variation against the strength of the required corrector kicks.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 353
EP  - 356
KW  - MMI
KW  - lattice
KW  - feedback
KW  - simulation
KW  - storage-ring
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-MOPGW098
UR  - http://jacow.org/ipac2019/papers/mopgw098.pdf
ER  - 

TY  - CONF
AU  - Liu, C.
AU  - Bruno, D.
AU  - Marusic, A.
AU  - Minty, M.G.
AU  - Thieberger, P.
AU  - Wang, X.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Mitigation of Persistent Current Effects in the RHIC Superconducting Magnets
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - Persistent currents in superconducting magnet introduce errors in the magnetic fields especially at low operating currents. In addition, their decay cause magnetic field variations therefore drifts of beam orbits, tunes and chromaticities. To reduce field errors and suppress magnetic field variations, new magnetic cycles were proposed for low energy beam operation at RHIC. In the new magnetic cycles, the magnet current oscillates around the operating current with diminishing amplitude a few times before it settles. The new magnetic cycle has been demonstrated experimentally to reduce field errors and the amplitude of magnetic field variations significantly and is essential for the ongoing RHIC Beam Energy Scan II (BES-II) program. This article will present beam-based experimental studies of the persistent current effects with the new magnetic cycle, and discuss its application in RHIC and accelerators based on superconducting magnet in general.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 548
EP  - 551
KW  - dipole
KW  - quadrupole
KW  - sextupole
KW  - injection
KW  - betatron
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-MOPMP046
UR  - http://jacow.org/ipac2019/papers/mopmp046.pdf
ER  - 

TY  - CONF
AU  - Hao, Y.
AU  - Ptitsyn, V.
AU  - Qiang, J.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Electron Beam’s Closed Orbit in the Crab Crossing Scheme of Future Electron-Ion Colliders
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - In crab-crossing collision geometry the closed orbit of the electron beam will be altered by the beam-beam interaction and the tilted head and tail of the ion beam. We will present the linear model to determine the closed orbit and compare with the simulation. Also, the relation of the closed orbit and the synchro-betatron resonance will be presented.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 762
EP  - 765
KW  - electron
KW  - closed-orbit
KW  - luminosity
KW  - cavity
KW  - simulation
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-MOPRB081
UR  - http://jacow.org/ipac2019/papers/moprb081.pdf
ER  - 

TY  - CONF
AU  - Hao, Y.
AU  - Luo, Y.
AU  - Ptitsyn, V.
AU  - Qiang, J.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Scaling Properties of the Synchro-Beta Resonance in Crab Crossing Scheme of Future Electron Ion Collider
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - The synchro - beta resonance due to the beam-beam interaction was predicted by the strong-strong simulation in the future electron-ion collider designs. In this paper, we study the scaling properties of the degradation rate of this unwanted resonance. These studies motivated the possible countermeasures of the luminosity degradation associated with the resonance.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 766
EP  - 768
KW  - luminosity
KW  - resonance
KW  - electron
KW  - simulation
KW  - cavity
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-MOPRB082
UR  - http://jacow.org/ipac2019/papers/moprb082.pdf
ER  - 

TY  - CONF
AU  - Luo, Y.
AU  - Hao, Y.
AU  - Qiang, J.
AU  - Roblin, Y.
AU  - Willeke, F.J.
AU  - Zhang, H.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Simulation Challenges for eRHIC Beam-Beam Study
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - The 2015 Nuclear Science Advisory Committee Long Rang Plan identified the need for an electron-ion collider (EIC) facility as a gluon microscope with capabilities beyond those of any existing accelerator complex. To reach the required high energy, high luminosity, and high polarization, the eRHIC design, based on the existing heavy ion and polarized proton collider RHIC, adopts a very small \beta-function at the interaction points, a high collision repetition rate, and a novel hadron cooling scheme. A full crossing angle of 22 mrad and crab cavities for both electron and proton rings are required. In this article, we will present the high priority R\&D items related to the beam-beam interaction studies for the current eRHIC design, the simulation challenges, and our plans and methods to address them. Recent progresses on this project are reported too.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 785
EP  - 787
KW  - electron
KW  - proton
KW  - simulation
KW  - damping
KW  - emittance
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-MOPRB090
UR  - http://jacow.org/ipac2019/papers/moprb090.pdf
ER  - 

TY  - CONF
AU  - Luo, Y.
AU  - Bassi, G.
AU  - Blaskiewicz, M.
AU  - Fischer, W.
AU  - Hao, Y.
AU  - Montag, C.
AU  - Ohmi, K.
AU  - Ptitsyn, V.
AU  - Qiang, J.
AU  - Smaluk, V.V.
AU  - Willeke, F.J.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Combined Strong-Strong and Weak-Strong Beam-Beam Simulations for Crabbed Collision in eRHIC
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - In the eRHIC, to compensate the geometric luminosity loss, local crab cavities on both sides of the interaction points are to adopted. The previous strong-strong beam-beam simulations showed that the luminosity degradation depends on the crab cavity frequency, proton synchrotron tune, proton bunch length and so on. In this article, we apply a combined strong-strong and weak-strong beam-beam simulation to investigate the incoherent and coherent beam motions with crabbed collison, and to calculate more realistic beam emittance growth rates and luminosity degradation rate.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 788
EP  - 790
KW  - electron
KW  - proton
KW  - simulation
KW  - luminosity
KW  - cavity
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-MOPRB091
UR  - http://jacow.org/ipac2019/papers/moprb091.pdf
ER  - 

TY  - CONF
AU  - Qiang, J.
AU  - Brouwer, L.N.
AU  - Prestemon, S.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - A Phase Shifter for Multi-Pass Recirculating Proton LINAC
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - The multi-pass recirculating proton linac can significantly improve the usage efficiency of RF superconducting cavities by passing the proton beam through the same cavity multiple times. However, in order to achieve the multiple acceleration, synchronous conditions in phase have to be satisfied. In this paper, we propose a fixed field superconducting magnet system as a phase shifter to meet the synchronous conditions.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 802
EP  - 805
KW  - proton
KW  - cavity
KW  - linac
KW  - superconducting-magnet
KW  - superconducting-cavity
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-MOPRB103
UR  - http://jacow.org/ipac2019/papers/moprb103.pdf
ER  - 

TY  - CONF
AU  - Hellert, T.
AU  - Amstutz, Ph.
AU  - Steier, C.
AU  - Venturini, M.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - An Accelerator Toolbox (AT) Utility for Simulating the Commissioning of Storage-Rings
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - We present the development of an AT-based toolkit, which allows for realistic commissioning simulations of storage ring light sources by taking into account a multitude of error sources as well as diligently treating beam diagnostic limitations.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 1441
EP  - 1444
KW  - MMI
KW  - lattice
KW  - simulation
KW  - injection
KW  - alignment
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPGW021
UR  - http://jacow.org/ipac2019/papers/tupgw021.pdf
ER  - 

TY  - CONF
AU  - Hellert, T.
AU  - Amstutz, Ph.
AU  - Ehrlichman, M.P.
AU  - Leemann, S.C.
AU  - Steier, C.
AU  - Sun, C.
AU  - Venturini, M.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Commissioning Simulation Study for the Accumulator Ring of the Advanced Light Source Upgrade
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - The Advanced Light Source Upgrade (ALS-U) to a diffraction-limited soft x-rays light source requires the construction of an Accumulator Ring (AR) to enable swap-out, on-axis injection. The AR lattice is a Triple-Bend-Achromat lattice similar to that of the current ALS but to minimize the magnet sizes the vacuum chamber will be significantly narrower hence requiring a careful evaluation of the magnets’ field quality. This work presents the results of a detailed error tolerance study including a complete simulation of the commissioning process.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 1445
EP  - 1448
KW  - MMI
KW  - injection
KW  - lattice
KW  - quadrupole
KW  - simulation
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPGW022
UR  - http://jacow.org/ipac2019/papers/tupgw022.pdf
ER  - 

TY  - CONF
AU  - Leitner, D.
AU  - Casey, P.W.
AU  - Chow, K.
AU  - Fuller, D.F.
AU  - Leitner, M.
AU  - Lodge, A.J.
AU  - Lopez, M.
AU  - Niu, J.
AU  - Novak, P.
AU  - Steier, C.
AU  - Virostek, S.P.
AU  - Waldron, W.L.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Removal and Installation Planning for the Advanced Light Source - Upgrade Project
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - The ALS-U project is a proposed upgrade to the Advanced Light Source (ALS) at Berkeley Lab that aims to deliver diffraction limited performance in the soft x-ray range. By lowering the horizontal emittance to about 70 pm rad, the brightness for soft x-rays will increase two orders of magnitude compared to the current ALS. The design utilizes a nine-bend achromat lattice, with reverse bending magnets and on-axis swap-out injection utilizing an accumulator ring. This paper will describe the preliminary plans for the installation of the new three-bend achromat accumulator ring (AR) in the existing tunnel and for replacing the current storage ring with the new nine-bend achromat lattice. The AR will be installed during regular maintenance shutdowns while the ALS continues to operate. The SR will be replaced during a nine months installation period followed by three months of commissioning during the twelve darktime period.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 1609
EP  - 1611
KW  - storage-ring
KW  - MMI
KW  - injection
KW  - vacuum
KW  - shielding
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPGW088
UR  - http://jacow.org/ipac2019/papers/tupgw088.pdf
ER  - 

TY  - CONF
AU  - Sannibale, F.
AU  - Ehrlichman, M.P.
AU  - Hellert, T.
AU  - Leemann, S.C.
AU  - Robin, D.
AU  - Steier, C.
AU  - Sun, C.
AU  - Venturini, M.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Compensation of Insertion Device Induced Emittance Variations in Ultralow Emittance Storage Rings by a Dispersion Bump in a Wiggler
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - Multi-bend achromat lattices allow for the design of extremely low emittance electron storage rings and hence for the realization of extremely high- brightness X-ray photon sources. In these new rings, the beam energy lost to radiation in the insertion devices (IDs) is often comparable to that lost in the ring dipole magnets. This implies that with respect to the typical 3rd generation light source, these new machines are more sensitive to the energy loss variations randomly occurring as the many users independently operate the gap of their IDs. The consequent induced variations in radiation damping time, equilibrium emittance, and transverse beam sizes at the radiation point sources can be significant and degrade the experimental performance in some of the beam-lines. In this paper we describe and discuss a possible method to compensate for such emittance variations by using a variable dispersion bump localized inside a fixed gap wiggler.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 1627
EP  - 1630
KW  - emittance
KW  - wiggler
KW  - storage-ring
KW  - lattice
KW  - dipole
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPGW093
UR  - http://jacow.org/ipac2019/papers/tupgw093.pdf
ER  - 

TY  - CONF
AU  - Leemann, S.C.
AU  - Amstutz, Ph.
AU  - Ehrlichman, M.P.
AU  - Hellert, T.
AU  - Hexemer, A.
AU  - Liu, S.
AU  - Marcus, M.
AU  - Melton, C.N.
AU  - Nishimura, H.
AU  - Penn, G.
AU  - Sannibale, F.
AU  - Shapiro, D.A.
AU  - Sun, C.
AU  - Ushizima, D.
AU  - Venturini, M.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - First Attempts at Applying Machine Learning to ALS Storage Ring Stabilization
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - The ALS storage ring operates multiple feedbacks and feed-forwards during user operations to ensure that various source properties such as beam position, beam angle, and beam size are maintained constant. Without these active corrections, strong perturbations of the electron beam would result from constantly varying ID gaps and phases. An important part of the ID gap/phase compensation requires recording feed-forward tables. While recording such tables takes a lot of time during dedicated machine shifts, the resulting compensation data is imperfect due to machine drift both during and after recording of the table. Since it is impractical to repeat recording feed-forward tables on a more frequent basis, we have decided to employ Machine Learning techniques to improve ID compensation in order to stabilize electron beam properties at the source points.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 1631
EP  - 1634
KW  - experiment
KW  - quadrupole
KW  - storage-ring
KW  - operation
KW  - emittance
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPGW094
UR  - http://jacow.org/ipac2019/papers/tupgw094.pdf
ER  - 

TY  - CONF
AU  - Leemann, S.C.
AU  - Aiba, M.
AU  - Bengtsson, J.
AU  - Dallin, L.O.
AU  - Sannibale, F.
AU  - Streun, A.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Progress on a Novel 7BA Lattice for a 196-m Circumference Diffraction-Limited Soft X-Ray Storage Ring
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - The ALS Upgrade to a diffraction-limited soft x-ray storage ring calls for ultralow emittance in a very limited circumference. In this paper we report on progress with a lattice based on a 7BA with distributed chromatic correction. This lattice relies heavily on longitudinal gradient bends and reverse bending in order to suppress the emittance, so that, despite having only seven bends, ultralow emittance can be achieved in addition to large dynamic aperture and momentum acceptance. An initial alternate 7BA lattice has been revised to relax magnet requirements as well as further increase off-energy performance and resilience to machine imperfections. We now demonstrate ±2.5 mm dynamic aperture including errors and calculate the effect of IBS to show that this lattice achieves 6 hours Touschek lifetime (at 500 mA, including errors) and a brightness of roughly 3x10²¹ ph/s/mm²/mrad²/0.1%BW at 1 keV.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 1635
EP  - 1638
KW  - lattice
KW  - emittance
KW  - sextupole
KW  - optics
KW  - storage-ring
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPGW095
UR  - http://jacow.org/ipac2019/papers/tupgw095.pdf
ER  - 

TY  - CONF
AU  - Steier, C.
AU  - Amstutz, Ph.
AU  - Baptiste, K.M.
AU  - Bong, P.A.
AU  - Buice, E.S.
AU  - Casey, P.W.
AU  - Chow, K.
AU  - De Santis, S.
AU  - Donahue, R.J.
AU  - Ehrlichman, M.P.
AU  - Harkins, J.P.
AU  - Hellert, T.
AU  - Johnson, M.J.
AU  - Jung, J.-Y.
AU  - Leemann, S.C.
AU  - Leftwich-Vann, R.M.
AU  - Leitner, D.
AU  - Luo, T.H.
AU  - Omolayo, O.
AU  - Osborn, J.R.
AU  - Penn, G.
AU  - Portmann, G.J.
AU  - Robin, D.
AU  - Sannibale, F.
AU  - Sun, C.
AU  - Swenson, C.A.
AU  - Venturini, M.
AU  - Virostek, S.P.
AU  - Waldron, W.L.
AU  - Wallén, E.J.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Design Progress of ALS-U, the Soft X-ray Diffraction Limited Upgrade of the Advanced Light Source
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - The ALS-U project to upgrade the Advanced Light Source to a multi bend achromat lattice received CD-1 approval in 2018 marking the end of its conceptual design phase. The ALS-U design promises to deliver diffraction limited performance in the soft x-ray range by lowering the horizontal emittance to about 70 pm rad resulting in two orders of magnitude brightness increase for soft x-rays compared to the current ALS. The design utilizes a nine bend achromat lattice, with reverse bending magnets and on-axis swap-out injection utilizing an accumulator ring. This paper presents recent design progress of the accelerator, as well as new results of the mature R&D program.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 1639
EP  - 1642
KW  - emittance
KW  - lattice
KW  - cavity
KW  - storage-ring
KW  - vacuum
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPGW097
UR  - http://jacow.org/ipac2019/papers/tupgw097.pdf
ER  - 

TY  - CONF
AU  - Li, D.
AU  - Feng, H.Q.
AU  - Filippetto, D.
AU  - Johnson, M.J.
AU  - Lambert, A.R.
AU  - Luo, T.H.
AU  - Mitchell, C.E.
AU  - Qiang, J.
AU  - Sannibale, F.
AU  - Staples, J.W.
AU  - Virostek, S.P.
AU  - Wells, R.P.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Recent Progress on the Design of Normal Conducting APEX-II VHF CW Electron Gun
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - We report recent progress on the design of a normal conducting CW electron gun, APEX-II (Advanced Photo-injector EXperiment-II) at Lawrence Berkeley National Laboratory. APEX-II is an upgrade of the successful APEX gun and the LCLS-II (Linac Coherent Light Source-II) injector, aiming at applications for Free electron laser (FEL) such as LCLS-II High Energy upgrade, UED (Ultrafast Electron Diffraction) and UEM (Ultrafast Electron Microscopy). The APEX-II adopted a two-cell cavity design with resonant frequency of 162.5 MHz. The APEX-II gun is targeting to achieve exceeding 30 MV/m of launch gradient at the cathode and output energy above 1.5 MeV with transverse emittance of 0.1 um at 100 pC. Advanced MOGA optimization technique has been used for both the RF cavity design and extensive beam dynamics studies using APEX-like and LCLS-II like injector layout. Detailed RF designs, beam dynamics studies, preliminary engineering design and FEA analysis will be presented, with cavity features that were demonstrated to be crucial in the operation of the APEX gun.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 1891
EP  - 1894
KW  - cavity
KW  - gun
KW  - electron
KW  - cathode
KW  - brightness
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPRB097
UR  - http://jacow.org/ipac2019/papers/tuprb097.pdf
ER  - 

TY  - CONF
AU  - Huang, P.W.
AU  - Chen, Y.
AU  - Filippetto, D.
AU  - Good, J.D.
AU  - Groß, M.
AU  - Isaev, I.I.
AU  - Koschitzki, C.
AU  - Krasilnikov, M.
AU  - Lal, S.
AU  - Li, X.
AU  - Lishilin, O.
AU  - Melkumyan, D.
AU  - Niemczyk, R.
AU  - Oppelt, A.
AU  - Qian, H.J.
AU  - Sannibale, F.
AU  - Shaker, H.
AU  - Stephan, F.
AU  - Tang, C.-X.
AU  - Vashchenko, G.
AU  - Wan, W.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - SINGLE SHOT CATHODE TRANSVERSE MOMENTUM IMAGING IN PHOTOINJECTORS
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - In state of the art photoinjector electron sources, cathode performance determines the lower limit of achievable beam emittance. Measuring the thermal emittance at the photocathodes in electron guns is of vital importance for improving the injectors. Traditional methods, like solenoid scan, pepper-pot, need multi-shots and are time-consuming, therefore suffer from machine stability. Here we propose a new method, named cathode transverse momentum imaging. By tuning the gun solenoid focusing, the electrons’ transverse momentum at the cathode is imaged to a downstream screen, which enables a single shot measurement. Several experiments have been done at the Photo Injector Test Facility at DESY in Zeuthen (PITZ) with a Cs2Te cathode. Measurements of cathode transverse momentum, the corresponding spectra, cathode transverse momentum map and its correlation with surface electric field are presented.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 1964
EP  - 1967
KW  - cathode
KW  - solenoid
KW  - emittance
KW  - electron
KW  - simulation
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPTS014
UR  - http://jacow.org/ipac2019/papers/tupts014.pdf
ER  - 

TY  - CONF
AU  - Luo, T.H.
AU  - Feng, H.Q.
AU  - Filippetto, D.
AU  - Johnson, M.J.
AU  - Lambert, A.R.
AU  - Li, D.
AU  - Mitchell, C.E.
AU  - Sannibale, F.
AU  - Staples, J.W.
AU  - Virostek, S.P.
AU  - Wells, R.P.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - RF Design of APEX2 Cavities
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - APEX2 is a proposed high repetition rate, high brightness electron source based on CW normal conducting RF cavities, aiming to further extend the brightness performance for FEL and UED/UEM beyond APEX. APEX2 consists of two cavities, one gun cavity for generating photo-electrons and one following cavity for beam energy boosting. In this paper, we present the RF design of the APEX2 cavities. The design has considered both beam dynamics requirements and engineering feasibility. A novel geometry optimization method with Genetic Algorithm has been implemented in the design procedure.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 2094
EP  - 2097
KW  - gun
KW  - cavity
KW  - cathode
KW  - electron
KW  - brightness
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPTS076
UR  - http://jacow.org/ipac2019/papers/tupts076.pdf
ER  - 

TY  - CONF
AU  - Mitchell, C.E.
AU  - Feng, H.Q.
AU  - Filippetto, D.
AU  - Johnson, M.J.
AU  - Lambert, A.R.
AU  - Li, D.
AU  - Luo, T.H.
AU  - Sannibale, F.
AU  - Staples, J.W.
AU  - Virostek, S.P.
AU  - Wells, R.P.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Beam Dynamics Studies of an APEX2-Based Photoinjector
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - APEX2 is a proposed normal conducting radio-frequency (RF) electron gun operating in the very high frequency (VHF) range in continuous wave (CW) mode, designed to drive applications that require both high beam brightness and high repetition rate, such as free electron lasers (such as LCLS-II-HE), ultra-fast electron diffraction, and microscopy. The gun consists of a two-cell RF cavity operating at 162.5 MHz with a cathode field of 34 MV/m, together with an embedded focusing solenoid. We study the beam dynamics in an APEX-II-based photoinjector (up to ~20 MeV), targeting a transverse 95% beam emittance of 0.1 um at 12.5 A peak current for the case of 100 pC charge for FEL applications. The high cathode field leads to enhanced beam brightness, while the increased gun exit energy of ~1.5 MeV reduces the effects of space charge, and possibly eliminates the need for an RF buncher. The embedded solenoid is designed to control the transverse beam size while minimizing emittance growth due to geometric aberrations. As a result, the transverse beam performance targets are achieved, and ongoing work will further optimize longitudinal beam quality for downstream FEL transport.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 2109
EP  - 2112
KW  - solenoid
KW  - gun
KW  - emittance
KW  - cathode
KW  - focusing
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPTS080
UR  - http://jacow.org/ipac2019/papers/tupts080.pdf
ER  - 

TY  - CONF
AU  - Zhou, F.
AU  - Adolphsen, C.
AU  - Benwell, A.L.
AU  - Brown, G.W.
AU  - Colocho, W.S.
AU  - Ding, Y.
AU  - Dunning, M.P.
AU  - Grouev, K.
AU  - Huang, G.
AU  - Jacobson, B.T.
AU  - Liu, X.
AU  - Maxwell, T.J.
AU  - Sannibale, F.
AU  - Schmerge, J.F.
AU  - Smith, T.J.
AU  - Vecchione, T.
AU  - Wang, F.Y.
AU  - Zimmer, C.M.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - First Commissioning of LCLS-II CW Injector Source
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - The LCLS-II injector source includes a 186MHz CW rf-gun, a 1.3 GHz CW rf-buncher, a loadlock system for photocathode change, two main solenoids, and a few essential diagnostics. The electron beam is designed to operate at a high repetition rate, up to 1-MHz. Since summer of 2018 we started LCLS-II injector source commissioning immediately after the major installation was completed. Initial commissioning showed the rf-gun was severely contaminated with hydrocarbons and very limited power <600W could be fed into the gun cavity. After a few significant processes, we eventually removed the hydrocarbons and successfully delivered desired rf power of 80 kW to the gun. This paper reports first com-missioning results including gun bakeout and vacuum processing, CW RF-gun and buncher operation with nom-inal power, and measurements of rf stability and dark current.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 2171
EP  - 2173
KW  - gun
KW  - cavity
KW  - operation
KW  - electron
KW  - vacuum
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPTS106
UR  - http://jacow.org/ipac2019/papers/tupts106.pdf
ER  - 

TY  - CONF
AU  - Leitner, D.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - High Performance ECR Sources for Next-Generation Nuclear Science Facilities
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - Modern heavy-ion accelerators require intense heavy-ion beams with high charge state. Electron Cyclotron Resonance (ECR) sources are the primary tool for generating such beams. Advances in magnet technology and an improved understanding of the ECR ion source plasma physics have led to significant improvements in ECR source performance over the last several decades. The current state of the art is represented by third-generation sources operating at frequencies around 28 GHz and peak coil fields of about 7 T using NbTi conductor. Fourth-generation ECR ion sources with an operating frequency above 40 GHz have the potential to quadruple the source output beam current. These sources will need to incorporate advanced conductor technologies and/or novel coil configurations in order to exceed the limitations of the present structures. This talk will present worldwide efforts currently underway to develop high-performance ECR sources using new design approaches in support of next-generation nuclear physics facilities.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 2224
EP  - 2229
KW  - ECR
KW  - plasma
KW  - ion-source
KW  - ECRIS
KW  - electron
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-WEXPLS1
UR  - http://jacow.org/ipac2019/papers/wexpls1.pdf
ER  - 

TY  - CONF
AU  - Nghiem, P.A.P.
AU  - Alesini, D.
AU  - Aschikhin, A.
AU  - Audet, T.
AU  - Aßmann, R.W.
AU  - Beck, A.
AU  - Chancé, A.
AU  - Chen, M.
AU  - Chiadroni, E.
AU  - Cianchi, A.
AU  - Clarke, J.A.
AU  - Couprie, M.-E.
AU  - Croia, M.
AU  - Cros, B.
AU  - Dattoli, G.
AU  - Del Dotto, A.
AU  - Delerue, N.
AU  - Dorda, U.
AU  - Ferran Pousa, A.
AU  - Ferrario, M.
AU  - Fonseca, R.A.
AU  - Ghaith, A.
AU  - Giribono, A.
AU  - Gizzi, L.A.
AU  - Helm, A.
AU  - Hidding, B.
AU  - Hooker, S.M.
AU  - Ibison, M.G.
AU  - Jaroszynski, D.A.
AU  - Kruchinin, K.O.
AU  - Labate, L.
AU  - Lee, P.
AU  - Li, F.Y.
AU  - Li, X.
AU  - Libov, V.
AU  - Marchetti, B.
AU  - Martinez de la Ossa, A.
AU  - Marx, D.
AU  - Massimo, F.
AU  - Mathieu, F.
AU  - Maynard, G.
AU  - Mazzotta, Z.
AU  - Mehrling, T.J.
AU  - Molodozhentsev, A.Y.
AU  - Mosnier, A.
AU  - Mostacci, A.
AU  - Najmudin, Z.
AU  - Nguyen, F.
AU  - Niknejadi, P.
AU  - Oumbarek Espinos, D.
AU  - Pattathil, R.
AU  - Pompili, R.
AU  - Romeo, S.
AU  - Rossi, A.R.
AU  - Schaper, L.
AU  - Sheng, Z.M.
AU  - Shpakov, V.
AU  - Silva, L.O.
AU  - Silva, T.
AU  - Simon, C.
AU  - Specka, A.
AU  - Stella, A.
AU  - Streeter, M.J.V.
AU  - Svystun, E.N.
AU  - Symes, D.
AU  - Terzani, D.
AU  - Toci, G.
AU  - Tomassini, P.
AU  - Vaccarezza, C.
AU  - Vieira, J.M.
AU  - Vujanovic, M.
AU  - Walczak, R.
AU  - Walker, P.A.
AU  - Weikum, M.K.
AU  - Welsch, C.P.
AU  - Weng, S.M.
AU  - Wiggins, S.M.
AU  - Wolfenden, J.
AU  - Yoffe, S.
AU  - Zhu, J.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - EuPRAXIA, a Step Toward a Plasma-Wakefield Based Accelerator With High Beam Quality
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - The EuPRAXIA project aims at designing the world’s first accelerator based on plasma-wakefield advanced technique, which can deliver a 5 GeV electron beam with simultaneously high charge, low emittance and low energy spread to user’s communities. Such challenging objectives can only have a chance to be achieved when particular efforts are dedicated to identify the subsequent issues and to find the way to solve them. Many injection/acceleration schemes and techniques have been explored by means of thorough simulations in more than ten European institutes to sort out the most appropriate ones. The specific issues of high charge, high beam quality and beam extraction then transfer to the user’s applications, have been tackled with many innovative approaches*. This article highlights the different advanced methods that have been employed by the EuPRAXIA collaboration and the preliminary results obtained. The needs in terms of laser and plasma parameters for such an accelerator are also summarized.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 2291
EP  - 2295
KW  - plasma
KW  - laser
KW  - injection
KW  - acceleration
KW  - emittance
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-WEZZPLS2
UR  - http://jacow.org/ipac2019/papers/wezzpls2.pdf
ER  - 

TY  - CONF
AU  - Sun, C.
AU  - De Santis, S.
AU  - Filippetto, D.
AU  - Sannibale, F.
AU  - Steier, C.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Feasibility Study of Beam Profile Measurements Using Interferometer and Diffractometer Techniques for ALS-U
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - ALS-U is an ongoing upgrade of Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory. The upgraded ALS will replace the existing Triple-Bend Achromat (TBA) storage ring lattice with a compact Multi-Bend Achromat (MBA) lattice. This MBA technology allows us to tightly focus electron beams down to about 10 μm to reach diffraction limit in a soft x-ray region. The beam size measurement is a challenging task for this tightly focused beam. The interferometer technique with visible light from synchrotron radiation has been developed in many facilities to measure their beam size at a micrometer-level accuracy. In this paper, we will present the feasibility study of this technique for the ALS-U storage ring beam size measurement.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 2752
EP  - 2755
KW  - electron
KW  - synchrotron
KW  - storage-ring
KW  - radiation
KW  - lattice
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-WEPGW110
UR  - http://jacow.org/ipac2019/papers/wepgw110.pdf
ER  - 

TY  - CONF
AU  - Sun, C.
AU  - Amstutz, Ph.
AU  - Hellert, T.
AU  - Jung, J.-Y.
AU  - Leemann, S.C.
AU  - Osborn, J.R.
AU  - Placidi, M.
AU  - Steier, C.
AU  - Swenson, C.A.
AU  - Venturini, M.
AU  - Wan, W.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Design of Booster-to-Accumulator Transfer Line for Advanced Light Source Upgrade
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - For the Advanced Light Source Upgrade, an on-axis swap-out injection is applied to exchange bunch trains between the storage ring and the accumulator ring. To replenish the accumulator ring before the swap-out injection, an electron beam from Linac is first injected into the ALS booster to ramp up the energy, and then transported to the accumulator through the Booster-to-Accumulator (BTA) transfer line. The design of the BTA transfer line is a challenging task as it has to fit within a tight space while accommodating the booster and accumulator rings at different elevations. Moreover, the BTA design needs to meet the optics boundary conditions and ideally minimize the size requirements of vacuum-chamber apertures. In this paper, we will present a design option of the BTA transfer line, which meets both space limitations and beam physics requirements.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 2756
EP  - 2759
KW  - injection
KW  - quadrupole
KW  - storage-ring
KW  - optics
KW  - booster
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-WEPGW111
UR  - http://jacow.org/ipac2019/papers/wepgw111.pdf
ER  - 

TY  - CONF
AU  - Morozov, V.S.
AU  - Cai, Y.
AU  - Ent, R.
AU  - Furletova, Y.
AU  - Lin, F.
AU  - Michalski, T.J.
AU  - Nosochkov, Y.M.
AU  - Rajput-Ghoshal, R.
AU  - Sabbi, G.L.
AU  - Sullivan, M.K.
AU  - Wiseman, M.
AU  - Yoshida, R.
AU  - Zhang, Y.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Full Acceptance Interaction Region Design of JLEIC
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - Nuclear physics experiments envisioned at a proposed future Electron-Ion Collider (EIC) require high luminosity of 10³³-10³⁴ cm⁻²s⁻¹ and a full-acceptance detector capable of reconstruction of a whole electron-ion collision event. Due to a large asymmetry in the electron and ion momenta in an EIC, the particles associated with the initial ion tend to go at very small angles and have small rigidity offsets with respect to the initial ion beam. They are detected after they pass through the apertures of the final focusing quadrupoles. Therefore, the apertures must be sufficiently large to provide the acceptance required by experiments. In addition, to maximize the luminosity, the final focusing quadrupoles must be placed as close to the interaction point as possible. A combination of these requirements presents serious detection, optics and engineering design challenges. We present a design of a full-acceptance interaction region of Jefferson Lab Electron-Ion Collider (JLEIC). The paper presents how this design addresses the above requirements up to an ion momentum of 200 GeV/c. We summarize the magnet parameters, which are kept consistent with the Nb-Ti superconducting magnet technology.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 2787
EP  - 2790
KW  - electron
KW  - detector
KW  - dipole
KW  - coupling
KW  - interaction-region
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-WEPGW123
UR  - http://jacow.org/ipac2019/papers/wepgw123.pdf
ER  - 

TY  - CONF
AU  - Feng, H.Q.
AU  - Baptiste, K.M.
AU  - Huang, W.-H.
AU  - Li, D.
AU  - Liu, Z.N.
AU  - Luo, T.H.
AU  - Tang, C.-X.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Optimization of RF Cavities Using MOGA for ALS-U
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - A multi-objective genetic algorithm-based optimiza-tion process has been applied to optimize the RF design of a 500 MHz main cavity and a 1.5 GHz Higher Harmon-ic Cavity (HHC) for the Advanced Light Source upgrade (ALS-U) in Lawrence Berkeley National Laboratory (LBNL). For the main cavity, a significant improvement, compared with the existing ALS cavity, has been achieved in cavity shunt impedance and power loss den-sity simultaneously. The field strengths and distribution of the optimized structure are analysed for further re-search. For the HHC, a cavity with low R/Q has been pre-liminary designed to mitigate the beam instability. This study also serves as an example of how a genetic algo-rithm can be used for optimizing RF cavities.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 3007
EP  - 3010
KW  - cavity
KW  - impedance
KW  - simulation
KW  - controls
KW  - gun
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-WEPRB080
UR  - http://jacow.org/ipac2019/papers/weprb080.pdf
ER  - 

TY  - CONF
AU  - Feng, H.Q.
AU  - Baptiste, K.M.
AU  - De Santis, S.
AU  - Huang, W.-H.
AU  - Li, D.
AU  - Liu, Z.N.
AU  - Luo, T.H.
AU  - Tang, C.-X.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Design Study on Higher Harmonic Cavity for ALS-U
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - The ALS upgrade (ALS-U) to a diffraction-limited light source [1] depends on the ability to lengthen the stored bunches to limit the emittance growth and increase the beam life time. Higher harmonic cavities (HHCs), also known as Landau cavities, have been proposed to in-crease beam lifetime and Landau damping by lengthen-ing the bunch. We present an optimized 1.5 GHz normal conducting HHC design for the ALS-U with a supercon-ducting-like geometry using multi-objective genetic algorithm (MOGA) for lower R/Q. The optimization goal is to reach the required shunt impedance while maintain-ing a relatively high Q value of the cavities. To minimize the coupled bunch instabilities, higher-order mode (HOM) of the HHC as well as corresponding impedance are explored and characterized.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 3011
EP  - 3013
KW  - cavity
KW  - impedance
KW  - higher-order-mode
KW  - simulation
KW  - wakefield
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-WEPRB081
UR  - http://jacow.org/ipac2019/papers/weprb081.pdf
ER  - 

TY  - CONF
AU  - Lambert, A.R.
AU  - Feng, H.Q.
AU  - Filippetto, D.
AU  - Johnson, M.J.
AU  - Li, D.
AU  - Luo, T.H.
AU  - Mitchell, C.E.
AU  - Sannibale, F.
AU  - Staples, J.W.
AU  - Virostek, S.P.
AU  - Wells, R.P.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Mechanical Design and Analysis of the Proposed APEX2 VHF CW Electron Gun
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - Normal conducting radio-frequency (RF) guns resonating in the very high frequency (VHF) range (30-300 MHz) and operating in continuous wave (CW) mode have successfully achieved the targeted brightness and reliability necessary for upgrading the performance of current lower repetition rate accelerator-based instruments such as X-ray free electron lasers (FELs), and ultra-fast electron diffraction (UED) and microscopy (UEM). The APEX2 (Advanced Photo-injector Experiment 2) electron gun is a proposed upgrade for the current LCLS-II injector, which was based on the original APEX design. In contrast, APEX2 is designed as a two-cell cavity operating at 162.5 MHz with a launching field at the cathode equal to 34 MV/m, producing a beam energy of 1.5 to 2 MeV, more than double APEX. Operation of the gun in this condition will require upwards of 200 kW of RF power, thus proper thermal management is crucial to achieve target performance. This paper describes the current design, thermal performance and tuning methods.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 3014
EP  - 3016
KW  - cavity
KW  - gun
KW  - vacuum
KW  - electron
KW  - cathode
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-WEPRB084
UR  - http://jacow.org/ipac2019/papers/weprb084.pdf
ER  - 

TY  - CONF
AU  - Hwang, K.
AU  - Mitchell, C.E.
AU  - Ryne, R.D.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Chaos Indicators for Studying Dynamic Aperture in the IOTA Ring with Protons
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - The Integrable Optics Test Accelerator (IOTA) is a novel storage ring under commissioning at Fermi National Accelerator Laboratory designed (in part) to investigate the dynamics of beams in the presence of highly nonlinear transverse focusing fields that generate integrable single-particle motion. In this study, we explore the sensitivity of the lattice dynamic aperture to the presence of nonlinear space charge. For this purpose, two distinct chaos indicators are compared (frequency map analysis and forward-backward integration). Because the integrability of motion requires integer betatron tune advance between passes through the nonlinear magnetic element, a large role is played by space-charge-induced tune spread. As a result, these tools are also applied to a toy model of the IOTA lattice to investigate the sensitivity of dynamic aperture to violations of the integer tune advance condition.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 3301
EP  - 3303
KW  - space-charge
KW  - dynamic-aperture
KW  - lattice
KW  - simulation
KW  - betatron
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-WEPTS078
UR  - http://jacow.org/ipac2019/papers/wepts078.pdf
ER  - 

TY  - CONF
AU  - Mitchell, C.E.
AU  - Qiang, J.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Analysis of Particle Noise in a Gridless Spectral Poisson Solver for Symplectic Multiparticle Tracking
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - Gridless symplectic methods for self-consistent modeling of space charge in intense beams possess several advantages over traditional momentum-conserving particle-in-cell methods, including the absence of numerical grid heating and the presence of an underlying multi-particle Hamiltonian. Despite these advantages, there remains evidence of irreversible emittance growth due to numerical particle noise. For a class of such algorithms, a first-principles kinetic model of the numerical particle noise is obtained and applied to gain insight into noise-induced entropy growth and thermal relaxation.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 3304
EP  - 3306
KW  - space-charge
KW  - focusing
KW  - emittance
KW  - plasma
KW  - simulation
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-WEPTS079
UR  - http://jacow.org/ipac2019/papers/wepts079.pdf
ER  - 

TY  - CONF
AU  - Park, C.S.
AU  - Chattopadhyay, S.
AU  - Freemire, B.T.
AU  - Mitchell, C.E.
AU  - Ryne, R.D.
AU  - Stern, E.G.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Multipass Simulations of Space Charge Compensation using Electron Columns at IOTA
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - Defocusing repulsive forces due to self space charge fields lead to degradation of high-intensity particle beams. Being of particular concern for low- and medium-energy proton beams, they result in emittance growth, beam halo formation, and beam loss. They set stringent limits on the intensity of frontier accelerators; therefore, the mitigation of space charge effects is a crucial challenge to improve proton beam intensity. The space charge effects in a positively charged proton beam can be effectively compensated using negatively charged electron columns. In this paper, we present the results of simulations using Synergia of the Electron Column lattice for IOTA. Beam loss due to space charge effects and aperture restrictions have been studied, as well as bunch formation and matching using an adiabatic ramp of the RF cavity. The results show the need for space charge compensation, and provide the basis for integration of the Synergia and Warp codes in order to form a complete simulation of space charge compensation using an Electron Column in IOTA.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 3313
EP  - 3316
KW  - space-charge
KW  - electron
KW  - simulation
KW  - cavity
KW  - proton
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-WEPTS083
UR  - http://jacow.org/ipac2019/papers/wepts083.pdf
ER  - 

TY  - CONF
AU  - Qiang, J.
AU  - Bizzozero, D.A.
AU  - Ge, L.
AU  - Li, Z.
AU  - Ng, C.-K.
AU  - Xiao, L.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Integration of Cavity Design and Beam Dynamics Simulation Using the Parallel IMPACT and the ACE3P Codes
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - The 3D parallel code suite IMPACT has been extensively used in the beam dynamics study of photoinjectors while the 3D parallel code ACE3P has been extensively used in the RF cavity design. In this paper, we propose integrating the ACE3P cavity design and the IMPACT beam dynamics simulation into a single work flow. Such a workflow enables efficient simulation of 3D effects(e.g. RF coupler) on high performance computers.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 3317
EP  - 3320
KW  - cavity
KW  - simulation
KW  - emittance
KW  - electron
KW  - gun
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-WEPTS088
UR  - http://jacow.org/ipac2019/papers/wepts088.pdf
ER  - 

TY  - CONF
AU  - Qiang, J.
AU  - Li, B.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Microbunching Instability Mitigation via Multi-Stage Cancellation
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - The microbunching instability driven by beam collective effects in the linear accelerator of a free electron laser (FEL) facility can significantly degrade electron beam quality and FEL performance. Understanding and control of the instability is a priority for the design of modern high-brightness electron accelerators. In this paper, we study an instability cancellation phenomenon due to 180 degree phase slippage of the current modulations between different amplification stages. A case study of using a nonisochronous dogleg section in a double compression scheme to cancel the current modulation is illustrated.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 3321
EP  - 3324
KW  - bunching
KW  - electron
KW  - linac
KW  - laser
KW  - impedance
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-WEPTS089
UR  - http://jacow.org/ipac2019/papers/wepts089.pdf
ER  - 

TY  - CONF
AU  - Qiang, J.
AU  - Li, B.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Suppression of Microbunching Instability Through Dispersive Lattice
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - The microbunching instability from the initial small modulation such as shot-noise can be amplified by longitudinal space-charge force and causes significant electron beam quality degradation at the exit of accelerator for the next generation x-ray free electron laser. In the paper, we present analytical and numerical simulation studies of a novel method using dispersion leakage from some quadrupoles inside a chicane.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 3325
EP  - 3328
KW  - bunching
KW  - electron
KW  - linac
KW  - quadrupole
KW  - simulation
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-WEPTS090
UR  - http://jacow.org/ipac2019/papers/wepts090.pdf
ER  - 

TY  - CONF
AU  - Wu, J.
AU  - Qiang, J.
AU  - Raubenheimer, T.O.
AU  - Woodley, M.D.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Emittance Preservation for LCLS-II-HE Project
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - A small transverse slice emittance at the undulator entrance is essential for high performance of the free electron laser. To achieve this, preservation of the phase space density of the electron bunch during acceleration and compression is absolutely necessary. The LCLS-II-HE is designed to transport a 100 pC bunch with an emittance of ~0.3 mm-mrad with minimal emittance dilution. However, in simulations starting from a normalized emittance on the order of 0.1 mm-mrad, the emittance growth is significant. In this paper, the sources of emittance growth are studied along the accelerator, in particular, around the laser-heater, the two bunch compressors. We have investigated mechanisms of emittance growth such as space charge, coherent synchrotron radiation, chromatic aberration, and spurious dispersion. Due to the extremely small emittance from the injector, 3-D space charge effect is important to determine the space charge dominated region and emittance dominated region. With this understanding, emittance preservation schemes are proposed. Studies are carried out with IMPACT simulation code, as well as ASTRA and ELEGANT.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 3333
EP  - 3336
KW  - emittance
KW  - electron
KW  - lattice
KW  - laser
KW  - space-charge
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-WEPTS093
UR  - http://jacow.org/ipac2019/papers/wepts093.pdf
ER  - 

TY  - CONF
AU  - Leitner, M.
AU  - Arbelaez, D.
AU  - Bassan, H.
AU  - Bruch, D.E.
AU  - Chen, C.W.
AU  - Corlett, J.N.
AU  - DeMello, A.J.
AU  - Garcia Fajardo, L.
AU  - Leitner, D.
AU  - Marks, S.
AU  - Martinez-Galarce, D.S.
AU  - McCombs, K.A.
AU  - Miller, T.
AU  - Munson, D.V.
AU  - Niu, J.
AU  - Nuhn, H.-D.
AU  - Ray, K.L.
AU  - Rowen, M.
AU  - Sadlier, D.A.
AU  - Schlueter, D.
AU  - Wallén, E.J.
AU  - Wolf, Z.R.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Development of the Vertically Polarizing Hard X-Ray Undulator Segments for the Linear Coherent Light Source Upgrade (LCLS-II) Project
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - The Linear Coherent Light Source II (LCLS-II) is a free electron laser facility currently in its final construction stage at Stanford Linear Accelerator Center. The project includes two variable-gap, hybrid-permanent-magnet undulator lines: A soft x-ray undulator line with 21 undulator segments optimized for a photon energy range from 0.2 keV to 1.3 keV and a hard x-ray undulator line with 32 undulator segments designed for a photon energy range from 1.0 keV to 25.0 keV. This paper focuses on the design, development, and performance of the hard x-ray undulator line which utilizes uniquely-developed, vertically-polarizing undulators. To fully compensate the magnetic force throughout the entire gap range these devices incorporate non-linear spring systems which permit the construction of relatively compact undulators. However, significant magnetic field repeatability challenges have been encountered during prototyping of this novel design. The paper describes the innovative design improvements that were implemented which lead to reaching the LCLS-II required performance. These final design solutions can also be advantageous improving the operation of any future undulator design.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 3408
EP  - 3413
KW  - undulator
KW  - photon
KW  - operation
KW  - free-electron-laser
KW  - electron
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-THYPLM1
UR  - http://jacow.org/ipac2019/papers/thyplm1.pdf
ER  - 

TY  - CONF
AU  - Edelen, J.P.
AU  - Cook, N.M.
AU  - Hall, C.C.
AU  - Hu, Y.
AU  - Vay, J.-L.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Advanced Modeling and Optimization of Thermionic Energy Converters
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - Thermionic energy converters (TEC) are a class of thermoelectric devices, which promise improvements to the efficiency and cost of both small- and large-scale electricity generation. A TEC is comprised of a narrowly-separated thermionic emitter and an anode. Simple structures are often space-charge limited as operating temperatures produce currents exceeding the Child-Langmuir limit. We present results from 3D simulations of these devices using the particle-in-cell code Warp, developed at Lawrence Berkeley National Lab. We demonstrate improvements to the Warp code permitting high fidelity simulations of complex device geometries. These improvements include modeling of non-conformal geometries using mesh refinement and cut-cells with a dielectric solver, in addition to importing geometries directly from standard CAD output. In this paper we showcase some of these new features and demonstrate their use.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 3552
EP  - 3554
KW  - interface
KW  - simulation
KW  - cathode
KW  - framework
KW  - diagnostics
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-THPMP047
UR  - http://jacow.org/ipac2019/papers/thpmp047.pdf
ER  - 

TY  - CONF
AU  - Lishilin, O.
AU  - Brinkmann, R.
AU  - Chen, Y.
AU  - Good, J.D.
AU  - Groß, M.
AU  - Grüner, F.J.
AU  - Isaev, I.I.
AU  - Koschitzki, C.
AU  - Krasilnikov, M.
AU  - Loisch, G.
AU  - Martinez de la Ossa, A.
AU  - Mehrling, T.J.
AU  - Melkumyan, D.
AU  - Niemczyk, R.
AU  - Oppelt, A.
AU  - Osterhoff, J.
AU  - Qian, H.J.
AU  - Schroeder, C.B.
AU  - Stephan, F.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Overview and Prospects of Plasma Wakefield Acceleration Experiments at PITZ
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - The Photo Injector Test Facility at DESY in Zeuthen (PITZ) carries out studies of beam-driven plasma wakefield acceleration (PWFA). The facility possesses a flexible photocathode laser beam shaping system and a variety of diagnostics including a high-resolution dipole spectrometer and an rf deflector which enables the observation of the longitudinal phase space of electron beams after their passage through a plasma. Two plasma sources are available: a gas discharge plasma cell and a photoionized lithium vapor plasma cell. Studies at PITZ include investigations of the self-modulation instability of long electron beams and the high transformer ratio, i.e., the ratio between the maximum accelerating field behind the drive beam and the decelerating field within the beam. This overview includes the experimental results and plans for future experiments.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 3612
EP  - 3615
KW  - plasma
KW  - electron
KW  - wakefield
KW  - laser
KW  - experiment
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-THPGW016
UR  - http://jacow.org/ipac2019/papers/thpgw016.pdf
ER  - 

TY  - CONF
AU  - Lishilin, O.
AU  - Brinkmann, R.
AU  - Chen, Y.
AU  - Good, J.D.
AU  - Groß, M.
AU  - Grüner, F.J.
AU  - Isaev, I.I.
AU  - Koschitzki, C.
AU  - Krasilnikov, M.
AU  - Loisch, G.
AU  - Martinez de la Ossa, A.
AU  - Mehrling, T.J.
AU  - Oppelt, A.
AU  - Osterhoff, J.
AU  - Qian, H.J.
AU  - Schroeder, C.B.
AU  - Stephan, F.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Self-Modulation Instability of Electron Beams in Plasma Channels of Variable Length
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - The self-modulation instability (SMI) of long (in respect to the plasma wavelength) charged particle beams passing through plasma enables the use of currently existing high energy charged particle beams as drivers for plasma wakefield accelerators. At the Photo Injector Test facility at DESY in Zeuthen (PITZ) the SMI of electron beams is studied *, **. An enhanced experimental setup includes a plasma channel of variable length which allows to investigate in details the development stages of the SMI by measuring the instability growth rate and phase velocity as a function of propagation distance in the plasma. In this contribution we present the experimental setup improvements, first measurement results and supporting beam dynamics simulations.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 3616
EP  - 3618
KW  - plasma
KW  - wakefield
KW  - simulation
KW  - laser
KW  - electron
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-THPGW017
UR  - http://jacow.org/ipac2019/papers/thpgw017.pdf
ER  - 

TY  - CONF
AU  - Niknejadi, P.
AU  - D'Arcy, R.T.P.
AU  - Ferrario, M.
AU  - Garland, J.M.
AU  - Lindstrøm, C.A.
AU  - Mehrling, T.J.
AU  - Osterhoff, J.
AU  - Romeo, S.
AU  - Schaper, L.
AU  - Schmidt, B.
AU  - Tauscher, G.E.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - FLASHforward Findings for the EuPRAXIA Design Study and the Next-Generation of Compact Accelerator Facilities
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - FLASHForward, the exploratory FLASH beamline for Future-ORiented Wakefield Accelerator Research and Development, is a European pilot test bed facility for accelerating electron beams to GeV-levels in a few centimeters of ionized gas. The main focus is on the advancement of plasma-based particle acceleration technology through investigation of injection schemes, novel concepts and diagnostics, as well as benchmarking theoretical studies and simulations. Since the plasma wakefield will be driven by the optimal high-current-density electron beams extracted from the FLASH L-band Superconducting RF accelerator, FLASHForward has been in a unique position for studying and providing insight for the design study of next-generation light source and high energy physics facilities such as EuPRAXIA*. Summary of these findings and their broader impact is discussed here.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 3619
EP  - 3623
KW  - plasma
KW  - wakefield
KW  - focusing
KW  - electron
KW  - laser
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-THPGW019
UR  - http://jacow.org/ipac2019/papers/thpgw019.pdf
ER  - 

TY  - CONF
AU  - Weikum, M.K.
AU  - Akhter, T.
AU  - Alesini, D.
AU  - Alexandrova, A.S.
AU  - Anania, M.P.
AU  - Andreev, N.E.
AU  - Andriyash, I.A.
AU  - Aschikhin, A.
AU  - Audet, T.
AU  - Aßmann, R.W.
AU  - Bacci, A.
AU  - Barna, I.F.
AU  - Beaton, A.
AU  - Beck, A.
AU  - Beluze, A.
AU  - Bernhard, A.
AU  - Bielawski, S.
AU  - Bisesto, F.G.
AU  - Brandi, F.
AU  - Brinkmann, R.
AU  - Bründermann, E.
AU  - Bussmann, M.H.
AU  - Bussolino, G.
AU  - Büscher, M.
AU  - Chancé, A.
AU  - Chen, M.
AU  - Chiadroni, E.
AU  - Cianchi, A.
AU  - Clarke, J.A.
AU  - Cole, J.
AU  - Couprie, M.-E.
AU  - Croia, M.
AU  - Cros, B.
AU  - Crump, P.A.
AU  - Dattoli, G.
AU  - De Nicola, S.
AU  - Del Dotto, A.
AU  - Delerue, N.
AU  - Dias, J.M.
AU  - Dorda, U.
AU  - Fedele, R.
AU  - Ferran Pousa, A.
AU  - Ferrario, M.
AU  - Filippi, F.
AU  - Fiore, G.
AU  - Fonseca, R.A.
AU  - Galimberti, M.
AU  - Gallo, A.
AU  - Ghaith, A.
AU  - Giove, D.
AU  - Giribono, A.
AU  - Gizzi, L.A.
AU  - Grüner, F.J.
AU  - Habib, A.F.
AU  - Haefner, C.
AU  - Heinemann, T.
AU  - Hidding, B.
AU  - Holzer, B.J.
AU  - Hooker, S.M.
AU  - Hosokai, T.
AU  - Huebner, M.
AU  - Irman, A.
AU  - Jafarinia, F.
AU  - Jaroszynski, D.A.
AU  - Joshi, C.
AU  - Kaluza, M.
AU  - Kando, M.
AU  - Karger, O.S.
AU  - Karsch, S.
AU  - Khazanov, E.
AU  - Khikhlukha, D.
AU  - Knetsch, A.
AU  - Kocon, D.
AU  - Koester, P.
AU  - Kononenko, O.S.
AU  - Korn, G.
AU  - Kostyukov, I.
AU  - Kruchinin, K.O.
AU  - Labate, L.
AU  - Le Blanc, C.
AU  - Lechner, C.
AU  - Leemans, W.
AU  - Lehrach, A.
AU  - Li, X.
AU  - Libov, V.
AU  - Lifschitz, A.
AU  - Litvinenko, V.
AU  - Lu, W.
AU  - Lundh, O.
AU  - Maier, A.R.
AU  - Malka, V.
AU  - Manahan, G.G.
AU  - Mangles, S.P.D.
AU  - Marchetti, B.
AU  - Martinez de la Ossa, A.
AU  - Martins, J.L.
AU  - Mason, P.D.
AU  - Massimo, F.
AU  - Mathieu, F.
AU  - Maynard, G.
AU  - Mazzotta, Z.
AU  - Molodozhentsev, A.Y.
AU  - Mostacci, A.
AU  - Murphy, C.D.
AU  - Müller, A.-S.
AU  - Najmudin, Z.
AU  - Nghiem, P.A.P.
AU  - Nguyen, F.
AU  - Niknejadi, P.
AU  - Osterhoff, J.
AU  - Oumbarek Espinos, D.
AU  - Papadopoulos, D.N.
AU  - Patrizi, B.
AU  - Pattathil, R.
AU  - Petrillo, V.
AU  - Pocsai, M.A.
AU  - Poder, K.
AU  - Pompili, R.
AU  - Pribyl, L.
AU  - Pugacheva, D.
AU  - Romeo, S.
AU  - Rossetti Conti, M.
AU  - Rossi, A.R.
AU  - Rossmanith, R.
AU  - Roussel, E.
AU  - Sahai, A.A.
AU  - Sarri, G.
AU  - Schaper, L.
AU  - Scherkl, P.
AU  - Schramm, U.
AU  - Schroeder, C.B.
AU  - Scifo, J.
AU  - Serafini, L.
AU  - Sheng, Z.M.
AU  - Siders, C.
AU  - Silva, L.O.
AU  - Silva, T.
AU  - Simon, C.
AU  - Sinha, U.
AU  - Specka, A.
AU  - Streeter, M.J.V.
AU  - Svystun, E.N.
AU  - Symes, D.
AU  - Szwaj, C.
AU  - Tauscher, G.E.
AU  - Terzani, D.
AU  - Thompson, N.
AU  - Toci, G.
AU  - Tomassini, P.
AU  - Torres, R.
AU  - Ullmann, D.
AU  - Vaccarezza, C.
AU  - Vannini, M.
AU  - Vieira, J.M.
AU  - Villa, F.
AU  - Wahlstrom, C.-G.
AU  - Walczak, R.
AU  - Walker, P.A.
AU  - Wang, K.
AU  - Welsch, C.P.
AU  - Wiggins, S.M.
AU  - Wolfenden, J.
AU  - Xia, G.X.
AU  - Yabashi, M.
AU  - Zhu, J.
AU  - Zigler, A.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Status of the Horizon 2020 EuPRAXIA Conceptual Design Study
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - The Horizon 2020 Project EuPRAXIA (European Plasma Research Accelerator with eXcellence In Applications) is producing a conceptual design report for a highly compact and cost-effective European facility with multi-GeV electron beams accelerated using plasmas. EuPRAXIA will be set up as a distributed Open Innovation platform with two construction sites, one with a focus on beam-driven plasma acceleration (PWFA) and another site with a focus on laser-driven plasma acceleration (LWFA). User areas at both sites will provide access to FEL pilot experiments, positron generation and acceleration, compact radiation sources, and test beams for HEP detector development. Support centres in four different countries will complement the pan-European implementation of this infrastructure.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 3638
EP  - 3642
KW  - plasma
KW  - laser
KW  - electron
KW  - acceleration
KW  - site
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-THPGW026
UR  - http://jacow.org/ipac2019/papers/thpgw026.pdf
ER  - 

TY  - CONF
AU  - Lin, Z.Y.
AU  - Du, Y.-C.
AU  - Huang, G.
AU  - Huang, W.-H.
AU  - Sun, Z.
AU  - Tang, C.-X.
AU  - Tang, J.
AU  - Xu, Y.L.
AU  - Zhang, D.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - A Novel Microwave Switch-Based LLRF System for Long-Term System Phase Drift Calibration
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - The long-term phase drift is one of the important issue for the stability of the Low level RF system. The signal crosstalk and temperature effect on the RF field detectors will significantly limited the performance of the phase detecting precise and the phase locking. A novel micro-wave switch-based LLRF system has been developed in Tsinghua accelerator lab. The microwave switch are ap-plied to in the chopper circuit to turn continuous signal into pulse signal in the time domain to avoid the mutual signal interference. In this paper the LLRF system based on microwave switch is present. The preliminary long-term experiments result shows the phase stability can achieve about 50fs RMS slow drift; and the peak-to-peak value of the slow drift was (~2°C p-p) over 4 days.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 3915
EP  - 3917
KW  - LLRF
KW  - controls
KW  - coupling
KW  - ISOL
KW  - experiment
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-THPRB045
UR  - http://jacow.org/ipac2019/papers/thprb045.pdf
ER  - 

TY  - CONF
AU  - Lin, Z.Y.
AU  - Du, Y.-C.
AU  - Huang, G.
AU  - Huang, W.-H.
AU  - Sun, Z.
AU  - Tang, C.-X.
AU  - Tang, J.
AU  - Xu, Y.L.
AU  - Zhang, D.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - The Preliminary Long-Term Slow Drift Calibration Study in Low-Level Rf System
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - The phase drift of the RF signal in the low-level radio frequency (LLRF) system is observed in the long-term operation, which limits the performance and stability of the LLRF system. The long-term drift was reproduced in the lab. Its effect and sources of error were explored in the simple LLRF46 board and the simplest LLRF system. It is founded that the temperature will significantly lead to the phase distortion of the two signal channels, although with the same electron device. The distortion will finally cause the long-term drift with temperature floating. A fixed phase calibration signal (CAL signal) is applied to deal with the signal channels difference. The preliminary tests were conducted and the results were analysed.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 3918
EP  - 3920
KW  - LLRF
KW  - experiment
KW  - monitoring
KW  - timing
KW  - controls
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-THPRB046
UR  - http://jacow.org/ipac2019/papers/thprb046.pdf
ER  -