TY  - CONF
AU  - Li, W.
AU  - Bai, Z.H.
AU  - Wang, J.G.
AU  - Xu, D.R.
AU  - Zhao, Z.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Preliminary Study of Bunch Compression in the Hefei 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  - Short electron bunch has interesting applications in the synchrotron radiation light sources, such as the production of powerful coherent THz radiation, time resolving spectrum analysis, etc. In this work, we are interested in acquiring the short bunch in the storage ring with a small circumference like Hefei Light Source. In this paper, we tried to approach the short bunch in two separate methods: by increasing the higher harmonic cavity voltage and by reducing the momentum compaction factor. The preliminary result and observations are shown and discussed.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 151
EP  - 154
KW  - lattice
KW  - storage-ring
KW  - radiation
KW  - electron
KW  - synchrotron-radiation
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-MOPGW029
UR  - http://jacow.org/ipac2019/papers/mopgw029.pdf
ER  - 

TY  - CONF
AU  - Liu, G.
AU  - Bai, Z.H.
AU  - Li, W.
AU  - Wang, L.
AU  - Wang, P.N.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Off-Energy Off-Axis Injection with Pulsed Multipole Magnet Into the HALS 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  - As a future Diffraction-Limited Storage Ring (DLSR) at NSRL, the Hefei Advanced Light Source (HALS) has been proposed and has a great progress in the lattice optimization. The nonlinear dynamics is well designed and shows good performance, which makes it easier for beam injection and gives us more choices to design a more suitable injection scheme. In this paper, a new off-energy off-axis pulsed multipole injection scheme is proposed. The off-energy beam is off-axis injected into the acceptance of the storage ring with one or several pulsed multipole kickers and meanwhile the stored beam is almost unaffected during the injection. The injection acceptance of the storage ring is analyzed and the injection scheme is preliminary designed. A series of tracking simulations are carried out and the results are presented.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 187
EP  - 189
KW  - injection
KW  - storage-ring
KW  - kicker
KW  - lattice
KW  - multipole
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-MOPGW044
UR  - http://jacow.org/ipac2019/papers/mopgw044.pdf
ER  - 

TY  - CONF
AU  - Tan, J.J.
AU  - Bai, Z.H.
AU  - Li, W.
AU  - Wang, L.
AU  - Yang, P.H.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - A Fast Method for Multi-Objective Nonlinear Dynamics Optimization of a 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  - Multi-objective evolutionary algorithms (MOEAs), including multi-objective genetic algorithm and particle swarm optimization algorithm, have been widely applied in the nonlinear dynamics optimization of storage ring light sources. In the optimization, the direct tracking of objectives, which are, for example, dynamic aperture (DA) and momentum aperture, is very time-consuming. We noticed that there is some positive correlation between on- and off-momentum nonlinear dynamics performances, which can be used to reduce the computation time when applying MOEAs. In this paper, a fast method is proposed, in which a strategy is introduced to speed up the process of optimizing nonlinear dynamics using MOEAs. Taking the SSRF storage ring as an example, on- and off-momentum DAs are optimized using MOEAs with and without the fast strategy, and then a comparison is made to demonstrate the fast method.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 190
EP  - 192
KW  - SRF
KW  - storage-ring
KW  - lattice
KW  - sextupole
KW  - dynamic-aperture
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-MOPGW045
UR  - http://jacow.org/ipac2019/papers/mopgw045.pdf
ER  - 

TY  - CONF
AU  - Li, Y.
AU  - Bai, Z.H.
AU  - He, A.
AU  - Kosciuk, B.N.
AU  - Shaftan, T.V.
AU  - Smaluk, V.V.
AU  - Wang, L.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - A Cross-Cell Interleaved Nonlinear Lattice for Potential NSLS-II Upgrade
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - An interleaved sextupole scheme using cross-cell betatron phase cancellation technique is adopted as a candidate for the future NSLS-II upgrade lattice. The lattice uses as many NSLS-II installed magnets as possible, including 30 dipoles, to compose a triple bend achromat lattice. A 300 pm.rad horizontal beam emittance is achieved. The emittance can be further reduced to around 200 pm rad with damping wigglers. Various design concepts used in modern 4th-generation light sources, such as adopting longitudinal gradient dipoles and anti-bend scheme, are incorporated into the design as well. The betatron phase-advance between sextupoles is designed to have a cross-cell interleaving cancellation pattern in the transverse planes. The dynamic aperture is big enough for the conventional off-axis top-off injection. At the same time, a large energy acceptance looks promising to ensure a sufficiently long beam lifetime.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 393
EP  - 396
KW  - lattice
KW  - emittance
KW  - sextupole
KW  - optics
KW  - dynamic-aperture
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-MOPGW115
UR  - http://jacow.org/ipac2019/papers/mopgw115.pdf
ER  - 

TY  - CONF
AU  - Luo, Q.
AU  - Gao, W.W.
AU  - Lan, J.Q.
AU  - Li, W.
AU  - Xu, D.R.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Progress of Conceptual Study for the Accelerators of a 2-7GeV Super Tau Charm Facility at China
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - This paper shows the progress of the conceptual study for the accelerators of a super tau charm facility in China. Since the BEPCII will finish its historical mission in 5~10 years and its upgrade plan will only achieve a small luminosity enhancement of 3~5 times, a new next generation tau-charm collider will play an irreplaceable role in future high energy physics study. The luminosity of this successor is about 5×10³⁴cm^{−2}s^{−1} pilot and 1×10³⁵cm^{−2}s^{−1} nominal, with the electron beam longitudinally polarized at the IP. The general scheme of the accelerators and the beam pa-rameters are shown. Several key technologies such as beam polarization and beam emittance diagnostics are also discussed.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 643
EP  - 645
KW  - collider
KW  - luminosity
KW  - factory
KW  - electron
KW  - operation
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-MOPRB031
UR  - http://jacow.org/ipac2019/papers/moprb031.pdf
ER  - 

TY  - CONF
AU  - Gao, W.W.
AU  - Lan, J.Q.
AU  - Luo, Q.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Interaction Section Lattice Design for a STCF 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 Super Tau-Charm Factory (STCF) planning in China is characterized with high luminosity, wide energy range and high longitudinal polarized electron beam. In order to achieve high luminosity, this project will adopt the recently proposed collision scheme based on Large Piwinski angle and Crab Waist. In this paper, a preliminary lattice design of interaction region meeting the above collision scheme is described.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 646
EP  - 648
KW  - sextupole
KW  - betatron
KW  - interaction-region
KW  - quadrupole
KW  - luminosity
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-MOPRB032
UR  - http://jacow.org/ipac2019/papers/moprb032.pdf
ER  - 

TY  - CONF
AU  - Tang, Y.G.
AU  - Wang, L.
AU  - Wu, C.-F.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Preliminary Research of HOM for 100MHz Superconducting Cavity in the Pre-Research Project of HALS
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - A 100MHz QWR superconducting cavity is researched in the pre-research project of Hefei Advanced Light Source (HALS). Higher order modes (HOM) damping is a big challenge for synchrotron radiation light source. In this paper, we first apply the novel choke mode structure to the 100MHz QWR (quarter wave resonator) cavity in order to damp the HOM. We identify the main harmful higher order modes. The HOMs in the QWR cavity are suppressed by optimizing the choke dimensions. The broadband HOM impedance spectrum of the cavity was also evaluated by calculating the beam induced wake potential in time domain. The results show that choke mode structure has a good HOM damping effect on the QWR cavity.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 649
EP  - 651
KW  - HOM
KW  - cavity
KW  - impedance
KW  - damping
KW  - simulation
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-MOPRB033
UR  - http://jacow.org/ipac2019/papers/moprb033.pdf
ER  - 

TY  - CONF
AU  - Xu, D.R.
AU  - Xu, W.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Study on Beam-induced heating in injection section of Hefei 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  - Ceramic chambers distributed with metal belts on the inner surface are installed in the injection section at Hefei Light Source (HLS). Heating on the ceramics chambers has been observed during machine operation. An air compressor is used to cool these chambers due to concerns of overheating during top-up operation mode. To understand the sources of the heating, a series of experiments are performed with various beam currents and bunch filling patterns. The study shows that the heating is mainly caused by the narrow-band impedances of the ceramic chambers and their adjacent vacuum components.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 652
EP  - 655
KW  - impedance
KW  - vacuum
KW  - kicker
KW  - radiation
KW  - experiment
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-MOPRB036
UR  - http://jacow.org/ipac2019/papers/moprb036.pdf
ER  - 

TY  - CONF
AU  - Ge, X.Q.
AU  - Li, W.
AU  - Shao, J.Q.
AU  - Wang, S.
AU  - Wang, Y.
AU  - Wang, Y.G.
AU  - Wei, W.
AU  - Zhang, B.
AU  - Zhang, Y.X.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Comparison of TiZrV Non-evaporable Getter Films Deposited by DC Magnetron Sputtering or Quantitative Deposition
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - Ti-Zr-V non-evaporable getter (NEG) films have been widely used in vacuum chambers of various accelerators since their discovery. Recently, we have used a new method called ’quantitative deposition’ to deposit Ti-Zr-V NEG films on nichrome substrates. The surface morphology and surface chemical bonding information were collected by scanning electron microscopy. Although the film deposited by DC magnetron sputtering has more uniform grain growth, smoother grain boundaries and higher porosity, the two films all have porous network structure and can be used as getter films.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 1283
EP  - 1285
KW  - vacuum
KW  - site
KW  - target
KW  - interface
KW  - electron
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPMP021
UR  - http://jacow.org/ipac2019/papers/tupmp021.pdf
ER  - 

TY  - CONF
AU  - Shao, Z.X.
AU  - Gao, H.
AU  - Liu, G.
AU  - Liu, P.
AU  - Sun, X.K.
AU  - Zhang, H.Y.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Research and Design of Digital Magnet Power Supply Controller
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - Hefei Advanced Light Source (HALS) is the fourth-generation radiation light source in China which is under design. Ultra-low beam emittance requires higher performance of power supply system. The power supply controller is a key part of the power system. This article describes the design and testing of high-stability power controllers and fast corrector power supply controllers. A new controller architecture is proposed for the problems of the two controllers.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 1297
EP  - 1299
KW  - controls
KW  - power-supply
KW  - Ethernet
KW  - real-time
KW  - FPGA
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPMP027
UR  - http://jacow.org/ipac2019/papers/tupmp027.pdf
ER  - 

TY  - CONF
AU  - Shao, Z.X.
AU  - Gao, H.
AU  - Liu, G.
AU  - Liu, P.
AU  - Wang, L.
AU  - Zhang, H.Y.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Research Progress of Power Supply System in HALS
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - Hefei Advanced Light Source (HALS) is the fourth generation light source in China’s planning and construction. In order to achieve the diffraction limit of the emission and improve the beam quality, the research on magnet power supply (MPS) technology is essential. We have designed a variety of solutions for different power supplies. We designed the first version of the high stability power supply control card. The first version of the high-stability power supply control card was designed and tested with a small power module. Our pre-research system has developed a corrector magnet power supply with a small signal response bandwidth higher than 10 kHz. The developed power prototypes all use self-developed controllers, and most of the test results can meet the requirements. This article describes the progress of the HALS power supply system.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 1300
EP  - 1302
KW  - power-supply
KW  - controls
KW  - dipole
KW  - ISOL
KW  - interface
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPMP028
UR  - http://jacow.org/ipac2019/papers/tupmp028.pdf
ER  - 

TY  - CONF
AU  - Wang, Y.G.
AU  - Ge, X.Q.
AU  - Pei, X.T.
AU  - Wang, S.W.
AU  - Wang, Y.
AU  - Zhang, B.
AU  - Zhu, B.L.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Establishing a Laser Treatment to Suppress the Secondary Electron Emission
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - Laser treatment has a significant inluent on suppressing the secondary electron emission(SEE). The new synchrotron radiation light source, the Hefei Advanced Light Source(HALS) has a strict requirement on the SEE. In this paper, we used a 355nm laser to process copper sample. After the laser treatment, the secondary electron yield(SEY) reduced from 2.05 to 0.86. We used the scanning electron microscope(SEM) to analysis the surface of sample after the laser treatment.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 1303
EP  - 1305
KW  - laser
KW  - electron
KW  - experiment
KW  - synchrotron
KW  - focusing
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPMP029
UR  - http://jacow.org/ipac2019/papers/tupmp029.pdf
ER  - 

TY  - CONF
AU  - Zhang, Y.X.
AU  - Ge, X.Q.
AU  - Li, W.
AU  - Shao, J.Q.
AU  - Wang, S.
AU  - Wang, Y.
AU  - Wang, Y.G.
AU  - Wei, W.
AU  - Zhang, B.
AU  - Zhu, B.L.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Research on Secondary Electron Emission Characteristics of Diamond-like Carbon Thin Films
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - In modern particle accelerators, the build-up of electron cloud is a main limiting factor for the achievement of high-quality beam. Among the techniques to mitigate it, coating the internal walls of the beam pipes with a thin film which has a low secondary electron yield (SEY) is considered to be one of the most effective means. From several earlier studies, it was found that diamond-like carbon (DLC) thin films are potential coatings. This paper is mainly about the research on secondary electron emission characteristics of DLC thin films. The secondary electron emission (SEE) tests were done at temperature of 298 K and vacuum pressure of 2×10⁻⁹ Torr. Here, we obtained the characteristics of the SEE from DLC film coatings with different thickness under ultrahigh-vacuum (UHV) conditions. The maximum secondary electron yield (SEY), δmax, of the DLC thin films under different primary electron doses were also obtained, respectively.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 1306
EP  - 1308
KW  - electron
KW  - vacuum
KW  - experiment
KW  - laser
KW  - gun
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPMP031
UR  - http://jacow.org/ipac2019/papers/tupmp031.pdf
ER  - 

TY  - CONF
AU  - Xu, D.R.
AU  - Bai, Z.H.
AU  - Li, W.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Error Study and Correction of Hefei 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  - Hefei Advanced Light Source (HALS) is a future diffraction limited storage ring. The machine performance under all kinds of magnet errors is a vital component in physical design. In this paper, we present our work on the closed orbit correction, the linear beam optics compensation and the coupling control in HALS. After correction, the dynamical aperture can suffice the injection scheme.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 1492
EP  - 1494
KW  - lattice
KW  - optics
KW  - quadrupole
KW  - closed-orbit
KW  - coupling
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPGW039
UR  - http://jacow.org/ipac2019/papers/tupgw039.pdf
ER  - 

TY  - CONF
AU  - Bai, Z.H.
AU  - Li, W.
AU  - Liu, G.
AU  - Wang, L.
AU  - Xu, D.R.
AU  - Zhang, T.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Study of Seven-Bend Achromat Lattices with Interleaved Dispersion Bumps for HALS
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - Previously, we proposed a multi-bend achromat (MBA) lattice concept, called the MBA with interleav-ed dispersion bumps, which was then used to design a 7BA lattice for the Hefei Advanced Light Source (HALS) storage ring. Recently, such a 7BA lattice was further designed and optimized for the HALS by changing the number of lattice cells, scanning working point and employing octupoles. And two new HALS designs with such 7BA lattices have been made, one with 30 lattice cells and a natural emittance of 25 pm·rad and the other with 28 cells and 33 pm·rad. They had much better nonlinear dynamics perfor-mances than the previous design. The detailed study for these two HALS lattices will be presented in this paper.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 1495
EP  - 1497
KW  - lattice
KW  - storage-ring
KW  - emittance
KW  - octupole
KW  - linear-dynamics
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPGW040
UR  - http://jacow.org/ipac2019/papers/tupgw040.pdf
ER  - 

TY  - CONF
AU  - Bai, Z.H.
AU  - Li, W.
AU  - Li, Y.
AU  - Liu, G.
AU  - Wang, L.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Super-Period Locally Symmetric Lattices for Designing Diffraction-Limited 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  - To achieve better nonlinear dynamics performance for a diffraction-limited storage ring, previously we proposed a locally symmetric multi-bend-achromat (MBA) lattice concept, where beta functions are locally symmetric about two mirror planes of each lattice cell. To have both high-beta long straight sections for beam injection and low-beta ones for higher brightness of insertion device radiation, many storage ring light sources use super-period lattices. The locally symmetric MBA lattice can be naturally extended to the super-period case. In the super-period locally symmetric (SP-LS) lattice, many nonlinear dynamics effects can be effectively cancelled out within one super-period lattice cell, and also there are many knobs to be used for further nonlinear optimization. As examples, two SP-LS lattices have been designed towards diffraction-limited emittances.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 1498
EP  - 1500
KW  - lattice
KW  - storage-ring
KW  - emittance
KW  - sextupole
KW  - quadrupole
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPGW041
UR  - http://jacow.org/ipac2019/papers/tupgw041.pdf
ER  - 

TY  - CONF
AU  - Li, W.
AU  - Bai, Z.H.
AU  - Xu, D.R.
AU  - Zhang, T.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Study of the Intra-beam Scattering Effects in the HALS 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 Hefei Advanced Light Source (HALS) is designed to be a dedicated 4th generation diffraction limited light source. In 2018, the baseline lattice of the HALS storage ring has been proposed, with an ultra-low natural emittance of about 25 pm-rad. The preliminary study of intra-beam scattering effects on the beam emittance growth in the HALS storage ring has been performed with this baseline lattice. Due to the limited synchrotron radiation in this storage ring, damping wigglers are expected in this storage ring to reduce the damping time and reduce the emittance. In this paper, we will present the simulation results of the IBS effects, estimated effectiveness of damping wiggler and the corresponding linear optics calibration of the perturbation due to insertion device, and finally the estimated Touschek lifetime will be shown.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 1501
EP  - 1503
KW  - emittance
KW  - damping
KW  - wiggler
KW  - storage-ring
KW  - lattice
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPGW042
UR  - http://jacow.org/ipac2019/papers/tupgw042.pdf
ER  - 

TY  - CONF
AU  - Wang, W.X.
AU  - He, Z.G.
AU  - Jiang, S.M.
AU  - Zhang, H.R.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Generation of Two Terahertz Radiation Pulses with Continuously Tunable Frequency and Time Delay
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - We propose to generate two narrow band terahertz pulses radiated from two temporally modulated relativistic electron beams, which are generated in a photo-injector. The temporal profile of the drive laser is modulated by means of the paired chirped pulses beating technique, leading to the generation of two pre-bunched electron beams. Coherent transient radiation (CTR) is considered as the mechanism for terahertz radiation generation. The frequencies of the two terahertz pulses can be independently tuned by adjusting the paired beating frequencies, and the interval between the two terahertz pulses can be adjusted by the optical delay line.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 1518
EP  - 1520
KW  - electron
KW  - radiation
KW  - laser
KW  - cathode
KW  - gun
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPGW051
UR  - http://jacow.org/ipac2019/papers/tupgw051.pdf
ER  - 

TY  - CONF
AU  - Yang, P.H.
AU  - Bai, Z.H.
AU  - Tan, J.J.
AU  - Wang, L.
AU  - Xu, J.H.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Design of a Hybrid Seven-Bend-Achromat Lattice for a High-Energy Diffraction-Limited Storage Ring Using a New Optimization Method
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - Recently, we proposed a new optimization method, with nonlinear dynamics indicators considered in the linear optics design, for designing hybrid multi-bend-achromat (MBA) lattices. With this method, two hybrid MBA lattices for medium-low-energy diffraction limited storage rings (DLSRs) have been designed, showing remarkable effectiveness in improving nonlinear dynamic performance. In this paper, we will apply this optimization method to the design of a hybrid 7BA lattice for a 6 GeV DLSR with the same circumference as that of HEPS. In the design, the strengths and arrangement of magnets of this lattice also meet the engineering requirement for HEPS. The designed lattice has a natural emittance of 34 pm·rad. The nonlinear dynamic performance is satisfactory, with a dynamic aperture of about 6 mm and 3 mm in the horizontal and vertical directions, respectively, and a dynamic momentum aperture of larger than 5%, which also shows the power of our optimization method.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 1528
EP  - 1531
KW  - lattice
KW  - linear-dynamics
KW  - emittance
KW  - optics
KW  - sextupole
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPGW054
UR  - http://jacow.org/ipac2019/papers/tupgw054.pdf
ER  - 

TY  - CONF
AU  - Yang, P.H.
AU  - Bai, Z.H.
AU  - Tan, J.J.
AU  - Wang, L.
AU  - Xu, J.H.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Comparison of Optimization Methods for Hybrid Seven-Bend-Achromat Lattice Design
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - Generally, for a hybrid multi-bend-achromat (MBA) lattice with fixed linear optics, there is little potential to further optimize the nonlinear dynamics due to limited free knobs. To obtain a hybrid MBA lattice with better nonlinear dynamics performance, it is better to consider some indicators of nonlinear dynamics as objective functions in designing the linear optics using an optimization algorithm. In this paper, integral strengths of sextupoles and natural chromaticities are used as the nonlinear dynamics indicators, and different optimization methods with both or either of the two indicators are carried out and compared. As an example, a hybrid 7BA lattice with an energy of 2.4 GeV is designed towards an emittance of less than 70 pm·rad.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 1532
EP  - 1534
KW  - lattice
KW  - linear-dynamics
KW  - sextupole
KW  - optics
KW  - emittance
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPGW055
UR  - http://jacow.org/ipac2019/papers/tupgw055.pdf
ER  - 

TY  - CONF
AU  - Xu, J.H.
AU  - Bai, Z.H.
AU  - Li, W.
AU  - Yang, P.H.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Comparison of Constrained Optimization Methods for Designing a Multi-Bend Achromat Lattice
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 design of a multi-bend achromat (MBA) lattice for a diffraction-limited storage ring, there are usually many magnet parameters to be optimized and some stringent constraints to be satisfied. For example, to cancel out nonlinear dynamics effects, the phase advances between some sections are generally required to be set to certain values in the lattice design. For better designing a MBA lattice using an evolutionary algorithm, the handling of constraints will be important, because it is very hard to satisfy the constraints for most or even all of solutions in the early generations of the algorithm. This paper will first describe some methods for handling constraints, which are then applied to designing a hybrid 7BA lattice. The comparison of these methods shows that better lattice solutions can be obtained by including constraints into objective functions.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 1535
EP  - 1537
KW  - lattice
KW  - emittance
KW  - sextupole
KW  - storage-ring
KW  - linear-dynamics
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPGW056
UR  - http://jacow.org/ipac2019/papers/tupgw056.pdf
ER  - 

TY  - CONF
AU  - Yang, P.H.
AU  - Bai, Z.H.
AU  - Tan, J.J.
AU  - Wang, L.
AU  - Xu, J.H.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - A Ten-Bend Achromat Lattice with Interleaved Dispersion Bumps for a Diffraction-Limited 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  - Recently, a multi-bend achromat (MBA) lattice concept, called the MBA with interleaved dispersion bumps (IDB-MBA), was proposed to design the HALS storage ring, which presented better performance of both on- and off-momentum nonlinear dynamics. Since the beam emittance scales inversely with the third power of the number of bending magnets, in this paper we will study a new IDB-MBA lattice with more bending magnets. It is feasible to satisfy the requirement of the IDB-MBA concept in a 10BA lattice, and an IDB-10BA lattice is then designed for a storage ring light source with an energy of 2.4 GeV. The designed lattice has an ultra-low natural emittance of 81 pm·rad, and a dynamic aperture of about 6 mm and a large dynamic momentum aperture of 6% are achieved.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 1538
EP  - 1540
KW  - lattice
KW  - emittance
KW  - storage-ring
KW  - sextupole
KW  - quadrupole
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPGW057
UR  - http://jacow.org/ipac2019/papers/tupgw057.pdf
ER  - 

TY  - CONF
AU  - Dehler, M.M.
AU  - Alberti, S.
AU  - Citterio, A.
AU  - Hahn, M.
AU  - Hogge, J.P.
AU  - Liu, X.Y.
AU  - Marques, H.P.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Characterization of NEG Coatings for SLS 2.0
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - To limit desorption and ameliorate pumping of the narrow 20 mm aperture vacuum chamber of SLS2.0, it is planned to fully coat it with nonevaporable getter (NEG) material. NEG coating can be produced with different structural characteristics, from dense films to columnar growth, with corresponding distinct electrical properties affecting the machine impedance and the instability threshold of the accelerator. In order to evaluate and characterize the coating process for geometries similar to the SLS chamber, we measured the resonance properties of coated and uncoated shorted waveguide pieces. First tests were done with standard X band waveguides at 12 and 7 GHz. Test setups using elliptical cross sections are in preparation, also for higher frequencies allowing the characterization of thin NEG layers. The final goal is to have a standardized process to test of samples coated by external producers. We describe the setups and first results.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 1662
EP  - 1665
KW  - GUI
KW  - impedance
KW  - resonance
KW  - coupling
KW  - vacuum
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPGW108
UR  - http://jacow.org/ipac2019/papers/tupgw108.pdf
ER  - 

TY  - CONF
AU  - Jiang, S.M.
AU  - He, D.
AU  - He, Z.G.
AU  - Jia, Q.K.
AU  - Li, W.W.
AU  - Wang, L.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Stimulated Excitation by Seeding With Cherenkov Radiation in an Optical Cavity
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - By seeding with narrow-band Cherenkov radiation from a dielectric loaded waveguide(DLW), stimulated excitation in an optical cavity is presented. The evolution and energy loss of the field oscillating in optical cavity is analysed by the theoretical and numerical calculation. The results show that the high order TM modes of the Cherenkov radiation can be better preserved after a large number of roundtrips in the optical cavity and this scheme offers a potential method of realizing high power Terahertz radiation source in a compact facility.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 1785
EP  - 1787
KW  - radiation
KW  - cavity
KW  - electron
KW  - GUI
KW  - ion-source
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPRB045
UR  - http://jacow.org/ipac2019/papers/tuprb045.pdf
ER  - 

TY  - CONF
AU  - Zhang, H.R.
AU  - He, Z.G.
AU  - Jiang, S.M.
AU  - Wang, W.X.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - THz-Pump and UV-Probe Scheme Based on 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  - We propose a THz-pump and UV-probe scheme based on storage ring for ultra-fast dynamics experiment. In which, two sequential laser pulses, one of which has a periodic intensity envelope, simultaneously interact with different parts of the long electron beam in a modulator; after a chicane, the part that interacts with the periodic pulse will bunch at THz domain and radiate through a bend magnet, another based on high-harmonic generation will bunch at UV domain and radiate at a radiator. The electron beam can be utilized circularly in the storage ring, which will increase its average power. The feasibility of this THz-pump and UV-probe scheme is verified in both theory and simulation.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 1811
EP  - 1813
KW  - laser
KW  - electron
KW  - radiation
KW  - bunching
KW  - storage-ring
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPRB057
UR  - http://jacow.org/ipac2019/papers/tuprb057.pdf
ER  - 

TY  - CONF
AU  - Zhao, Z.
AU  - Jia, Q.K.
AU  - Li, H.T.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Seeded Free-Electron Lasers Driven by a Transverse Tilted Electron Bunch
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - A transverse tilt of the electron bunch is normally unwanted in free-electron laser (FEL) since only a portion of the bunch can contribute to the FEL radiation. However, the recent researches demonstrate that the tilted bunch can be used to generate FEL with some special features. In this work we investigate the generation of a large tilt of the bunch by using a corrugated structure and a dogleg separately. Based on the tilted bunch, the creation of ultra-short pulse and multi-color pulses are demonstrated in high-gain harmonic generation (HGHG) FEL.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 1817
EP  - 1819
KW  - laser
KW  - FEL
KW  - electron
KW  - undulator
KW  - radiation
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPRB061
UR  - http://jacow.org/ipac2019/papers/tuprb061.pdf
ER  - 

TY  - CONF
AU  - Zhou, G.
AU  - Jiao, Y.
AU  - Raubenheimer, T.O.
AU  - Tsai, C.-Y.
AU  - Wang, J.Q.
AU  - Wu, J.
AU  - Yang, C.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Coherence Time Characterization for Self-Amplified Spontaneous Emission Free-Electron Lasers
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - One of the key challenges in scientific researches based on free-electron lasers (FELs) is the characterization of the coherence time of the ultra-fast hard x-ray pulse, which fundamentally influences the interaction process between x-ray and materials. Conventional optical methods, based on autocorrelation, is very difficult to realize due to the lack of mirrors. Here, we experimentally demonstrate a conceptually new coherence time characterization method and a coherence time of 174.7 attoseonds has been measured for the 6.92 keV FEL pulses at Linac Coherent Light Source. In our experiment, a phase shifter is adopted to control the cross-correlation between x-ray and microbunched electrons. This approach provides critical temporal coherence diagnostics for x-ray FELs, and is decoupled from machine parameters, applicable for any photon energy, radiation brightness, repetition rate and FEL pulse duration, etc.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 1820
EP  - 1823
KW  - electron
KW  - FEL
KW  - laser
KW  - free-electron-laser
KW  - radiation
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPRB062
UR  - http://jacow.org/ipac2019/papers/tuprb062.pdf
ER  - 

TY  - CONF
AU  - Pei, Y.J.
AU  - Cao, L.
AU  - Chen, Q.S.
AU  - Feng, G.
AU  - Fu, Q.
AU  - He, X.Y.
AU  - Hong, Y.
AU  - Hu, T.
AU  - Huang, G.
AU  - Jia, D.
AU  - Lu, P.
AU  - Lu, S.
AU  - Shang, L.
AU  - Shen, L.G.
AU  - Sun, B.G.
AU  - Tan, P.
AU  - Tang, Zh.X.
AU  - Wang, W.
AU  - Wang, X.Q.
AU  - Wei, W.
AU  - Xiong, Y.Q.
AU  - Zhang, F.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Commissioning of a Compact THz Source Based on FEL
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - The layout of the THz source based on FEL was de-scribed in this paper. The THz source was based on a FEL which was composed of a compact 8-14MeV LINAC, undulator, optical resonance, THz wave measurement system and so on. The facility was designed in 2013 and the typical running parameter got in 2017 were as the following: energy is of 12.7MeV, energy spread is of 0.3%, macro-pulse is of 4 μs, pulse length of micro-pulse is of 6ps, emittance is of 24 mm.mrad. After that the ma-chine was commissioning for production THz radiation. In November 2018, the THz wave was test and got THz wave signal, the spectrum was also got. This year, we plan to measure the output power of the THz source.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 2030
EP  - 2032
KW  - linac
KW  - FEL
KW  - undulator
KW  - cavity
KW  - radiation
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPTS046
UR  - http://jacow.org/ipac2019/papers/tupts046.pdf
ER  - 

TY  - CONF
AU  - Yang, P.
AU  - Chen, H.M.
AU  - Feng, G.Y.
AU  - Hu, T.
AU  - Li, J.J.
AU  - Lu, Y.
AU  - Zhang, S.C.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Conceptual Design of a High-Performance Injector Based on Rf-Gated Gridded Thermionic Gun for Thz Fel
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - Free-Electron Laser (FEL) has higher requirements on electron beam properties, for example, low transverse emittance, small energy spread, short bunch length and high peak current. Taking compactness and economy into account, we aim to design a high-performance linear accelerator based on a RF-gated gridded thermionic electron gun, which will be used as the injector of the oscillator-type THz FEL facility at Huazhong University of Science and Technology of China. The RF-gated grid will be modulated with the fundamental and 3rd harmonic microwave of the LINAC frequency, which will be very helpful to get high electron capture efficiency and short bunch length. Concerning velocity bunching effect in the LINAC, electron bunch with good symmetry of current profile and bunch length less than 10 ps can be obtained at the exit of the injector. In this paper, design and beam dynamics simulation for the high-performance injector are presented.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 2046
EP  - 2049
KW  - gun
KW  - electron
KW  - linac
KW  - cathode
KW  - bunching
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPTS052
UR  - http://jacow.org/ipac2019/papers/tupts052.pdf
ER  - 

TY  - CONF
AU  - Sirvinskaite, R.
AU  - Cropper, M.D.
AU  - Hannah, A.N.
AU  - Malyshev, O.B.
AU  - Valizadeh, R.
AU  - Wang, S.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Electron Stimulated Desorption from Cryogenic NEG-Coated Surfaces
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - Non-Evaporable Getter (NEG) coating has been used for years in many particle accelerators due to its advantages like evenly distributed pumping speed, low thermal outgassing, and low photon, electron and ion stimulated desorption yields. Although NEG coating has been tested at room temperatures intensively, there is little data on its behaviour at cryogenic temperatures. Tests in this environment are important for the Future Circular Collider (FCC) study and other accelerator facilities where the operational conditions of the beam screen are restricted to cryogenic temperatures. This work will provide some preliminary results on NEG properties at low temperatures, e.g. pumping speed and capacity, as well as its behaviour under electron bombardment, where electron stimulated desorption (ESD) yields will be calculated. The ternary Ti-Zr-V coating, deposited with dense and columnar structure, will be the first material to be tested at cryogenic temperatures in ASTeC Daresbury laboratory. The results were compared with the ones obtained at room temperature, offering an insight into the behaviour of NEG-coated cryogenic chambers when beam-induced effects are present.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 2193
EP  - 2196
KW  - vacuum
KW  - electron
KW  - cryogenics
KW  - experiment
KW  - site
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPTS114
UR  - http://jacow.org/ipac2019/papers/tupts114.pdf
ER  - 

TY  - CONF
AU  - Shang, L.
AU  - Liu, W.
AU  - Lu, Y.
AU  - Shang, F.L.
AU  - Song, W.B.
AU  - Sun, Z.B.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Status of the R&D for HALS Injection System
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - Hefei Advanced Light Source (HALS) is a diffraction-limited synchrotron radiation source proposed by the NSRL. A comprehensive R&D program funded by the local government was initiated in the end of 2017. The program focuses on the key technologies including the injection, magnets, vacuum, mechanics, RF, etc. The formal construction of HALS is estimated to begin in 2020. This paper presents the R&D of the injection system, including the fast kicker, nanosecond pulser, NLK (non-linear kicker) and the septum magnet. Test results of the prototype fast kicker, pulsed power and the NLK are given and discussed.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 2335
EP  - 2337
KW  - kicker
KW  - injection
KW  - septum
KW  - storage-ring
KW  - vacuum
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-WEPMP015
UR  - http://jacow.org/ipac2019/papers/wepmp015.pdf
ER  - 

TY  - CONF
AU  - Liu, W.
AU  - Shang, F.L.
AU  - Shang, L.
AU  - Song, W.B.
AU  - Sun, Z.B.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - The Design and Preliminary Test of a Stripline Kicker for HALS
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - Stripline kicker is an important components of both on-axis longitudinal accumulation and on-axis swap out injection schemes in HALS (Hefei Advanced Light Source). After more than one year of R&D, construction of the first prototype is completed. The kicker performance is simulated by CST. The results show that in the range of 0~1GHz, on differential mode, S11 is less than - 23.7dB. In order to facilitate installation, the extension part and PTFE bracket were designed. The assembly of kicker and feedthrough has been tested with pulse generator and network analyser.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 2338
EP  - 2341
KW  - kicker
KW  - impedance
KW  - simulation
KW  - vacuum
KW  - high-voltage
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-WEPMP016
UR  - http://jacow.org/ipac2019/papers/wepmp016.pdf
ER  - 

TY  - CONF
AU  - Song, W.B.
AU  - Liu, W.
AU  - Lu, Y.
AU  - Shang, F.L.
AU  - Shang, L.
AU  - Sun, Z.B.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - A New Nonlinear Kicker Design and Measurement
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 beam injection of HALS, a feasible injection scheme is proposed and a single-pulse nonlinear kicker has been designed for off-axis injection. The kicker has been improved on the basis of the previous designed one, and the structure of the kicker was simulated by OPERA, and the prototype has been processed and measured. The results showed that the kicker designed in this paper has less influence on stored beam and lower difficulty in location.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 2342
EP  - 2344
KW  - kicker
KW  - injection
KW  - storage-ring
KW  - lattice
KW  - simulation
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-WEPMP017
UR  - http://jacow.org/ipac2019/papers/wepmp017.pdf
ER  - 

TY  - CONF
AU  - Wang, Q.
AU  - Jiang, S.M.
AU  - Luo, Q.
AU  - Sun, B.G.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Study on the Influence of Beam Transverse Position on the Cavity Bunch Length Measurement
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - Monopole modes in the resonant cavity are wildly used to obtain the beam current and the bunch length, while dipole modes are used to measure the beam transverse position. It is generally recognized that the monopole modes are independent of the beam transverse offset. In this paper, the influence of beam transverse offset on the bunch length measurement using monopole modes is analyzed. The simulation results show that the relative error of the bunch length measurement is less than 1 % when the beam offset is within 1 mm.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 2578
EP  - 2580
KW  - cavity
KW  - simulation
KW  - dipole
KW  - electron
KW  - laser
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-WEPGW044
UR  - http://jacow.org/ipac2019/papers/wepgw044.pdf
ER  - 

TY  - CONF
AU  - Liu, X.Y.
AU  - Bopp, M.
AU  - Dehler, M.M.
AU  - Scherer, A.
AU  - Sun, B.G.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Design of Resonant Stripline BPM for an IR-FEL Project at NSRL
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - This paper presents the design of a 476MHz resonant stripline beam position monitor (BPM) for an IR-FEL machine at NSRL. This type of BPM was developed based on stripline BPM by moving the coupling feedthrough closer to the short end downstream. This modification introduces a resonance that gives this BPM a better capability to detect lower beam currents compared to broadband devices like button and stripline BPM. Meanwhile, the change is small enough to use the same type of electronics [1-3]. In the following sections, the basic principle, nonlinear effect, sensitivity, the filtered sum and difference signals, and the mechanical design of this BPM will be mainly discussed.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 2665
EP  - 2667
KW  - FEL
KW  - dipole
KW  - electron
KW  - vacuum
KW  - emittance
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-WEPGW080
UR  - http://jacow.org/ipac2019/papers/wepgw080.pdf
ER  - 

TY  - CONF
AU  - Wang, G.
AU  - Lin, X.
AU  - Tang, Y.G.
AU  - Wu, C.-F.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Design of Two Types of X-Band High Power Directional Coupler
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - The directional coupler is one of the most widely used components in many microwave systems, which is used to distribute the power of the input microwave signal according to a desired ratio. Directional coupler may be a three-port component or a four-port component with certain specification such as frequencies, bandwidth and structure. To meet the requirements of stable coupling degree and high directivity, we designed two types of directional coupler working at 11.424 GHz with high power handling capacity. One consists of two parallel rectangular waveguides with four holes drilled along the central line of the narrow-wall for coupling the electromagnetic power from the main-waveguide to the sub-waveguide which is called H-plane directional coupler. Simulations show that the coupling degree of H-face directional coupler is 49.9 dB and the directivity is 54.5 dB .The peak electric field is about 29MV/m while operating at 200 MW peak power. The other consists of a circular main-waveguide transmitting TM01 mode and a rectangular sub-waveguide transmitting TE10 mode, called circular-rectangle waveguide directional coupler. These two waveguide are connected by six holes drilled on the side of the circular main-waveguide and along the central line of the wide-wall of the sub-waveguide. The coupling degree of this directional coupler is 50.14 dB and the directivity is 37.93 dB due to the simulation. The bandwidth is about 800MHz. The peak electric field is 404.5V/m while operating at 200 MW peak power. Comparing with the H-plane directional coupler, peak electric field of this directional coupler is lower. Low peak electric field can reduce the risk of RF breakdown and the Multipactor effect, which ensures the stable high power operation of the directional coupler.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 2928
EP  - 2930
KW  - GUI
KW  - coupling
KW  - simulation
KW  - scattering
KW  - operation
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-WEPRB052
UR  - http://jacow.org/ipac2019/papers/weprb052.pdf
ER  - 

TY  - CONF
AU  - Zhao, Y.K.
AU  - Li, W.
AU  - Sun, B.G.
AU  - Tang, Y.G.
AU  - Wu, F.F.
AU  - Zhou, T.Y.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Design of the Multiplexing Optical Measurement System for a Pre-bunched THz Free Electron Laser
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - A new and compact a pre-bunched terahertz (THz) free electron laser (FEL) at the National Synchrotron Radiation Laboratory, University of Science and Technology of China is being constructed and aims to generate the tunable radiation frequency ranges from 0.5 THz to 5 THz at 11-18 Mev electron energy. This system is expected to use for imaging, basic researches as well as industrial applications as a result of the significant merits of simple, compact and cost-effective. Due to the THz laser measurement system plays an important part in the pre-bunched THz FEL facility. Therefore, a multiplexing THz laser sensing measurement system model is developed for measuring the output laser power and the optical spectrum of THz radiation with the excellent advantages of robustness, high sensitivity and low-cost in this paper.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 2931
EP  - 2933
KW  - laser
KW  - radiation
KW  - detector
KW  - FEL
KW  - electron
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-WEPRB054
UR  - http://jacow.org/ipac2019/papers/weprb054.pdf
ER  - 

TY  - CONF
AU  - Wang, S.W.
AU  - Li, J.Y.
AU  - Wang, Y.G.
AU  - Xu, W.
AU  - Xuan, K.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Optimization of a Low-Alpha Lattice for the HLS-II 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  - To generate terahertz radiation at HLS-II, a low-alpha lattice scheme is proposed. The new lattice can reduce the bunch length in the storage ring, thus enhancing the coherent synchrotron radiation in the THz region. In this paper, the design and optimization of a low-alpha lattice is reported. The new lattice preserves the symmetry of nominal lattice and reduces the first and second order momentum factor at the cost of increasing maximum beta function and natural emittance. The bunch length is tracked and the result shows that the low-alpha lattice can effectively compress bunches in the storage ring. The performance of this low-alpha lattice can be further studied and improved.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 3360
EP  - 3362
KW  - lattice
KW  - storage-ring
KW  - quadrupole
KW  - dynamic-aperture
KW  - sextupole
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-WEPTS103
UR  - http://jacow.org/ipac2019/papers/wepts103.pdf
ER  - 

TY  - CONF
AU  - Chen, T.
AU  - Li, W.
AU  - Pei, Y.J.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Design of the Condenser System and Imaging System for a UEM
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - The ultrafast electron microscope provides a useful tool for exploring fine structure and observing dynamic process at nanometer and picosecond scale, which has been extensively applied in chemistry and biological field. After emitting from the electron gun, electron beams are focused on the stage sample by the condenser system and then be projected by the imaging system on the screen. In the present study, a two-lens condenser system is simulated by Parmela and a three-lens imaging system is designed using thin-lens approximation. Besides, the shape factor of metallic spheres which have different radius for perturbation method is measured, which is conductive to measuring the Z/Q parameter and the electric field along the axis of the C-band 3MeV photocathode gun for the UEM.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 3485
EP  - 3487
KW  - electron
KW  - gun
KW  - experiment
KW  - cathode
KW  - cavity
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-THPMP016
UR  - http://jacow.org/ipac2019/papers/thpmp016.pdf
ER  - 

TY  - CONF
AU  - Chen, X.
AU  - Li, C.
AU  - Liu, G.
AU  - Shao, Z.X.
AU  - Song, Y.
AU  - Wang, J.G.
AU  - Xuan, K.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - ALARM SYSTEM OF IRFEL AT NSRL
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - An InfraRed Free Electron Laser Light (IRFEL) is under commissioning at National Synchrotron Radiation Laboratory (NSRL). The control system of IRFEL is a distributed system based on Experimental Physics and Industrial Control System (EPICS). The alarm system is an essential part of the control system. It is developed based on the software Phoebus. The module named "Alarms" in Phoebus can store states and configuration information of the Process Variable (PV) in the Kafka topics. To meet our requirements, 3 kinds of alarm message distribution applications are developed, i.e. Web-Based GUI, WeChat and SMS. This paper will introduce the alarm system architecture and the implementations of the applications for alarm message distribution.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 3896
EP  - 3899
KW  - FEL
KW  - GUI
KW  - controls
KW  - interface
KW  - EPICS
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-THPRB038
UR  - http://jacow.org/ipac2019/papers/thprb038.pdf
ER  - 

TY  - CONF
AU  - Xie, Z.Y.
AU  - Li, C.
AU  - Liu, G.
AU  - Shao, Z.X.
AU  - Song, Y.
AU  - Wang, J.G.
AU  - Xuan, K.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Upgrade of the Historical Data Query and Analysis System for HLS-II
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - The current historical data query and analysis system for the Hefei Light Source II (HLS-II) was developed with Apache Struts2. However, Apache Struts2 need to be fixed from time to time to avoid being attacked. Therefore, a new system based on Spring Boot and Vue.js is developed. Meanwhile, the performance of the system is optimized, and the radiation monitor module is added. This paper will detail the system architecture and software implementation.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 3928
EP  - 3930
KW  - radiation
KW  - database
KW  - status
KW  - real-time
KW  - operation
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-THPRB053
UR  - http://jacow.org/ipac2019/papers/thprb053.pdf
ER  - 

TY  - CONF
AU  - Chen, L.J.
AU  - Jia, Q.K.
AU  - Li, M.
AU  - Li, P.
AU  - Wang, J.
AU  - Wu, D.
AU  - Xiao, D.X.
AU  - Yan, L.G.
AU  - Yang, X.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Optimization of Staggered Array Undulator
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - The staggered array undulator consists of staggered poles and solenoid coils that form a periodically aligned transverse magnetic field in the pole gap. The addition of magnets in the longitudinal gap between the poles further enhances the peak field strength of the undulator. A method of enhancing the peak field strength of the undulator using cryogenic temperature permanent magnets and adding side magnets has been studied. The remanence of the magnet will increase at low temperatures and the peak field strength of the undulator will increase. The side magnets do not increase the maximum peak field strength of the undulator, but can reduce the solenoid magnetic field requirements and reduce the solenoid volume and cost. The influence of the special magnetic pole and magnet shape on the peak field strength of the undulator has also been studied.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 4171
EP  - 4173
KW  - undulator
KW  - solenoid
KW  - cryogenics
KW  - electron
KW  - site
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-THPTS029
UR  - http://jacow.org/ipac2019/papers/thpts029.pdf
ER  - 

TY  - CONF
AU  - Shao, J.Q.
AU  - Chen, C.
AU  - Ge, X.Q.
AU  - Li, W.
AU  - Wang, S.
AU  - Wang, Y.
AU  - Wei, W.
AU  - Zhang, B.
AU  - Zhang, Y.X.
AU  - Zhu, B.L.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Preparation of Titanum-Zirconium-Vanadium Films by Quantitative Deposition
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - TiZrV has been used in vacuum technology and electric vacuum devices due to its high pumping speed and low activation temperature in recent years. At the same time, many preparation methods have been developed. Different from the current coating method of magnetron sputtering, this paper discusses the preparation of thin film coating from the viewpoint of vacuum sintering, which is flexible in design and more suitable for operation. Based on the analysis of the surface morphology of the sintered film, the feasibility and operability of the experimental method were explored from the surface compactness of the getter.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 4210
EP  - 4212
KW  - vacuum
KW  - experiment
KW  - electron
KW  - ECR
KW  - operation
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-THPTS045
UR  - http://jacow.org/ipac2019/papers/thpts045.pdf
ER  - 

TY  - CONF
AU  - Chen, C.
AU  - Wang, L.
AU  - Zhang, H.R.
AU  - Zhang, T.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - The Limited B-Field Integral of Superconducting Longitudinal Gradient Bend Magnet
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - The National Synchrotron Radiation Laboratory (NSRL) is planning a fourth generation diffraction-limited light source–Hefei Advanced Light Source (HALS), it is based on a seven-bend achromat lattice providing an ultralow natural emittance of 34 pm rad. The emittance can be even lower with the use of longitudinal gradient bends (LGBs) and anti-bends (ABs). The designed energy for HALS is 2.4 GeV, superconducting LGB might be employed instead of normal bending magnet since it can improve radiated beam critical energy to hard x-ray regions without using up any straight sections. To get a peak field about 6 T and small B-field profile full width half maximum, SLS-2 type LGB is considered. In this paper, the limited B-field integral (along the beam path) is trying to be find with some restrictions.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 4213
EP  - 4214
KW  - simulation
KW  - emittance
KW  - storage-ring
KW  - synchrotron-radiation
KW  - radiation
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-THPTS046
UR  - http://jacow.org/ipac2019/papers/thpts046.pdf
ER  - 

TY  - CONF
AU  - Zhang, B.
AU  - Chen, C.
AU  - Ren, Z.L.
AU  - Wang, X.Q.
AU  - Xu, H.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Design of Longitudinal Gradient Bending Magnet of HALS
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - Hefei Advanced Light Source (HALS) is a diffraction limited light source, which was proposed and expected to be built in the next few years by National Synchrotron Radiation Laboratory (NSRL) of China. Just like other new light sources, longitudinal gradient bending magnet (LGB) will be adopted to suppress the beam emittance. The magnet consists of 7 modules with different magnet-ic field. Each module has yoke and poles with the same size but different amount of permanent magnet to gener-ate field gradient. FeNi alloy is used to shunt magnetic flux and thus improve the temperature stability. Correc-tor coil or movable wedge can be used to adjust the field. Impact of magnetization direction error of permanent magnet block and parallelism error of poles on multi-poles is also evaluated.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 4215
EP  - 4217
KW  - multipole
KW  - permanent-magnet
KW  - synchrotron
KW  - lattice
KW  - ECR
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-THPTS048
UR  - http://jacow.org/ipac2019/papers/thpts048.pdf
ER  - 

TY  - CONF
AU  - Chen, J.X.
AU  - He, X.Y.
AU  - Wang, W.
AU  - Zhang, H.T.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Design of a CCD-based Laser Alignment Detection System
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - Accelerator online alignment technology is an important means for accelerator stability detecting. A CCD-based laser alignment detection system is designed for the linear accelerator, and the detection distance of the system could reach 100m. The reference comparison method is used to detect the laser imaging position acquired by the reference detector at different times, and to obtain the relative positional deviation of the measurement reference or the tested objects. Through the measurement error analysis, the precision of the system is expected to reach ±10μm.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 4311
EP  - 4313
KW  - laser
KW  - alignment
KW  - detector
KW  - controls
KW  - vacuum
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-THPTS086
UR  - http://jacow.org/ipac2019/papers/thpts086.pdf
ER  -