IPAC2019 - List of Keywords (scattering)

Paper	Title	Other Keywords	Page
MOPGW053	Residual Gas Lifetime In High Energy Photon Source (HEPS)	electron, dynamic-aperture, vacuum, photon	210
	S.K. Tian, H.S. Xu IHEP, Beijing, People’s Republic of China
	High vacuum has always been mandatory in particle accelerators. This is especially true for circular machines, where the beam makes thousands or millions turns, and beam lifetime is heavily affected by the residual gas scattering. At the beginning of storage ring operation the lifetime was very short mostly dominated by residual gas scattering. The residual gas lifetime is comprised of the elastic and inelastic scattering on electrons and elastic and inelastic scattering on nuclei. One usually calculates only the elastic scattering on nuclei (single Coulomb scattering) and inelastic scattering on nuclei (bremsstrahlung) of the residual gas scattering lifetime component. The analytic calculation the residual gas scattering lifetime and simulations of the beam interaction with the residual gas with code will be shown in this presentation
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW053
About •	paper received ※ 15 May 2019 paper accepted ※ 19 May 2019 issue date ※ 21 June 2019
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MOPRB012	RECENT RESULTS FROM MICE ON MULTIPLE COULOMB SCATTERING AND ENERGY LOSS	emittance, detector, framework, acceleration	598
	C.G. Whyte USTRAT/SUPA, Glasgow, United Kingdom J.C. Nugent University of Glasgow, Glasgow, United Kingdom
	Funding: STFC, NSF, DOE, INFN, CHIPP and more Multiple Coulomb scattering and energy loss are well known phenomena experienced by charged particles as they traverse a material. However, from recent measurements by the MuScat collaboration, it is known that the simulation code (GEANT4) available at the time overestimated the scattering of muons in low Z materials. Updates to GEANT4 have brought the simulations in line with the MuScat data and these new models can be validated over a larger range of momentum, 170-250 MeV/c, with MICE data. This is of particular interest to the Muon Ionization Cooling Experiment (MICE) collaboration which has the goal of measuring the reduction of the emittance of a muon beam induced by energy loss in low Z absorbers. MICE took data without magnetic field suitable for multiple scattering measurements in the spring of 2016 using a lithium hydride absorber and in the fall of 2017 using a liquid hydrogen absorber. The measurement in lithium hydride is reported here along with the preliminary measurements in liquid hydrogen. In the fall of 2016 MICE took data with magnetic fields on and measured the energy loss of muons in a lithium hydride absorber. These data are all compared with the Bethe-Bloch formula and with the predictions of various models, including the default GEANT4 model.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB012
About •	paper received ※ 15 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
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MOPRB024	Beam-Gas and Beam-Thermal Photon Scattering in CEPC	photon, background, detector, factory	626
	S. Bai, J. Gao, H. Geng, D. Wang, Y. Wang, C.H. Yu, Y. Zhang IHEP, Beijing, People’s Republic of China Y. Zhang University of Chinese Academy of Sciences, Beijing, People’s Republic of China
	The Circular Electron Positron Collider (CEPC) is a proposed Higgs factory with center of mass energy of 240 GeV to measure the properties of Higgs boson and test the standard model accurately. Beam loss background in detectors is an important topic at CEPC. Beam-Gas scattering (BG) and Beam-Thermal photon scattering (BTH), although not so serious as Radiative Bhabha scattering (RBB) and Beamstrahlung (BS), are also important components of the beam induced backgrounds at CEPC due to the beam lifetime. In this paper, we evaluated the beam-gas and beam-thermal photon scattering in simulation and designed collimators to suppress the radiation level on the machine and the detector.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB024
About •	paper received ※ 28 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPRB060	Simulating Novel Collimation Schemes for High-Luminosity LHC With Merlin++	proton, collimation, simulation, electron	708
	S.C. Tygier, R.B. Appleby UMAN, Manchester, United Kingdom R.J. Barlow, S. Rowan IIAA, Huddersfield, United Kingdom
	Due to the large stored beam energy in the HL-LHC new collimation technologies must be used to protect the machine. Active halo control of the proton beam halo with a Hollow Electron Lens can give a kick to protons at the edge of the beam without effecting the core. Various modes of operation are possible for example the electron lens can have a continuous current or it can be pulsed to different amplitudes for each passage of the proton beam. In this article we use Merlin++ simulations to show the performance of these modes for HL-LHC parameters. We also present recent simulations comparing scattering models in Merlin++.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB060
About •	paper received ※ 08 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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MOPTS101	Study of the Transverse Emittance Blow-Up Along the Proton Synchrotron Booster Cycle During Wire Scanner Operation	emittance, simulation, proton, brightness	1110
	A. Santamaría García, F. Antoniou, H. Bartosik, J.A. Briz Monago, G.P. Di Giovanni, A. Guerrero, J.R. Hunt, B. Mikulec, F. Roncarolo, E. Senes, V. Vlachoudis CERN, Geneva, Switzerland E. Senes Oxford University, Physics Department, Oxford, Oxon, United Kingdom
	Transverse emittance measurements with wire scanners have been extensively studied across the accelerator complex at CERN due to their important role in characterizing the beam and their complicated modeling. In recent years, this topic has been of particular interest for the LHC Injectors Upgrade (LIU) project, where a tight transverse emittance blow-up budget between the Proton Synchrotron Booster (PSB) and the Proton Synchrotron (PS) is imposed to assure the required beam brightness for the High Luminosity LHC (HL-LHC). In order to maintain a high brightness beam, any source of emittance blow-up along the PSB cycle needs to be identified and mitigated. While wire scanners have been mostly used at extraction energy in the PSB, they can also operate along the energy cycle. The scattering of the protons with the wire increases considerably at lower energies, leading to an overestimation of the beam emittance. In this contribution we present the most recent studies, focusing on precisely quantifying the blow-up created by the flying wire with measurements in an optimized set-up and compared to FLUKA simulations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS101
About •	paper received ※ 13 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
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TUPMP022	Research on Digital Scanning Power Supply Technology for Proton Therapy System	power-supply, proton, controls, radiation	1286
	J. Huang, M. Fan, J. Yang, L.G. Zhang HUST, Wuhan, People’s Republic of China T. Yu, C. Zuo Huazhong University of Science and Technology, State Key Laboratory of Advanced Electromagnetic Engineering and Technology,, Hubei, People’s Republic of China
	Funding: Work supported by The National Key Research and Development Program of China, with grant No. 11505068 Proton has great advantages in the field of cancer radiotherapy because of its good characteristic of Bragg peak. HUST-PTF is a proton therapy facility under development in Huazhong University of science and technology. It delivers the beam to the patients with a pencil beam scanning nozzle. Scanning power supplies are placed in the nozzle of the proton therapy device and they are required high accuracy, high speed and high stability. In this paper，the structure diagram of HUST-PTF is shown. The parameters of scanning magnets and its power supply are introduced. Finally, some test results of power supply are shown. The next work will debug the control system of the scanning power supply and adjust it with the scanning magnet to see if it meets the design requirements.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP022
About •	paper received ※ 19 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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TUPGW059	Studies of The Electron Beam Lifetime in Solaris Electron Storage Ring	electron, storage-ring, cavity, vacuum	1541
	R. Panas, A.M. Marendziak, A.I. Wawrzyniak, M. Wisniowski Solaris National Synchrotron Radiation Centre, Jagiellonian University, Kraków, Poland
	Solaris storage ring is a recently constructed and commissioned machine operated in decay mode. With total accumulated beam dose near to 1000 A.h the measured total lifetime has reached 16 h for 270mA of a stored current. In this paper, the beam lifetime studies are presented using measured residual gas analysis and vertical scraper position for tuned and detuned Landau cavities. It shows that for stable beam the lifetime is dominated by the interaction of the electron with residual gas (vacuum lifetime) and between electrons interaction within a bunch (Touschek lifetime). The estimated vacuum, Touschek and total beam lifetimes from theoretical analysis are also compared with the measured beam lifetime.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW059
About •	paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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TUPGW085	A Hard X-Ray Compact Compton Source at CBETA	electron, laser, photon, brilliance	1604
	K.E. Deitrick, C. Franck, G.H. Hoffstaetter, V.O. Kostroun, K.W. Smolenski Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA J. Crone, H.L. Owen UMAN, Manchester, United Kingdom B.D. Muratori STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	Compton backscattering at energy recovery linacs (ERLs) promises high flux, high energy x-ray sources in the future, made possible by high quality, high repetition rate electron beams produced by ERLs. CBETA, the Cornell-BNL ERL Test Accelerator currently being built and commissioned at Cornell, is an SRF multi-turn ERL using Non-Scaling Fixed Field Alternating-gradient (NS-FFA) arcs. CBETA has high quality design parameters with an anticipated top energy of 150 MeV on the fourth pass. The expected parameters of a Compton source at CBETA include a top x-ray energy of over 400 keV with a flux on the order of 10¹² ph/s. In this paper, we present anticipated parameters and potential applications in science and engineering for this source.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW085
About •	paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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TUPGW110	Improvement of Touschek Lifetime by Higher Harmonic RF Cavity in the SPS Storage Ring	cavity, storage-ring, operation, synchrotron	1669
	T. Phimsen, N. Juntong, P. Sudmuang SLRI, Nakhon Ratchasima, Thailand B.C. Jiang Shanghai Advanced Research Institute, Pudong, Shanghai, People’s Republic of China Z.T. Zhao SSRF, Shanghai, People’s Republic of China
	Siam Photon Source (SPS), located at Nakhon Ratchasima, Thailand, is a synchrotron light source with the beam energy of 1.2 GeV. User operation is performed in beam decay mode with the maximum current of 150 mA. Beam lifetime is about 12 hours at the beam current of 100 mA. Beam injection is carried out twice a day, and even with full energy, it takes roughly 30 minutes. Beam lifetime in the SPS storage ring is limited by Touschek scattering and strongly depends on operation conditions. Higher harmonic RF cavity is a proven method to increase the beam lifetime and suppressing coupled bunch instabilities through Landau damping effect. If the beam lifetime is increased for examples, to be double, only one injection per day would be needed. In this study, an improvement of Touschek lifetime by passive harmonic RF cavity is investigated.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW110
About •	paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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WEXXPLS2	Accelerator Vacuum Windows: A Review of Past Research and a Strategy for the Development of a New Design for Improved Safety and Longevity for Particle Accelerators	vacuum, Windows, radiation, experiment	2237
	C.R. Ader, M.L. Alvarez, J.S. Batko, R. Campos, M.W. McGee, A.C. Watts Fermilab, Batavia, Illinois, USA
	Funding: Fermi National Accelerator Laboratory Vacuum window research continues at Fermilab and this paper will examine cost effective, consistent designs which can have a significant impact on accelerator laboratories in terms of safety and cost. Issues such as the design, materials, analysis, testing and fabrication are addressed, including beam scattering and materials cost-benefit analysis and examining potential material substitutes for beryllium. A previous research paper has examined current fabrication and design techniques and also failure modes at Fermi, and this paper focuses on emerging and novel technologies for vacuum window fabrication. Many different paths have been taken by High Energy Physics (HEP) Laboratories throughout the world with varying success. The history of vacuum window development is extensive and not well defined, and a matrix of the research already completed on materials and joint design for vacuum windows will be shown. This report finally includes a treatise for vacuum window technology and a view towards emerging designs and materials and discusses future advances of research such as fabrication techniques including additive manufacturing and ultrasonic welding. Further exploration into these would prove beneficial to developing vacuum windows that are safer and stronger while being more transparent to the beam.
	Slides WEXXPLS2 [3.139 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEXXPLS2
About •	paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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WEPMP038	Combined MCNP/Turtle Simulation of the SINQ Beam Line at PSI-HIPA	simulation, target, proton, optics	2410
	D. Reggiani, D.C. Kiselev, M. Seidel, V. Talanov, M. Wohlmuther PSI, Villigen PSI, Switzerland
	With a nominal beam power of nearly 1.4 MW, the PSI High Intensity Proton Accelerator (HIPA) complex is currently at the forefront of the high intensity frontier of particle accelerators. A key issue of such facilities is the minimization of beam losses that could lead to excessive activation of beam line components. At HIPA, the SINQ beam line is particularly subject to relatively large losses since it receives the highly divergent beam scattered off a 40 or 60 mm thick muon production graphite target (TE). So far, for HIPA, beam line simulations have been carried out only by means of the matrix multiplication codes TRANSPORT and TURTLE. Although very efficient, such tools do not allow a precise determination of beam losses whenever targets and collimators are substantially affecting the beam optics. A true understanding of how beam halo and the low momentum tail contribute to the measured losses can only be achieved by complementing the traditional simulations techniques by a tool that can transport beam particles in different materials and, at the same time, handle complex geometries like the ones of collimators situated in the beam line. Moreover, such an improved beam line simulation would give a significant contribution in evaluating the feasibility of the SINQ beam rotation system currently under study. In this paper we present a simulation of the SINQ beam line combining MCNP models of TE and collimator sections with the TURTLE computation of the magnetic channel.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP038
About •	paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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WEPMP048	Development of Spin Rotator and an Absolute Polarimeter for Polarized He-3 at BNL	dipole, polarization, solenoid, target	2440
	D. Raparia, G. Atoian, S. Ikeda, R.F. Lambiase, M. Okamura, A. Poblaguev, J. Ritter, S. Trabocchi, A. Zelenski BNL, Upton, Long Island, New York, USA R. Milner, M.M. Musgrave MIT, Cambridge, Massachusetts, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. EBIS Preinjector will provide longitudinally polarized 3He++ ions with about 80% polarization and 5.10¹¹ particles per bunch at 6 MeV, which must be rotated to vertical direction before it ions are injected into the Booster. The 3He++ longitudinal polarization is first rotated to the transverse direction by the 21.5° bending magnet. Then the solenoid spin-rotator rotates the spin to the vertical direction. The spin-rotator will be a pulsed solenoid with a reversible field to enable spin flips. The vertically polarized beam will be returned back to the straight HEBT line by the system of three dipole magnets after the spin rotator solenoid. The low-energy polarimeter can be installed in the straight beam line section after the second dipole magnet. To measure transverse (vertical) polarization of the 3He beam at 5-6 MeV, the spin correlated asymmetry of 3He scattering on a 4He gas target (~5 Torr) will be measured with left/right symmetric strip detectors. Paper will present status of the project.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP048
About •	paper received ※ 19 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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WEPGW106	Statistical Measurement of Longitudinal Beam Halo in Fermilab Recycler	experiment, detector, data-acquisition, booster	2742
	E. Prebys, T.M. Nguyen UCD, Davis, California, USA A.S. Dyshkant, D. Hedin Northern Illinois University, DeKalb, Illinois, USA A. Gaponenko Fermilab, Batavia, Illinois, USA R.J. Hooper Lewis University, Romeoville, Illinois, USA M. Jones Purdue University, West Lafayette, Indiana, USA
	Funding: This work supported by US Department of Energy Contract DE-AC02-07CH11359 The formation of non-Gaussian halo in both the transverse and longitudinal dimensions of beam bunches has been notoriously difficult both the model and to measure. We present a technique to measure the longitudinal halo of 2.5 MHz bunches in the Fermilab Recycler, which have been formed for the g-2 anomalous magnetic moment experiment. While out of time beam is not a particular concern to this experiment, it is a key issue for the subsequent Mu2e rare muon decay experiment, which will use the same bunch formation procedure. Our measurement relies on a statistical technique, in which a small fraction of the beam is scattered from the primary collimation foil in the recycler, and then is detected by a charge telescope consisting of quartz Cherenkov radiators and photomultiplier tubes. By integrating over many revolutions, the time profile of longitudinal halo (out-of-time beam) can be measured down to less than a 10^-5 fractional level, relative to in-time beam. These results can then be compared to simulations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW106
About •	paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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WEPRB052	Design of Two Types of X-Band High Power Directional Coupler	GUI, coupling, simulation, operation	2928
	G. Wang, X. Lin, Y.G. Tang, C.-F. Wu USTC/NSRL, Hefei, Anhui, People’s Republic of China
	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.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB052
About •	paper received ※ 27 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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WEPTS002	Study of a Proton Therapy Beamline for Eye Treatment with Beam Delivery Simulation (BDSIM) and an In-House Tracking Code	simulation, proton, neutron, site	3088
	E. Gnacadja, C. Hernalsteens, N. Pauly, R. Tesse ULB - FSA - SMN, Bruxelles, Belgium S.T. Boogert, L.J. Nevay, W. Shields JAI, Egham, Surrey, United Kingdom
	The complete modelling of passive scattering proton therapy systems is challenging and requires simulation tools that have capabilities in both beam transport and in the detailed description of particle-matter interactions. Beam Delivery Simulation (BDSIM) allows the seamless simulation of the transport of particles in a beamline and its surrounding environment. A complete 3D model can be built from Geant4, CLHEP and ROOT to provide a complete analysis of the primary beam tracking. This capability is applied to the eye treatment proton therapy machine part of the IBA Proteus Plus product line. Those simulations are compared with a fast in-house particle tracking code with a semi-analytical model of Multiple Coulomb Scattering. The preliminary results leading to the detailed knowledge of the beamline performance are discussed in detail.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS002
About •	paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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WEPTS026	Generalised Scattering Module in SixTrack 5	target, lattice, experiment, proton	3156
	K.N. Sjobak University of Oslo, Oslo, Norway H. Burkhardt, R. De Maria, V.K.B. Olsen CERN, Geneva, Switzerland
	Funding: Research Council of Norway, project 255196, and HL-LHC WP8 A generalised scattering module has recently been added to SixTrack. This module enables the use of arbitrary generators and target profiles. Presently, a simple model of elastic scattering and a coupling to Pythia8 have been implemented. This makes it possible to use SixTrack for studies of aperture losses and beam lifetime as a result of beam–beam scattering.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS026
About •	paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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WEPTS043	SixTrack Version 5: Status and New Developments	simulation, electron, collimation, HOM	3200
	R. De Maria, J. Andersson, L. Field, M. Giovannozzi, P.D. Hermes, N. Hoimyr, G. Iadarola, S. Kostoglou, E.H. Maclean, E. McIntosh, A. Mereghetti, J. Molson, V.K.B. Olsen, D. Pellegrini, T. Persson, M. Schwinzerl CERN, Geneva, Switzerland B. Dalena, T. Pugnat CEA-IRFU, Gif-sur-Yvette, France K.N. Sjobak University of Oslo, Oslo, Norway I. Zacharov EPFL, Lausanne, Switzerland
	SixTrack Version 5 is a major SixTrack release that introduces new features, with improved integration of the existing ones, and extensive code restructuring. New features include dynamic-memory management, scattering-routine integration, a new initial-condition module, and reviewed post-processing methods. Existing features like on-line aperture checking and Fluka-coupling are now enabled by default. Extensive performance regression tests have been developed and deployed as part of the new-release generation. The new features of the tracking environment developed for the massive numerical simulations will be discussed as well.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS043
About •	paper received ※ 17 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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THPGW035	Development of Yb-Based Laser System for Crab Crossing Laser-Compton Scattering	laser, electron, luminosity, experiment	3657
	R. Morita, Y. Koshiba, S. Ota, M. Washio Waseda University, Tokyo, Japan T. Higashiguchi Center for Optical Research and Education, Utsunomiya University, Utsunomiya, Japan K. Sakaue The University of Tokyo, The School of Engineering, Tokyo, Japan J. Urakawa KEK, Ibaraki, Japan
	Funding: This work was supported by JSPS KAKENHI 18H0123. We are going to demonstrate the principle of crab crossing in laser-Compton scattering which creates head-on collision in a pseudo manner to enhance the intensity of laser-Compton X-ray. When the electron beam is tilted by half of the collision angle, the scat-tered X-rays becomes the largest. Calculation shows that more than threefold luminosity will be achieved in our system and could be larger luminosity depending on the beam parameters. The intensity of scattered light can be efficiently enhanced by using a collision laser with high intensity, high quality and ultrashort pulse duration. Thus, we have introduced a regenera-tive amplifier using ceramics thin-disk as a collision laser and developed a dedicated laser system. In this conference, we will report on our laser system and results of crab crossing laser-Compton scattering.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW035
About •	paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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THPGW039	Moderation of Positive Muons by Helium Gas	proton, experiment, simulation, vacuum	3667
	Y. Li, Y. Bao, R. Fan, X. Li, X. Tong IHEP, Beijing, People’s Republic of China C.J. Ning, P.C. Wang IHEP CSNS, Guangdong Province, People’s Republic of China
	Funding: This work is supported by CAS, National Natural Science Foundation of China (Grant No. 11875281), and China Postdoctoral Science Foundation (Grant No. 2019M650845) Efficiently creating beams of spin-polarized positive muons with energies between eV and keV (so-called slow muon beams) is important for further development and application of muon spin rotation, relaxation, and resonance techniques. One existing moderation method involves the use of wide-band-gap materials as moderators such as rare gas solids and solid nitrogen thin films (band-gap energy between 11 eV and 22 eV). Based on this moderation method, we have studied the use of helium gas as a moderator, with the goal of producing the slow muon beam more efficiently. Because of helium’s high (24.6 eV) ionization energy and because the cross section for muonium formation is suppressed in helium gas, we expect the production of slow muons using helium gas to be highly efficient.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW039
About •	paper received ※ 01 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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THPRB095	A Simulation Framework for Photon-Particle Interactions for Laserwires and Further Applications	laser, photon, electron, simulation	4045
	S.E. Alden, S.M. Gibson, L.J. Nevay JAI, Egham, Surrey, United Kingdom
	A model has been developed for simulating photon-particle interactions with Beam Delivery Simulation (BDSIM). BDSIM is a high energy physics program that utilises the Geant4, CLHEP, and ROOT libraries to seamlessly track particles through an accelerator. The photon-particle interactions introduce the capability for modelling a range of applications in accelerator physics. One such application is a laserwire which is a minimally invasive diagnostic technique to measure beam profiles and emittance. In this paper we describe the recent implementation of inverse Compton scattering and electron stripping of Hydrogen ions. This is demonstrated on an example beamline.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB095
About •	paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019
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THPRB118	Study on the Influence of the Range Shifter Material in a Scanning Nozzle for Proton Therapy Based on Monte Carlo Method	proton, neutron, ECR, radiation	4100
	Y.C. Yu, H.D. Guo, Y.Y. Hu, X.Y. Li, Y.J. Lin, P. Tan, X.D. Tu, L.G. Zhang HUST, Wuhan, People’s Republic of China
	Range shifter plays a key role in decreasing the energy of the proton beam to realize shallow tumours treatment with the scanning nozzle in Huazhong University of Science and Technology Proton Therapy Facility (HUST-PTF). To control the transverse scattering and decrease the damage to healthy tissue caused by secondary particle, influence of the range shifter material was studied. In this paper, the Monte Carlo software Geant4 and FLUKA are applied to analyse the transport process of proton beam in the range shifters made of six different materials: PMMA, Lexan, Lucite, Polyethylene, Polystyrene, and Wax. The beam spot sizes at the iso-center with or without range shifter was calculated for the HUST-PTF scanning nozzle. The relationship between the thickness of the range shifters of the six materials and the proton energy was obtained. The secondary neutron yield at the end of the nozzle was also analysed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB118
About •	paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
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MOPGW053

Residual Gas Lifetime In High Energy Photon Source (HEPS)

electron, dynamic-aperture, vacuum, photon

210

S.K. Tian, H.S. Xu
IHEP, Beijing, People’s Republic of China

High vacuum has always been mandatory in particle accelerators. This is especially true for circular machines, where the beam makes thousands or millions turns, and beam lifetime is heavily affected by the residual gas scattering. At the beginning of storage ring operation the lifetime was very short mostly dominated by residual gas scattering. The residual gas lifetime is comprised of the elastic and inelastic scattering on electrons and elastic and inelastic scattering on nuclei. One usually calculates only the elastic scattering on nuclei (single Coulomb scattering) and inelastic scattering on nuclei (bremsstrahlung) of the residual gas scattering lifetime component. The analytic calculation the residual gas scattering lifetime and simulations of the beam interaction with the residual gas with code will be shown in this presentation

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paper received ※ 15 May 2019 paper accepted ※ 19 May 2019 issue date ※ 21 June 2019

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MOPRB012

RECENT RESULTS FROM MICE ON MULTIPLE COULOMB SCATTERING AND ENERGY LOSS

emittance, detector, framework, acceleration

598

C.G. Whyte
USTRAT/SUPA, Glasgow, United Kingdom
J.C. Nugent
University of Glasgow, Glasgow, United Kingdom

Funding: STFC, NSF, DOE, INFN, CHIPP and more
Multiple Coulomb scattering and energy loss are well known phenomena experienced by charged particles as they traverse a material. However, from recent measurements by the MuScat collaboration, it is known that the simulation code (GEANT4) available at the time overestimated the scattering of muons in low Z materials. Updates to GEANT4 have brought the simulations in line with the MuScat data and these new models can be validated over a larger range of momentum, 170-250 MeV/c, with MICE data. This is of particular interest to the Muon Ionization Cooling Experiment (MICE) collaboration which has the goal of measuring the reduction of the emittance of a muon beam induced by energy loss in low Z absorbers. MICE took data without magnetic field suitable for multiple scattering measurements in the spring of 2016 using a lithium hydride absorber and in the fall of 2017 using a liquid hydrogen absorber. The measurement in lithium hydride is reported here along with the preliminary measurements in liquid hydrogen. In the fall of 2016 MICE took data with magnetic fields on and measured the energy loss of muons in a lithium hydride absorber. These data are all compared with the Bethe-Bloch formula and with the predictions of various models, including the default GEANT4 model.

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paper received ※ 15 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

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MOPRB024

Beam-Gas and Beam-Thermal Photon Scattering in CEPC

photon, background, detector, factory

626

S. Bai, J. Gao, H. Geng, D. Wang, Y. Wang, C.H. Yu, Y. Zhang
IHEP, Beijing, People’s Republic of China
Y. Zhang
University of Chinese Academy of Sciences, Beijing, People’s Republic of China

The Circular Electron Positron Collider (CEPC) is a proposed Higgs factory with center of mass energy of 240 GeV to measure the properties of Higgs boson and test the standard model accurately. Beam loss background in detectors is an important topic at CEPC. Beam-Gas scattering (BG) and Beam-Thermal photon scattering (BTH), although not so serious as Radiative Bhabha scattering (RBB) and Beamstrahlung (BS), are also important components of the beam induced backgrounds at CEPC due to the beam lifetime. In this paper, we evaluated the beam-gas and beam-thermal photon scattering in simulation and designed collimators to suppress the radiation level on the machine and the detector.

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paper received ※ 28 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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MOPRB060

Simulating Novel Collimation Schemes for High-Luminosity LHC With Merlin++

proton, collimation, simulation, electron

708

S.C. Tygier, R.B. Appleby
UMAN, Manchester, United Kingdom
R.J. Barlow, S. Rowan
IIAA, Huddersfield, United Kingdom

Due to the large stored beam energy in the HL-LHC new collimation technologies must be used to protect the machine. Active halo control of the proton beam halo with a Hollow Electron Lens can give a kick to protons at the edge of the beam without effecting the core. Various modes of operation are possible for example the electron lens can have a continuous current or it can be pulsed to different amplitudes for each passage of the proton beam. In this article we use Merlin++ simulations to show the performance of these modes for HL-LHC parameters. We also present recent simulations comparing scattering models in Merlin++.

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paper received ※ 08 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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MOPTS101

Study of the Transverse Emittance Blow-Up Along the Proton Synchrotron Booster Cycle During Wire Scanner Operation

emittance, simulation, proton, brightness

1110

A. Santamaría García, F. Antoniou, H. Bartosik, J.A. Briz Monago, G.P. Di Giovanni, A. Guerrero, J.R. Hunt, B. Mikulec, F. Roncarolo, E. Senes, V. Vlachoudis
CERN, Geneva, Switzerland
E. Senes
Oxford University, Physics Department, Oxford, Oxon, United Kingdom

Transverse emittance measurements with wire scanners have been extensively studied across the accelerator complex at CERN due to their important role in characterizing the beam and their complicated modeling. In recent years, this topic has been of particular interest for the LHC Injectors Upgrade (LIU) project, where a tight transverse emittance blow-up budget between the Proton Synchrotron Booster (PSB) and the Proton Synchrotron (PS) is imposed to assure the required beam brightness for the High Luminosity LHC (HL-LHC). In order to maintain a high brightness beam, any source of emittance blow-up along the PSB cycle needs to be identified and mitigated. While wire scanners have been mostly used at extraction energy in the PSB, they can also operate along the energy cycle. The scattering of the protons with the wire increases considerably at lower energies, leading to an overestimation of the beam emittance. In this contribution we present the most recent studies, focusing on precisely quantifying the blow-up created by the flying wire with measurements in an optimized set-up and compared to FLUKA simulations.

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paper received ※ 13 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

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TUPMP022

Research on Digital Scanning Power Supply Technology for Proton Therapy System

power-supply, proton, controls, radiation

1286

J. Huang, M. Fan, J. Yang, L.G. Zhang
HUST, Wuhan, People’s Republic of China
T. Yu, C. Zuo
Huazhong University of Science and Technology, State Key Laboratory of Advanced Electromagnetic Engineering and Technology,, Hubei, People’s Republic of China

Funding: Work supported by The National Key Research and Development Program of China, with grant No. 11505068
Proton has great advantages in the field of cancer radiotherapy because of its good characteristic of Bragg peak. HUST-PTF is a proton therapy facility under development in Huazhong University of science and technology. It delivers the beam to the patients with a pencil beam scanning nozzle. Scanning power supplies are placed in the nozzle of the proton therapy device and they are required high accuracy, high speed and high stability. In this paper，the structure diagram of HUST-PTF is shown. The parameters of scanning magnets and its power supply are introduced. Finally, some test results of power supply are shown. The next work will debug the control system of the scanning power supply and adjust it with the scanning magnet to see if it meets the design requirements.

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paper received ※ 19 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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TUPGW059

Studies of The Electron Beam Lifetime in Solaris Electron Storage Ring

electron, storage-ring, cavity, vacuum

1541

R. Panas, A.M. Marendziak, A.I. Wawrzyniak, M. Wisniowski
Solaris National Synchrotron Radiation Centre, Jagiellonian University, Kraków, Poland

Solaris storage ring is a recently constructed and commissioned machine operated in decay mode. With total accumulated beam dose near to 1000 A.h the measured total lifetime has reached 16 h for 270mA of a stored current. In this paper, the beam lifetime studies are presented using measured residual gas analysis and vertical scraper position for tuned and detuned Landau cavities. It shows that for stable beam the lifetime is dominated by the interaction of the electron with residual gas (vacuum lifetime) and between electrons interaction within a bunch (Touschek lifetime). The estimated vacuum, Touschek and total beam lifetimes from theoretical analysis are also compared with the measured beam lifetime.

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paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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TUPGW085

A Hard X-Ray Compact Compton Source at CBETA

electron, laser, photon, brilliance

1604

K.E. Deitrick, C. Franck, G.H. Hoffstaetter, V.O. Kostroun, K.W. Smolenski
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
J. Crone, H.L. Owen
UMAN, Manchester, United Kingdom
B.D. Muratori
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

Compton backscattering at energy recovery linacs (ERLs) promises high flux, high energy x-ray sources in the future, made possible by high quality, high repetition rate electron beams produced by ERLs. CBETA, the Cornell-BNL ERL Test Accelerator currently being built and commissioned at Cornell, is an SRF multi-turn ERL using Non-Scaling Fixed Field Alternating-gradient (NS-FFA) arcs. CBETA has high quality design parameters with an anticipated top energy of 150 MeV on the fourth pass. The expected parameters of a Compton source at CBETA include a top x-ray energy of over 400 keV with a flux on the order of 10¹² ph/s. In this paper, we present anticipated parameters and potential applications in science and engineering for this source.

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paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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TUPGW110

Improvement of Touschek Lifetime by Higher Harmonic RF Cavity in the SPS Storage Ring

cavity, storage-ring, operation, synchrotron

1669

T. Phimsen, N. Juntong, P. Sudmuang
SLRI, Nakhon Ratchasima, Thailand
B.C. Jiang
Shanghai Advanced Research Institute, Pudong, Shanghai, People’s Republic of China
Z.T. Zhao
SSRF, Shanghai, People’s Republic of China

Siam Photon Source (SPS), located at Nakhon Ratchasima, Thailand, is a synchrotron light source with the beam energy of 1.2 GeV. User operation is performed in beam decay mode with the maximum current of 150 mA. Beam lifetime is about 12 hours at the beam current of 100 mA. Beam injection is carried out twice a day, and even with full energy, it takes roughly 30 minutes. Beam lifetime in the SPS storage ring is limited by Touschek scattering and strongly depends on operation conditions. Higher harmonic RF cavity is a proven method to increase the beam lifetime and suppressing coupled bunch instabilities through Landau damping effect. If the beam lifetime is increased for examples, to be double, only one injection per day would be needed. In this study, an improvement of Touschek lifetime by passive harmonic RF cavity is investigated.

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paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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WEXXPLS2

Accelerator Vacuum Windows: A Review of Past Research and a Strategy for the Development of a New Design for Improved Safety and Longevity for Particle Accelerators

vacuum, Windows, radiation, experiment

2237

C.R. Ader, M.L. Alvarez, J.S. Batko, R. Campos, M.W. McGee, A.C. Watts
Fermilab, Batavia, Illinois, USA

Funding: Fermi National Accelerator Laboratory
Vacuum window research continues at Fermilab and this paper will examine cost effective, consistent designs which can have a significant impact on accelerator laboratories in terms of safety and cost. Issues such as the design, materials, analysis, testing and fabrication are addressed, including beam scattering and materials cost-benefit analysis and examining potential material substitutes for beryllium. A previous research paper has examined current fabrication and design techniques and also failure modes at Fermi, and this paper focuses on emerging and novel technologies for vacuum window fabrication. Many different paths have been taken by High Energy Physics (HEP) Laboratories throughout the world with varying success. The history of vacuum window development is extensive and not well defined, and a matrix of the research already completed on materials and joint design for vacuum windows will be shown. This report finally includes a treatise for vacuum window technology and a view towards emerging designs and materials and discusses future advances of research such as fabrication techniques including additive manufacturing and ultrasonic welding. Further exploration into these would prove beneficial to developing vacuum windows that are safer and stronger while being more transparent to the beam.

Slides WEXXPLS2 [3.139 MB]

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paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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WEPMP038

Combined MCNP/Turtle Simulation of the SINQ Beam Line at PSI-HIPA

simulation, target, proton, optics

2410

D. Reggiani, D.C. Kiselev, M. Seidel, V. Talanov, M. Wohlmuther
PSI, Villigen PSI, Switzerland

With a nominal beam power of nearly 1.4 MW, the PSI High Intensity Proton Accelerator (HIPA) complex is currently at the forefront of the high intensity frontier of particle accelerators. A key issue of such facilities is the minimization of beam losses that could lead to excessive activation of beam line components. At HIPA, the SINQ beam line is particularly subject to relatively large losses since it receives the highly divergent beam scattered off a 40 or 60 mm thick muon production graphite target (TE). So far, for HIPA, beam line simulations have been carried out only by means of the matrix multiplication codes TRANSPORT and TURTLE. Although very efficient, such tools do not allow a precise determination of beam losses whenever targets and collimators are substantially affecting the beam optics. A true understanding of how beam halo and the low momentum tail contribute to the measured losses can only be achieved by complementing the traditional simulations techniques by a tool that can transport beam particles in different materials and, at the same time, handle complex geometries like the ones of collimators situated in the beam line. Moreover, such an improved beam line simulation would give a significant contribution in evaluating the feasibility of the SINQ beam rotation system currently under study. In this paper we present a simulation of the SINQ beam line combining MCNP models of TE and collimator sections with the TURTLE computation of the magnetic channel.

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paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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WEPMP048

Development of Spin Rotator and an Absolute Polarimeter for Polarized He-3 at BNL

dipole, polarization, solenoid, target

2440

D. Raparia, G. Atoian, S. Ikeda, R.F. Lambiase, M. Okamura, A. Poblaguev, J. Ritter, S. Trabocchi, A. Zelenski
BNL, Upton, Long Island, New York, USA
R. Milner, M.M. Musgrave
MIT, Cambridge, Massachusetts, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
EBIS Preinjector will provide longitudinally polarized 3He++ ions with about 80% polarization and 5.10¹¹ particles per bunch at 6 MeV, which must be rotated to vertical direction before it ions are injected into the Booster. The 3He++ longitudinal polarization is first rotated to the transverse direction by the 21.5° bending magnet. Then the solenoid spin-rotator rotates the spin to the vertical direction. The spin-rotator will be a pulsed solenoid with a reversible field to enable spin flips. The vertically polarized beam will be returned back to the straight HEBT line by the system of three dipole magnets after the spin rotator solenoid. The low-energy polarimeter can be installed in the straight beam line section after the second dipole magnet. To measure transverse (vertical) polarization of the 3He beam at 5-6 MeV, the spin correlated asymmetry of 3He scattering on a 4He gas target (~5 Torr) will be measured with left/right symmetric strip detectors. Paper will present status of the project.

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paper received ※ 19 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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WEPGW106

Statistical Measurement of Longitudinal Beam Halo in Fermilab Recycler

experiment, detector, data-acquisition, booster

2742

E. Prebys, T.M. Nguyen
UCD, Davis, California, USA
A.S. Dyshkant, D. Hedin
Northern Illinois University, DeKalb, Illinois, USA
A. Gaponenko
Fermilab, Batavia, Illinois, USA
R.J. Hooper
Lewis University, Romeoville, Illinois, USA
M. Jones
Purdue University, West Lafayette, Indiana, USA

Funding: This work supported by US Department of Energy Contract DE-AC02-07CH11359
The formation of non-Gaussian halo in both the transverse and longitudinal dimensions of beam bunches has been notoriously difficult both the model and to measure. We present a technique to measure the longitudinal halo of 2.5 MHz bunches in the Fermilab Recycler, which have been formed for the g-2 anomalous magnetic moment experiment. While out of time beam is not a particular concern to this experiment, it is a key issue for the subsequent Mu2e rare muon decay experiment, which will use the same bunch formation procedure. Our measurement relies on a statistical technique, in which a small fraction of the beam is scattered from the primary collimation foil in the recycler, and then is detected by a charge telescope consisting of quartz Cherenkov radiators and photomultiplier tubes. By integrating over many revolutions, the time profile of longitudinal halo (out-of-time beam) can be measured down to less than a 10^-5 fractional level, relative to in-time beam. These results can then be compared to simulations.

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paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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WEPRB052

Design of Two Types of X-Band High Power Directional Coupler

GUI, coupling, simulation, operation

2928

G. Wang, X. Lin, Y.G. Tang, C.-F. Wu
USTC/NSRL, Hefei, Anhui, People’s Republic of China

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.

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paper received ※ 27 April 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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WEPTS002

Study of a Proton Therapy Beamline for Eye Treatment with Beam Delivery Simulation (BDSIM) and an In-House Tracking Code

simulation, proton, neutron, site

3088

E. Gnacadja, C. Hernalsteens, N. Pauly, R. Tesse
ULB - FSA - SMN, Bruxelles, Belgium
S.T. Boogert, L.J. Nevay, W. Shields
JAI, Egham, Surrey, United Kingdom

The complete modelling of passive scattering proton therapy systems is challenging and requires simulation tools that have capabilities in both beam transport and in the detailed description of particle-matter interactions. Beam Delivery Simulation (BDSIM) allows the seamless simulation of the transport of particles in a beamline and its surrounding environment. A complete 3D model can be built from Geant4, CLHEP and ROOT to provide a complete analysis of the primary beam tracking. This capability is applied to the eye treatment proton therapy machine part of the IBA Proteus Plus product line. Those simulations are compared with a fast in-house particle tracking code with a semi-analytical model of Multiple Coulomb Scattering. The preliminary results leading to the detailed knowledge of the beamline performance are discussed in detail.

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paper received ※ 15 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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WEPTS026

Generalised Scattering Module in SixTrack 5

target, lattice, experiment, proton

3156

K.N. Sjobak
University of Oslo, Oslo, Norway
H. Burkhardt, R. De Maria, V.K.B. Olsen
CERN, Geneva, Switzerland

Funding: Research Council of Norway, project 255196, and HL-LHC WP8
A generalised scattering module has recently been added to SixTrack. This module enables the use of arbitrary generators and target profiles. Presently, a simple model of elastic scattering and a coupling to Pythia8 have been implemented. This makes it possible to use SixTrack for studies of aperture losses and beam lifetime as a result of beam–beam scattering.

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paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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WEPTS043

SixTrack Version 5: Status and New Developments

simulation, electron, collimation, HOM

3200

R. De Maria, J. Andersson, L. Field, M. Giovannozzi, P.D. Hermes, N. Hoimyr, G. Iadarola, S. Kostoglou, E.H. Maclean, E. McIntosh, A. Mereghetti, J. Molson, V.K.B. Olsen, D. Pellegrini, T. Persson, M. Schwinzerl
CERN, Geneva, Switzerland
B. Dalena, T. Pugnat
CEA-IRFU, Gif-sur-Yvette, France
K.N. Sjobak
University of Oslo, Oslo, Norway
I. Zacharov
EPFL, Lausanne, Switzerland

SixTrack Version 5 is a major SixTrack release that introduces new features, with improved integration of the existing ones, and extensive code restructuring. New features include dynamic-memory management, scattering-routine integration, a new initial-condition module, and reviewed post-processing methods. Existing features like on-line aperture checking and Fluka-coupling are now enabled by default. Extensive performance regression tests have been developed and deployed as part of the new-release generation. The new features of the tracking environment developed for the massive numerical simulations will be discussed as well.

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THPGW035

Development of Yb-Based Laser System for Crab Crossing Laser-Compton Scattering

laser, electron, luminosity, experiment

3657

R. Morita, Y. Koshiba, S. Ota, M. Washio
Waseda University, Tokyo, Japan
T. Higashiguchi
Center for Optical Research and Education, Utsunomiya University, Utsunomiya, Japan
K. Sakaue
The University of Tokyo, The School of Engineering, Tokyo, Japan
J. Urakawa
KEK, Ibaraki, Japan

Funding: This work was supported by JSPS KAKENHI 18H0123.
We are going to demonstrate the principle of crab crossing in laser-Compton scattering which creates head-on collision in a pseudo manner to enhance the intensity of laser-Compton X-ray. When the electron beam is tilted by half of the collision angle, the scat-tered X-rays becomes the largest. Calculation shows that more than threefold luminosity will be achieved in our system and could be larger luminosity depending on the beam parameters. The intensity of scattered light can be efficiently enhanced by using a collision laser with high intensity, high quality and ultrashort pulse duration. Thus, we have introduced a regenera-tive amplifier using ceramics thin-disk as a collision laser and developed a dedicated laser system. In this conference, we will report on our laser system and results of crab crossing laser-Compton scattering.

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paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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THPGW039

Moderation of Positive Muons by Helium Gas

proton, experiment, simulation, vacuum

3667

Y. Li, Y. Bao, R. Fan, X. Li, X. Tong
IHEP, Beijing, People’s Republic of China
C.J. Ning, P.C. Wang
IHEP CSNS, Guangdong Province, People’s Republic of China

Funding: This work is supported by CAS, National Natural Science Foundation of China (Grant No. 11875281), and China Postdoctoral Science Foundation (Grant No. 2019M650845)
Efficiently creating beams of spin-polarized positive muons with energies between eV and keV (so-called slow muon beams) is important for further development and application of muon spin rotation, relaxation, and resonance techniques. One existing moderation method involves the use of wide-band-gap materials as moderators such as rare gas solids and solid nitrogen thin films (band-gap energy between 11 eV and 22 eV). Based on this moderation method, we have studied the use of helium gas as a moderator, with the goal of producing the slow muon beam more efficiently. Because of helium’s high (24.6 eV) ionization energy and because the cross section for muonium formation is suppressed in helium gas, we expect the production of slow muons using helium gas to be highly efficient.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW039

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paper received ※ 01 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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THPRB095

A Simulation Framework for Photon-Particle Interactions for Laserwires and Further Applications

laser, photon, electron, simulation

4045

S.E. Alden, S.M. Gibson, L.J. Nevay
JAI, Egham, Surrey, United Kingdom

A model has been developed for simulating photon-particle interactions with Beam Delivery Simulation (BDSIM). BDSIM is a high energy physics program that utilises the Geant4, CLHEP, and ROOT libraries to seamlessly track particles through an accelerator. The photon-particle interactions introduce the capability for modelling a range of applications in accelerator physics. One such application is a laserwire which is a minimally invasive diagnostic technique to measure beam profiles and emittance. In this paper we describe the recent implementation of inverse Compton scattering and electron stripping of Hydrogen ions. This is demonstrated on an example beamline.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB095

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paper received ※ 15 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019

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THPRB118

Study on the Influence of the Range Shifter Material in a Scanning Nozzle for Proton Therapy Based on Monte Carlo Method

proton, neutron, ECR, radiation

4100

Y.C. Yu, H.D. Guo, Y.Y. Hu, X.Y. Li, Y.J. Lin, P. Tan, X.D. Tu, L.G. Zhang
HUST, Wuhan, People’s Republic of China

Range shifter plays a key role in decreasing the energy of the proton beam to realize shallow tumours treatment with the scanning nozzle in Huazhong University of Science and Technology Proton Therapy Facility (HUST-PTF). To control the transverse scattering and decrease the damage to healthy tissue caused by secondary particle, influence of the range shifter material was studied. In this paper, the Monte Carlo software Geant4 and FLUKA are applied to analyse the transport process of proton beam in the range shifters made of six different materials: PMMA, Lexan, Lucite, Polyethylene, Polystyrene, and Wax. The beam spot sizes at the iso-center with or without range shifter was calculated for the HUST-PTF scanning nozzle. The relationship between the thickness of the range shifters of the six materials and the proton energy was obtained. The secondary neutron yield at the end of the nozzle was also analysed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB118

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paper received ※ 14 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

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