TY - CONF AU - Dovlatyan, L. AU - Antonsen, T.M. AU - Beaudoin, B.L. AU - Haber, I. AU - Matthew, D.B. AU - Ruisard, K.J. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Preliminary Lattice Studies for the Single-Invariant Optics Experiment at the University of Maryland J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - A novel approach to transverse resonance suppression in next generation high-intensity accelerators is the use of nonlinear optical elements to induce large tune spreads which result in reduced responses to resonance driving perturbations*. In order to test this theory, we have built and characterized an octupole channel insert for use in the University of Maryland Electron Ring (UMER). This paper presents experimental lattice studies using a low space-charge intensity beam at an energy of 10keV with a beam current of ~150uA, tune depression < 0.005, and unnormalized RMS emittance of 4.3 mm-mr. We apply beam based measurement techniques in order to evaluate the quality of our single-invariant lattice and better understand the nonlinearities created by the octupole channel. PB - JACoW Publishing CP - Geneva, Switzerland SP - 367 EP - 370 KW - lattice KW - experiment KW - octupole KW - optics KW - resonance DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW105 UR - http://jacow.org/ipac2019/papers/mopgw105.pdf ER - TY - CONF AU - Aleksandrov, A.V. AU - Cousineau, S.M. AU - Ruisard, K.J. AU - Tzoganis, V. AU - Zhang, Z.L. AU - Zhukov, A.P. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Commissioning of the New Experimental FODO Line at the SNS Beam Test Facility J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The SNS Beam Test Facility consists of a 2.5MeV proton accelerator and a beam line with various diagnostics for high intensity beam dynamics study. A FODO line consisting of 19 quadrupole magnets and a large dynamic range emittance monitor has been added recently. The new setup is design for experimental study of mechanisms of halo formation in mismatched high intensity beams. We present results of the new beam line commissioning with beam. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1164 EP - 1166 KW - rfq KW - emittance KW - MMI KW - simulation KW - optics DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPTS120 UR - http://jacow.org/ipac2019/papers/mopts120.pdf ER - TY - CONF AU - White, G.R. AU - Cobb, T.M. AU - Dalesio, L.R. AU - Davidsaver, M.A. AU - Hartman, S.M. AU - Hickin, D.G. AU - Johnson, A.N. AU - Junkes, H. AU - Kasemir, K.-U. AU - Konrad, M.G. AU - Korhonen, T. AU - Kraimer, M.R. AU - Lange, R. AU - Pearson, M.R. AU - Rivers, M.L. AU - Sekoranja, M. AU - Shankar, M.V. AU - Shen, G. AU - Shroff, K. AU - Veseli, S. AU - Vodopivec, K. AU - Zimoch, D. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - The EPICS Software Framework Moves from Controls to Physics J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The Experimental Physics and Industrial Control System (EPICS), is an open-source software framework for high-performance distributed control, and is at the heart of many of the world’s large accelerators and telescopes. Recently, EPICS has undergone a major revision, with the aim of better computing supporting for the next generation of machines and analytical tools. Many new data types, such as matrices, tables, images, and statistical descriptions, plus users’ own data types, now supplement the simple scalar and waveform types of the former EPICS. New computational architectures for scientific computing have been added for high-performance data processing services and pipelining. Python and Java bindings have enabled powerful new user interfaces. The result has been that controls are now being integrated with modelling and simulation, machine learning, enterprise databases, and experiment DAQs. We introduce this new EPICS (version 7) from the perspective of accelerator physics and review early adoption cases in accelerators around the world. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1216 EP - 1218 KW - EPICS KW - controls KW - detector KW - database KW - experiment DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUZZPLM3 UR - http://jacow.org/ipac2019/papers/tuzzplm3.pdf ER - TY - CONF AU - Stockli, M.P. AU - Clemmer, M.E. AU - Cousineau, S.M. AU - Draganic, I.N. AU - Dudnikov, V.G. AU - Garnett, R.W. AU - Han, B. AU - Justice, T.A. AU - Kang, Y.W. AU - Kleinjan, D. AU - Murray, S.N. AU - Pennisi, T.R. AU - Piller, C. AU - Rouleau, G. AU - Stinson, C. AU - Welton, R.F. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Operating the SNS RF H⁻ Ion Source with a 10% Duty Factor J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The SNS (Spallation Neutron Source) (radio-frequency) RF-driven, H⁻ ion source injects ~50 mA of H⁻ beam into the SNS accelerator at 60 Hz with a 6% duty factor. It injects up to 7 A·hrs of H⁻ ions during its ~14-week service cycles, which is an unprecedented lifetime for small-emittance, high-current pulsed H⁻ ion sources. The SNS source also features unprecedented low cesium consumption and can be installed and started up in <10 h. Presently, the LANSCE (Los Alamos Neutron Science CEnter) accelerator complex in Los Alamos is fed by a filament-driven, biased converter-type H⁻ source that operates with a high plasma duty factor of 10%. It needs to be replaced every 4 weeks with a ~4 day startup phase. The measured negative beam current of 16-18 mA falls below the desired 21 mA acceptance of LANSCE’s accelerator especially since the beam contains several mA of electrons. LANSCE and SNS are exploring the possibility of using the SNS RF H⁻ source at LANSCE to increase the H⁻ beam current and the ion source lifetime while decreasing the startup time. For this purpose, the SNS H⁻ source has been tested at a 10% duty factor by operating it at 120 Hz with 840 µs plasma pulses generated with ~30 kW of 2 MHz RF power, and extracting ~25 mA around-the-clock for 28 days. This, and additional tests and other considerations are discussed in this paper. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1951 EP - 1953 KW - ion-source KW - plasma KW - electron KW - neutron KW - LEBT DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPTS009 UR - http://jacow.org/ipac2019/papers/tupts009.pdf ER - TY - CONF AU - Plum, M.A. AU - Anderson, D.E. AU - Barbier, C.N. AU - Champion, M.S. AU - Connell, M.S. AU - Galambos, J. AU - Harvey, M.M. AU - Howell, M.P. AU - Kim, S.-H. AU - Moss, J. AU - Riemer, B.W. AU - Steffey, R.W. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - SNS Proton Power Upgrade Status J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The Proton Power Upgrade (PPU) project at the Oak Ridge Spallation Neutron Source aims to double the beam power capability of the accelerator, from 1.4 to 2.8 MW. This will be done by a 30% increase in beam energy (from 1.0 to 1.3 GeV), and a 50% increase in beam current (from 25 to 38 mA averaged over a macropulse). The project is now well underway, after receiving approval to start preliminary design in April 2018. In this paper we will discuss recent technical developments in the project, including the warm linac RF system upgrade, a new topology for the high voltage converter modulators, an engineering review of the power capability of the injection dump, and a 2-MW-capability for the existing target station. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2124 EP - 2126 KW - klystron KW - power-supply KW - injection KW - DTL KW - linac DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPTS086 UR - http://jacow.org/ipac2019/papers/tupts086.pdf ER - TY - CONF AU - Brown, D.L. AU - Crofford, M.T. AU - Peters, C.C. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Optimizing Room Temperature RF Structures for Accelerator Driven System Operations J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Minimizing beam trip rates is one of the key operational goals at the Spallation Neutron Source (SNS). Trip rates are closely monitored, and real-time statistics are kept during beam operations for immediate analysis. Beam trips are automatically binned by the length of the trip along with the cause for each trip. The shortest beam trips occur with the highest frequency and those trip rates are dominated by the room temperature RF structures. There can be many causes for the RF structure malfunctions, but one area that has had a major impact on trip rates is improvement in how RF processing is done on structures after extended maintenance periods. Details about the improvement in RF conditioning will be discussed. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2993 EP - 2995 KW - vacuum KW - cavity KW - operation KW - RF-structure KW - DTL DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPRB075 UR - http://jacow.org/ipac2019/papers/weprb075.pdf ER - TY - CONF AU - Zhukov, A.P. AU - Allen, C.K. AU - Bolling, B.E. AU - Chu, C.P. AU - Dodson, T. AU - Esteban Müller, J.F. AU - Gillette, P. AU - Laface, E. AU - Laurent, P. AU - Levinsen, Y. AU - Li, M.T. AU - Li, Y. AU - Lu, X.H. AU - Milas, N. AU - Normand, G. AU - Peng, J. AU - Rosati, C. AU - Savalle, A. AU - Shishlo, A.P. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Open XAL Status Report 2019 J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The Open XAL accelerator physics software platform is being developed through an international collaboration among several facilities since 2010. This paper discusses progress in beam dynamics simulation, new RF models, and updated application framework along with new generic accelerator physics applications. We present the current status of the project, a roadmap for continued development and an overview of the project status at each participating facility. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3341 EP - 3344 KW - cavity KW - LEBT KW - linac KW - framework KW - status DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPTS096 UR - http://jacow.org/ipac2019/papers/wepts096.pdf ER - TY - CONF AU - Liu, Y. AU - Aleksandrov, A.V. AU - Cousineau, S.M. AU - Gorlov, T.V. AU - Rakhman, A. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Sequential Excitation Scheme for Laser Stripping of Hydrogen Ion Beams J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Resonant laser excitation of the electron in a hydrogen atom is essential to achieve high-efficiency laser stripping of hydrogen ion (H⁻) beam. In the laser stripping experiments recently carried out at SNS, an ultra-violet (UV) laser was used to excite the electrons in 1-GeV hydrogen atoms from the n=1 state to the n=3 state. In this talk, we propose a sequential resonant excitation scheme by using two laser beams to excite electrons in a sequence of two steps: from the n=1 state to the n=2 state and from the n=2 state to any higher state. The advantages of the sequential resonant excitation scheme include (1) lower laser power requirement due to higher transition probability in the first excitation step and (2) possibility of shifting the stripping laser wavelength from UV regime to longer wavelengths. An application of the sequential resonant excitation scheme in combination with the double-resonance optical cavity technology to the laser stripping of 1.3-GeV H⁻ beam (envisioned in the SNS proton power upgrade project) will be described. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3558 EP - 3560 KW - laser KW - photon KW - electron KW - cavity KW - proton DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPMP049 UR - http://jacow.org/ipac2019/papers/thpmp049.pdf ER - TY - CONF AU - Galambos, J. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Operations Experience of SNS at 1.4MW and Upgrade Plans for Doubling the Beam Power J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - In 2018, the SNS begins operation at the design proton beam power of 1.4 MW. This talk will present the critical technical challenges that were overcome in order to take the final step in beam power with a higher than 90% reliability. In addition, the future project of the SNS for doubling the beam power from 1.4 MW to 2.8 MW and construction of second target station will be discussed. PB - JACoW Publishing CP - Geneva, Switzerland SP - 4380 EP - 4384 KW - target KW - operation KW - proton KW - neutron KW - cryomodule DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-FRXPLM1 UR - http://jacow.org/ipac2019/papers/frxplm1.pdf ER -