IPAC2013 - List of Keywords (shielding)

Paper	Title	Other Keywords	Page
MOPEA073	Current Status of the LBNE Neutrino Beam	target, proton, simulation, focusing	255
	C.D. Moore, K.R. Bourkland, C.F. Crowley, P. Hurh, J. Hylen, B.G. Lundberg, A. Marchionni, M.W. McGee, N.V. Mokhov, V. Papadimitriou, R.K. Plunkett, S.D. Reitzner, A.M. Stefanik, G. Velev, K.E. Williams, R.M. Zwaska Fermilab, Batavia, USA
	Funding: Work supported by the Fermilab Research Alliance, under contract DE-AC02-07CH11359 with the U.S. Dept of Energy. The Long Baseline Neutrino Experiment (LBNE) will utilize a neutrino beamline facility located at Fermilab. The facility is designed to aim a beam of neutrinos toward a detector placed in South Dakota. The neutrinos are produced in a three-step process. First, protons from the Main Injector hit a solid target and produce mesons. Then, the charged mesons are focused by a set of focusing horns into the decay pipe, towards the far detector. Finally, the mesons that enter the decay pipe decay into neutrinos. The parameters of the facility were determined by an amalgam of the physics goals, the Monte Carlo modeling of the facility, and the experience gained by operating the NuMI facility at Fermilab. The initial beam power is expected to be ~700 kW, however some of the parameters were chosen to be able to deal with a beam power of 2.3 MW. The LBNE Neutrino Beam has made significant changes to the initial design through consideration of numerous Value Engineering proposals and the current design is described.

MOPME013	20 Years of Development of SQUID-based Cryogenic Current Comparator for Beam Diagnostics	pick-up, ion, cryogenics, niobium	497
	W. Vodel HIJ, Jena, Germany R. Geithner, R. Neubert, P. Seidel FSU Jena, Jena, Germany K.K. Knaack, K. Wittenburg DESY, Hamburg, Germany A. Peters HIT, Heidelberg, Germany H. Reeg, M. Schwickert GSI, Darmstadt, Germany
	This contribution gives an overview on the development of highly sensitive SQUID-based Cryogenic Current Comparators (CCC) for nuclear physics from the first successful demonstration of its performance at GSI Darmstadt through the latest improved version for FAIR and the Cryogenic Storage Ring at MPI Heidelberg. An absolute and exact measurement of the intensity of charged particle beams - extracted from an accelerator or circulating in a Storage Ring - is one of the major problems of beam diagnosis. Also the measurement of so-called dark currents, generated by super-conductive RF accelerator cavities at high voltage gradients to characterize the quality of these components becomes more and more important for the commissioning of new accelerators (XFEL at DESY). The Cryogenic Current Comparator (CCC) based on high precision LTS SQUIDs is an excellent tool to solve these problems.

MOPWA065	Affordable, Short Pulse MARX Modulator	controls, high-voltage, linear-collider, collider	828
	R.A. Phillips, M.P.J. Gaudreau, M.K. Kempkes, B.E. Simpson Diversified Technologies, Inc., Bedford, Massachusetts, USA J.A. Casey Rockfield Research Inc., Las Vegas, Nevada, USA
	Under a U.S. Department of Energy grant, Diversified Technologies, Inc. (DTI) is developing a short pulse, solid-state Marx modulator for the next generation of klystrons and accelerators. For short-pulse modulators, this Marx topology provides a means to achieve astounding risetimes and flattop control that are simply not available with hard switch or transformer coupled topologies. The design is a high peak-power pulse modulator of greater efficiency than presently available, in the 100 kV to 1 MV range, for currents of 0.1 to 1 kA, pulse lengths of 0.2 to 5.0 us, and rise/fall times 10% of pulse length. A key objective of the development effort is a design which is modular and scalable, yet low cost, and easy to manufacture and maintain. The modulator will be delivered to Yale Beam Physics Laboratory for evaluation, and will be affordable for deployment at other national labs for klystron and modulator evaluation. In this paper, DTI will describe the new design and provide an update on progress.

MOPWO088	Semi-analytical Description of the Modulator Section of the Coherent Electron Cooling	electron, plasma, hadron, simulation	1082
	A. Elizarov, V. Litvinenko BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. We discuss the theoretical description of the modulator section of the coherent electron cooling (CeC), the modern realization of the stochastic electron cooling, where the electron beam serves as a modulator and a kicker, i.e., it records the information about the hadron beam via electron density perturbations resulting from the shielding of the hadrons and then accelerates or decelerates hadrons by its electric field with respect to their velocities. To analyze the performance of the CeC shielding of a hadron in an electron beam should be computed with high precision. We propose a solution of this problem via Fourier and Laplace transforms for 1D, 2D and 3D plasmas. In some cases there are fully analytical solutions, which gave an opportunity to test semi-analytical ones involving numerical evaluations of the inverse integral transforms. Having its own practical value this solution will also serve as a testing ground for our general solution via numerical treatment of the integral equations applicable for the realistic case of the finite beam. V. N. Litvinenko, Y. S. Derbenev, Phys. Rev. Lett. 102, 114801 (2009). ** A. Elizarov, V. Litvinenko, G. Wang, IPAC'12 Proceedings, weppr099 (2012).

TUPFI021	FLUKA Energy Deposition Studies for the HL-LHC	luminosity, quadrupole, radiation, optics	1379
	L.S. Esposito, F. Cerutti, E. Todesco CERN, Geneva, Switzerland
	The LHC upgrade, planned in about ten years from now, is envisaged to accumulate up to 3000 fb-1 integrated luminosity by running at a peak luminosity of 5 x 10³⁴ cm^-2 s⁻¹. In order to reach such an ambitious goal, the high luminosity insertions need a major redesign implying a 150 mm aperture low-beta Inner Triplet, a superconducting D1 and new quadrupoles in the Matching Section. Energy deposition studies show that degradation of the coil insulator represents the most challenging issue from the radiation impact point of view. We propose a suitable shielding consisting of a beam screen with several mm tungsten absorbers at mid-planes to guarantee not to exceed a few ten MGys. This will also allow a good margin with respect to the risk of radiation induced quenches. O. Brüning, L. Rossi, "High Luminosity Large Hadron Collider: A description for the European Strategy Preparatory Group," CERN ATS 2012-236.*

TUPFI054	MICE Spectrometer Solenoid Magnetic Field Measurements	solenoid, emittance, simulation, factory	1466
	M.A. Leonova Fermilab, Batavia, USA
	The Muon Ionisation Cooling Experiment (MICE) is designed to demonstrate ionization cooling in a muon beam. Its goal is to measure a 10% change in transverse emittance of a muon beam going through a prototype Neutrino Factory cooling channel section with a 1% accuracy, corresponding to an absolute measurement accuracy of 0.1%. To measure the emittance, MICE uses two solenoidal spectrometers. The Spectrometer Solenoids are designed to have 4 T solenoidal fields, uniform at 3 per mil level in the tracking volumes. Analysis of magnetic field measurements of the Spectrometer Solenoids will be discussed, and results of extracting precise coil positions, angles, and coil radius measurements for input into magnet models will be presented.

TUPFI067	Energy Deposition and Shielding Study of the Front End for the Neutrino Factory	proton, target, solenoid, factory	1505
	P. Snopok IIT, Chicago, Illinois, USA D.V. Neuffer Fermilab, Batavia, USA C.T. Rogers STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
	In the Neutrino Factory and Muon Collider muons are produced by firing high energy protons onto a target to produce pions. The pions decay to muons which are then accelerated. This method of pion production results in significant background from protons and electrons, which may result in heat deposition on superconducting materials and activation of the machine preventing manual handling. In this paper we discuss the design of a secondary particle handling system. The system comprises a solenoidal chicane that filters high momentum particles, followed by a proton absorber that reduces the energy of all particles, resulting in the rejection of low energy protons that pass through the solenoid chicane. We detail the design and optimization of the system, its integration with the rest of the muon front end, and energy deposition and shielding analysis in MARS15.

TUPWA030	Impedances Calculations of Bellows in HLS II Storage Ring	impedance, wakefield, storage-ring, coupling	1784
	Q. Zhang, W. Li, L. Wang USTC/NSRL, Hefei, Anhui, People's Republic of China
	The upgrade project of Hefei Lighe Source storage ring is carrying on.In this project,a new Bellows, in which shielding is provided by sprung fingers which can slide along the beam screen,is installed at the accelerator interaction area In order to reduce this impedance to an acceptable value. The contributions of Bellows to short range wakefields and broadband impedance were calculated numerically by Mafia code .

WEPWA015	Progress in Construction of the 35 MeV Compact Energy Recovery Linac at KEK	linac, gun, cryomodule, laser	2159
	S. Sakanaka, S. Adachi, M. Akemoto, D.A. Arakawa, S. Asaoka, K. Enami, K. Endo, S. Fukuda, T. Furuya, K. Haga, K. Hara, K. Harada, T. Honda, Y. Honda, H. Honma, T. Honma, K. Hosoyama, K. Hozumi, E. Kako, Y. Kamiya, H. Katagiri, H. Kawata, Y. Kobayashi, Y. Kojima, Y. Kondou, T. Kume, T. Matsumoto, H. Matsumura, H. Matsushita, S. Michizono, T. Miura, T. Miyajima, S. Nagahashi, H. Nakai, H. Nakajima, N. Nakamura, K. Nakanishi, K. Nakao, K.N. Nigorikawa, T. Nogami, S. Noguchi, S. Nozawa, T. Obina, T. Ozaki, F. Qiu, H. Sagehashi, H. Sakai, S. Sasaki, K. Satoh, M. Satoh, T. Shidara, M. Shimada, K. Shinoe, T. Shioya, T. Shishido, M. Tadano, T. Takahashi, R. Takai, T. Takenaka, Y. Tanimoto, M. Tobiyama, K. Tsuchiya, T. Uchiyama, A. Ueda, K. Umemori, K. Watanabe, M. Yamamoto, Y. Yamamoto, Y. Yano, M. Yoshida KEK, Ibaraki, Japan E. Cenni Sokendai, Ibaraki, Japan R. Hajima, S.M. Matsuba, R. Nagai, N. Nishimori, M. Sawamura, T. Shizuma JAEA, Ibaraki-ken, Japan H. Takaki ISSP/SRL, Chiba, Japan
	The 35-MeV Compact Energy Recovery Linac (the Compact ERL or cERL) is under construction at the High Energy Accelerator Research Organization (KEK) in Japan. With the Compact ERL, we aim at establishing cutting-edge technologies for the GeV-class ERL-based synchrotron light source. To install the accelerator components of the cERL, we have constructed a shielding room having an area of about 60 m x 20 m. We have then installed a 500-kV DC photocathode gun, a 5-MV superconducting (SC) cryomodule for the injector, a 30-MV SC cryomodule for the main linac, and some of the other components. High-power test on the main SC cryomodule is underway in December, 2012. High-power or high-voltage tests on the injector cryomodule and on the DC gun are planned during January to March, 2013. An injector of the Compact ERL will be commissioned in April, 2013. We report the newest status of its construction.

WEPWO011	In-vacuum Temperature Measurement of Niobium Components using Infrared Pyrometry during Electron Beam Welding Procedure	cavity, vacuum, electron, controls	2334
	L. Monaco, P. Michelato, C. Pagani, D. Sertore INFN/LASA, Segrate (MI), Italy V. Battista, G. Corniani, M. Festa Ettore Zanon S.p.A., Schio, Italy
	Electron beam welding (EBW) is widely used in the construction of Niobium Superconducting RF cavities. The welding sequence of such a complex structure, foresees many welding operations. The welding parameters depend on many variables as the material thickness, but also on the component temperature before each weld. This paper presents a technique to measure the temperature of Nb components in vacuum during the EBW operation using an IR pyrometer placed outside the vacuum chamber through an appropriate vacuum viewport. With the current configuration the system can measure temperatures up to 350°C in the vacuum conditions of the EBW vacuum chamber (10-5-10^-6 mbar). The technique was used to optimize the time interval between each subsequent equatorial weld operation during Nb cavities production at Ettore Zanon, increasing the welding procedure reliability and decreasing the waiting time by control of the temperatures in the weld region. Moreover this technique can be generally used for in vacuum measurements of components from room temperature up to about 350 °C. Future developments are under way to make this technique compatible with UHV and increasing the measurement range.

WEPEA041	Actions To Mitigate The Radiation Damage to Electronics at the LHC	radiation, hadron, controls, civil-engineering	2591
	A.-L. Perrot, M.B.M. Barberan Marin, J.-P. Corso, K. Foraz, M. Lazzaroni, Y. Muttoni CERN, Geneva, Switzerland
	The level of flux of hadrons with energy in the multi MeV range expected from the collisions at the LHC interaction Points 1, 5 and 8 and from the collimation system at Point 7 will induce Single Event Errors (SEEs) in the standard electronics present in many of the control equipment installed in LHC underground. Furthermore, a risk of SEEs induced by thermal neutrons cannot be excluded. Such events would perturb the LHC operation, possibly leading to a stop of the machine. Main mitigation actions will be implemented during the first LHC Long Shutdown of 2013/2014 (LS1) to reduce the SEE occurrence. This paper summarizes the mitigation measures and their associated foreseen improvements in terms of SEEs. It presents the organization process and associated planning highlighting the impacts with the overall LHC LS1 planning and the main concerns during implementation.

WEPEA057	Numerical Simulations to Evaluate the Performance of CERN PS Dummy Septum to Reduce Irradiation for the Multi-Turn Extraction	septum, extraction, kicker, beam-losses	2636
	C. Hernalsteens, S. Damjanovic, S.S. Gilardoni, M. Giovannozzi CERN, Geneva, Switzerland
	The losses created by the proposed Multi-Turn Extraction (MTE) at the CERN PS induces high activation of the magnetic extraction septum due to the de-bunched longitudinal beam structure requested to transfer the beam to the SPS. A mitigation measure is under study aiming at localizing losses in a well-shielded area by shadowing the magnetic extraction septum thanks to septum-like passive device. Such a solution is based on a so-called dummy septum, a blade which absorbs particles during the rise time of the extraction kickers for MTE beams. The efficiency of the scheme is presented in this paper. The quantitative estimate is based on detailed simulations that analyse the beam-matter interaction and provide a determination of the shadowing effect of the dummy septum.

WEPFI067	FETS RF System Design and Circulator Testing	rfq, klystron, ion, insertion	2851
	S.M.H. Alsari, J.K. Pozimski, P. Savage Imperial College of Science and Technology, Department of Physics, London, United Kingdom M. Dudman, A.P. Letchford STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
	The Front End Test Stand (FETS) is an experiment based at the Rutherford Appleton Laboratory (RAL) in the UK. In this experiment, the first stages necessary to produce a very high quality, chopped H⁻ ion beam as required for the next generation of high power proton accelerators (HPPAs) are designed, built and tested. HPPAs with beam powers in the megawatt range have many possible applications including drivers for spallation neutron sources, neutrino factories, accelerator driven sub-critical systems, waste transmuters and tritium production facilities. RF system outline and design options of the waveguide and coaxial parts and shielding are presented and discussed in this paper. Experimental measurements of the system’s circulator will be presented as part of the system testing results.

THOAB201	Development of the Dielectric Wall Accelerator	proton, dipole, simulation, radiation	3115
	A. Zografos, T. Brown, C. Cohen-Jonathan, C. Hettler, F. Huang, V. Joshkin, K. Leung, M. Moyers, Y.K. Parker, D. Pearson, M. Rougieri CPAC, Livermore, CA, USA R.W. Hamm R&M Technical Enterprises, Pleasanton, California, USA
	The Compact Particle Accelerator Corporation has developed an architecture to produce pulsed proton bunches that will be suitable for proton beam therapy. The Dielectric Wall Accelerator engineering prototype includes a RFQ injection system with a pulsed kicker to select the desired proton bunches and a linear accelerator incorporating a High Gradient Insulator with stacked transmission to produce the required voltage. The transmission lines are switched with solid state laser driven optical switches. A computational model has been developed that is in very good agreement with the experimental results. The system is presently achieving accelerating gradients of approximately 15 MeV/m. The computational model has been used to design the next generation system that will achieve 25 MeV/m by early 2013. This paper will discuss the status of the apparatus, the basic elements of the computational model, experimental results and comparison to the model predictions. In addition, the paper will present concepts for proton therapy systems that incorporate the Dielectric Wall Accelerator and fully leverage its features to achieve clinical requirements.
	Slides THOAB201 [1.650 MB]

THOBB201	Pathway to a Post Processing Increase in Q0 of SRF Cavities	cavity, niobium, SRF, cryogenics	3129
	O. Kugeler, J. Knobloch, J.M. Vogt HZB, Berlin, Germany S. Aull CERN, Geneva, Switzerland
	A significant improvement of Q0 to values larger than 3.2x10¹⁰ at 1.8K has been repeatedly achieved in an SRF cavity by thermal cycling, i.e. heating the cavity briefly above transition temperature and subsequent cooling. Conceivable explanations for this effect reach from effectivity deviations of the magnetic shielding to thermal currents to hydrogen diffusion. Experimental We have experimentally verified some of these explanations, leaving a direct impact of cooling dynamics on frozen flux as the most plausible one. The pathway to this finding is being presented and the application to SRF systems is elicited.
	Slides THOBB201 [1.184 MB]

THPEA027	Radiation Calculations for Advanced Proton Therapy Facility	proton, radiation, simulation, target	3201
	J.Q. Xu, J.J. Lu, G. Wang, X. Xia SINAP, Shanghai, People's Republic of China
	The shielding calculations for Advanced Proton Therapy Facility (APTRON), which is under design in Shanghai, were carried out. The thickness of radiation shielding walls for the accelerator and treatment rooms of APTRON were determined by Monte Carlo simulation and empirical formula. Beam loss scenarios and workloads of different energy at LINAC, synchrotron, beam transport line and treatment are given for the calculations. The calculations were carried out for the proton energy of 150MeV, 220MeV and 250MeV, and the targets of iron and equivalent tissue material. Source terms and attenuation length were calculated with different angles by the simulation using FLUKA code. Based on the source terms and the attenuation length, the thickness of the bulk walls were determined. Local shielding and maze design were also concerned.

THPEA039	Radiation Protection Study for the Shielding Design of the LINAC 4 Beam Dump at CERN	linac, radiation, neutron, simulation	3225
	J. Blaha, J. Vollaire CERN, Geneva, Switzerland
	Linac4, a new 160 MeV H⁻ accelerator, is currently being constructed at CERN. The accelerator is terminated by a dump collecting beam which is not intended for further utilization. The aim of this study is to determine an optimal shielding of the beam dump fulfilling the radio-protection requirements. The proposed shielding must take into account different accelerator operational phases, the space constraints inside the accelerator vault as well as the decommissioning of the installation at the end of its lifetime. Therefore a detailed Monte-Carlo calculation using FLUKA particle transport and interaction code has been performed and the relevant physics quantities have been evaluated for different irradiation profiles and shielding material. Moreover, the residual dose rate and induced activation have been calculated for several cooling times in order to optimize the choice of the shielding material following the ALARA principle. Finally the airborne radioactivity induced by particles escaping the shielding as well as the activation of the beam dump cooling water have been also calculated using FLUKA and simplified laminar flow models.

THPFI015	In-situ Degassing of the Ferrite Cores in the Extraction Kicker Magnets of the J-PARC 3-GeV RCS	vacuum, kicker, target, quadrupole	3324
	J. Kamiya, Y. Hikichi, M. Kinsho, M. Nishikawa, N. Ogiwara, K. Suganuma, T. Yanagibashi JAEA/J-PARC, Tokai-mura, Japan
	Kicker magnets extract the accelerated beam to the beam transport lines in the RCS of the J-PARC. The kicker magnets mainly consist of Ni-Zn ferrite cores and Al alloy plates, and are installed in a vacuum to prevent discharge because a high voltage is applied for a short period. It is important to reduce the outgassing of water vapor from the ferrite cores. Although the kicker magnets have been working well, recently the vacuum quality became a little poor. Thus, we developed the in-situ degassing method for the ferrite cores. This is achieved by directing the heat from the heat source to the kicker magnet and not to the chamber wall. With the test stand we succeeded to flow almost all the heat toward the kicker magnet and to bake out the ferrite cores about 150°C, maintaining the temperature of the chamber wall less than 50°C. As the previous work with TDS measurements revealed that the absorbed water molecules can be easily removed by the bake-out at 100-150°C in a vacuum, the outgassing from the ferrite cores was successfully reduced. The details of the in-situ degassing method will be reported, including the practical method to reduce the outgassing of the working kickers.

THPFI020	Radiation Shielding Design for Medical Cyclotrons	cyclotron, proton, target, radiation	3339
	F. Wang, T. Cui, X.L. Jia, Z.G. Li, T.J. Zhang, X.Z. Zhang CIAE, Beijing, People's Republic of China
	With the increasing applications of cyclotrons in health care, a number of cyclotrons ranging from several MeVs to hundreds MeVs have used for radio diagnostic and radiation therapy. A 14 MeV PET cyclotron, CYCIAE-14, has been installed in a shielding building for tests at CIAE that can be used for FDG production and boron neutron capture therapy (BNCT). In the mean time, the development of a 235MeV cyclotron, CYCIAE-235, which can be used for proton therapy, is in progress at the same laboratory. In terms of the cyclotron application in factories and hospitals, an appropriate radiation shielding design is of critical importance. In the case of CYCIAE-14 and CYCIAE-235, the neutron source of different cyclotrons has been estimated to define the thickness of the total shielding, and the concrete is selected as the main shielding material. For CYCIAE-14 specifically, local shielding has been implemented. This paper will give an introduction to the radiation shielding design for CYCIAE-14 and CYCIAE-235 respectively. The typical layout for the application of the two machines is presented in this paper which can be applied in factories and hospitals as well.

THPFI027	STUDY ON STRUCTURE AND THERMAL ANALYSIS OF CSNS R BEAM DUMP	controls, neutron, proton, target	3356
	L. Liu, L. Kang, X.J. Nie, H. Qu IHEP, Beijing, People's Republic of China
	The China Spallation Neutron Source (CSNS) accelerator systems will provide a 1.6 Gev proton beam to a target for neutron production. Beam dump system is an important part of CSNS, and it is used to incept the waste beam. The beam dump system is composed with vacuum part and shielding part. For the design of shielding part, the material is steel at the centre and concrete outside, we must control the temperature of steel and concrete not too high, and it will be a serious problem that the concrete crazes because of the high temperature. So the thermal analyses must be done to ensure safety. Taking CSNS R dump for example, we use software to make model and analyze the thermal, then optimizing the result. According to the result, we control the work time and dimension of the beam to control the temperature of the iron and concrete. This article expatiate the study on the structure design and thermal analyses.

THPFI031	Development of Beam Collimators for the 1.6 GeV Rapid Cycling Synchrotron of CSNS	collimation, vacuum, synchrotron, simulation	3364
	J.B. Yu, pf.He. He, L. Kang, H. Qu, Y.Q. Zou IHEP, Beijing, People's Republic of China
	In order to reduce the uncontrolled losses in the localized station, the beam collimation system has been performed for the 1.6GeV synchrotron of CSNS. The CSNS/RCS transverse collimation system is designed to be a two-stage system which consists of one primary collimator and four secondary collimators. Much work about machinery design and manufacture of the collimation system has been done till now. This paper will show the exterior frame of collimation system by considering the physical demands and spatial position. Then the progress which contains design and machining of collimators will also be introduced. Finally some problems which are mainly about the design of secondary collimators will be mentioned.

THPFI062	Design of Air-cooled Beam Dump for Extraction Line of PS Booster	simulation, booster, cavity, proton	3436
	A. Perillo-Marcone, T. Antonakakis, M. Battistin, M.A. Czapski, G.W. Mason, E.M. Nowak, A. Sarrió Martínez, S. Sgobba, V. Venturi, V. Vlachoudis CERN, Geneva, Switzerland
	A new beam dump has been designed, which withstands the future proton beam extracted from the PS Booster at CERN, consisting of up to 10¹⁴ protons per pulse at 2 GeV after its upgrade in 2018/2019. In order to be able to efficiently release the deposited heat, the new dump will be made out of a single cylindrical block of a copper alloy and be cooled by forced ventilation. In order to determine the energy density distribution deposited by the beam in the dump, Monte Carlo simulations were performed using FLUKA, and thermo-mechanical analyses carried out by importing the energy density into Ansys. In addition, CFD simulations of the airflow were carried out in order to accurately estimate the heat transfer convection coefficient on the surface of the dump. In this paper we describe the design process and highlight the constraints of integrating a new dump for increased beam power into the existing facility.

THPFI067	The Mechanical Design, Fabrication, and Performance of the DCCT for TPS	vacuum, storage-ring, electron, high-voltage	3451
	C.-C. Chang, C.K. Chan, J.-R. Chen, G.-Y. Hsiung, H.P. Hsueh NSRRC, Hsinchu, Taiwan J.-R. Chen National Tsing Hua University, Hsinchu, Taiwan
	This paper describes the DC current transformers (DCCT), designed and fabricated for Taiwan Photon Source (TPS); including the mechanical structure, dissimilar material welding process for the DCCT chamber, electronically and vacuum performance testing. In the structure, a ceramic break disc is provided and jointed between to ends of the beam duct. The electrical connection path is interrupted in the beam duct adjacent to the transformer. To avoid the sensor measured the wall current and other unnecessary circulating currents. The DCCT toroid is independent installed outside of a vacuum beam duct to measure the average beam current. In order to reduce the influence of external magnetic field for the sensor, two layers of Mu metal shell are installed. The performance and progress for the DCCT are described in this paper.

THPFI092	Design of the Mercury Handling System for a Muon Collider/Neutrino Factory Target	target, collider, factory, proton	3505
	K.T. McDonald PU, Princeton, New Jersey, USA J.S. Berg, H.G. Kirk, H. K. Sayed BNL, Upton, Long Island, New York, USA X.P. Ding UCLA, Los Angeles, California, USA V.B. Graves ORNL, Oak Ridge, Tennessee, USA N. Souchlas, R.J. Weggel Particle Beam Lasers, Inc., Northridge, California, USA
	The baseline target concept for a Muon Collider or Neutrino Factory is a free mercury jet within a 20-T magnetic field being impacted by an 8-GeV proton beam. A pool of mercury serves as a receiving reservoir for the mercury and a dump for the unexpended proton beam. Modifications to this baseline are discussed in which the field at the target is reduced from 20 to 15 T, and in which the magnetic field drops from its peak value down to 1.5 T over 7 rather than 15 m.

THPME010	Magnetic Shielding for the 1.3 GHz Cryomodule at IHEP	simulation, cavity, SRF, cryomodule	3528
	S. Jin, Y. Chen, J. Gao, R. Ge, Y. Liu, Z.C. Liu, J.Y. Zhai, T.X. Zhao, H.J. Zheng IHEP, Beijing, People's Republic of China F. Yang China Iron and Steel Research Institute Group, Beijing, People's Republic of China
	An ILC-type Superconducting RF (SRF) accelerating unit is being studied at IHEP. In order to achieve the design performance including both accelerating gradient and quality factor, the SRF cavity must be cooled with ambient magnetic field well shielded to the level of several mG[1,2]. In this paper, permeability of several kinds of materials for magnetic shielding made in China is systematically studied in cooperation with China Iron & Steel Research Institute Group (CISRI) and reported for the first time. By using proper material, numerical calculation for the magnetic shielding design was done via the program of Opera-3D, and then magnetic shield was fabricated by CISRI. This paper will show those studies above and the final magnetic shielding effect at room temperature. Comparisons between simulation result and real effect will also be discussed in the paper, as well as the preliminary analysis for the magnetic field leaking of this design.

THPWO020	Simulations on the Boundary Fields of 4-rod RFQ Electrodes	rfq, simulation, cavity, quadrupole	3803
	J.S. Schmidt, B. Koubek, A. Schempp IAP, Frankfurt am Main, Germany
	If the RF design of a 4-rod Radio Frequency Quadrupole (RFQ) is not performed carefully with respect to the boundary fields of its electrodes, it can produce errors compared to beam dynamic simulations. An additional field component can be induced on the beam axis, which influences the properties of the particle beam, like energy per nucleon for example, dramatically. Therefore, the influences of different geometric parameters of 4-rod RFQs on these fields have been studied in detail. The results of these simulations will be presented in this paper.

THPWO085	Numerical and Experimental Study for the Characterization of the Spallation Target Performance of the Ultracold Neutron Source at the Paul Scherrer Institut	neutron, target, simulation, proton	3960
	V. Talanov, M. Wohlmuther PSI, Villigen PSI, Switzerland
	Results of numerical calculation and experimental characterization of the neutron flux profile in the vicinity of the ultracold neutron source (UCN) at the Paul Scherrer Institut (PSI) are presented. At first, the MCNPX-based model of the Monte-Carlo simulation with its detailed description of the so-called ‘Cannelloni’-type spallation target assembly and the realistic proton beam profile modeling is described. Thereafter the experimental determination of the thermal neutron flux profile using the gold foil activation, along the height of the UCN vacuum tank, starting from the proton beam plane, is presented. Both calculations and measurements were performed for the standard operation mode, with several seconds of the full proton beam on the target. Finally, a comparison of simulation and experimental results is discussed.

Paper

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MOPEA073

Current Status of the LBNE Neutrino Beam

target, proton, simulation, focusing

255

C.D. Moore, K.R. Bourkland, C.F. Crowley, P. Hurh, J. Hylen, B.G. Lundberg, A. Marchionni, M.W. McGee, N.V. Mokhov, V. Papadimitriou, R.K. Plunkett, S.D. Reitzner, A.M. Stefanik, G. Velev, K.E. Williams, R.M. Zwaska
Fermilab, Batavia, USA

Funding: Work supported by the Fermilab Research Alliance, under contract DE-AC02-07CH11359 with the U.S. Dept of Energy.
The Long Baseline Neutrino Experiment (LBNE) will utilize a neutrino beamline facility located at Fermilab. The facility is designed to aim a beam of neutrinos toward a detector placed in South Dakota. The neutrinos are produced in a three-step process. First, protons from the Main Injector hit a solid target and produce mesons. Then, the charged mesons are focused by a set of focusing horns into the decay pipe, towards the far detector. Finally, the mesons that enter the decay pipe decay into neutrinos. The parameters of the facility were determined by an amalgam of the physics goals, the Monte Carlo modeling of the facility, and the experience gained by operating the NuMI facility at Fermilab. The initial beam power is expected to be ~700 kW, however some of the parameters were chosen to be able to deal with a beam power of 2.3 MW. The LBNE Neutrino Beam has made significant changes to the initial design through consideration of numerous Value Engineering proposals and the current design is described.

MOPME013

20 Years of Development of SQUID-based Cryogenic Current Comparator for Beam Diagnostics

pick-up, ion, cryogenics, niobium

497

W. Vodel
HIJ, Jena, Germany
R. Geithner, R. Neubert, P. Seidel
FSU Jena, Jena, Germany
K.K. Knaack, K. Wittenburg
DESY, Hamburg, Germany
A. Peters
HIT, Heidelberg, Germany
H. Reeg, M. Schwickert
GSI, Darmstadt, Germany

This contribution gives an overview on the development of highly sensitive SQUID-based Cryogenic Current Comparators (CCC) for nuclear physics from the first successful demonstration of its performance at GSI Darmstadt through the latest improved version for FAIR and the Cryogenic Storage Ring at MPI Heidelberg. An absolute and exact measurement of the intensity of charged particle beams - extracted from an accelerator or circulating in a Storage Ring - is one of the major problems of beam diagnosis. Also the measurement of so-called dark currents, generated by super-conductive RF accelerator cavities at high voltage gradients to characterize the quality of these components becomes more and more important for the commissioning of new accelerators (XFEL at DESY). The Cryogenic Current Comparator (CCC) based on high precision LTS SQUIDs is an excellent tool to solve these problems.

MOPWA065

Affordable, Short Pulse MARX Modulator

controls, high-voltage, linear-collider, collider

828

R.A. Phillips, M.P.J. Gaudreau, M.K. Kempkes, B.E. Simpson
Diversified Technologies, Inc., Bedford, Massachusetts, USA
J.A. Casey
Rockfield Research Inc., Las Vegas, Nevada, USA

Under a U.S. Department of Energy grant, Diversified Technologies, Inc. (DTI) is developing a short pulse, solid-state Marx modulator for the next generation of klystrons and accelerators. For short-pulse modulators, this Marx topology provides a means to achieve astounding risetimes and flattop control that are simply not available with hard switch or transformer coupled topologies. The design is a high peak-power pulse modulator of greater efficiency than presently available, in the 100 kV to 1 MV range, for currents of 0.1 to 1 kA, pulse lengths of 0.2 to 5.0 us, and rise/fall times 10% of pulse length. A key objective of the development effort is a design which is modular and scalable, yet low cost, and easy to manufacture and maintain. The modulator will be delivered to Yale Beam Physics Laboratory for evaluation, and will be affordable for deployment at other national labs for klystron and modulator evaluation. In this paper, DTI will describe the new design and provide an update on progress.

MOPWO088

Semi-analytical Description of the Modulator Section of the Coherent Electron Cooling

electron, plasma, hadron, simulation

1082

A. Elizarov, V. Litvinenko
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
We discuss the theoretical description of the modulator section of the coherent electron cooling (CeC)*, the modern realization of the stochastic electron cooling, where the electron beam serves as a modulator and a kicker, i.e., it records the information about the hadron beam via electron density perturbations resulting from the shielding of the hadrons and then accelerates or decelerates hadrons by its electric field with respect to their velocities. To analyze the performance of the CeC shielding of a hadron in an electron beam should be computed with high precision. We propose a solution of this problem via Fourier and Laplace transforms for 1D, 2D and 3D plasmas. In some cases there are fully analytical solutions, which gave an opportunity to test semi-analytical ones involving numerical evaluations of the inverse integral transforms. Having its own practical value this solution will also serve as a testing ground for our general solution via numerical treatment of the integral equations applicable for the realistic case of the finite beam**.
* V. N. Litvinenko, Y. S. Derbenev, Phys. Rev. Lett. 102, 114801 (2009).
** A. Elizarov, V. Litvinenko, G. Wang, IPAC'12 Proceedings, weppr099 (2012).

TUPFI021

FLUKA Energy Deposition Studies for the HL-LHC

luminosity, quadrupole, radiation, optics

1379

L.S. Esposito, F. Cerutti, E. Todesco
CERN, Geneva, Switzerland

The LHC upgrade, planned in about ten years from now, is envisaged to accumulate up to 3000 fb-1 integrated luminosity by running at a peak luminosity of 5 x 10³⁴ cm^-2 s⁻¹*. In order to reach such an ambitious goal, the high luminosity insertions need a major redesign implying a 150 mm aperture low-beta Inner Triplet, a superconducting D1 and new quadrupoles in the Matching Section. Energy deposition studies show that degradation of the coil insulator represents the most challenging issue from the radiation impact point of view. We propose a suitable shielding consisting of a beam screen with several mm tungsten absorbers at mid-planes to guarantee not to exceed a few ten MGys. This will also allow a good margin with respect to the risk of radiation induced quenches.
O. Brüning, L. Rossi, "High Luminosity Large Hadron Collider: A description for the European Strategy Preparatory Group," CERN ATS 2012-236.

TUPFI054

MICE Spectrometer Solenoid Magnetic Field Measurements

solenoid, emittance, simulation, factory

1466

M.A. Leonova
Fermilab, Batavia, USA

The Muon Ionisation Cooling Experiment (MICE) is designed to demonstrate ionization cooling in a muon beam. Its goal is to measure a 10% change in transverse emittance of a muon beam going through a prototype Neutrino Factory cooling channel section with a 1% accuracy, corresponding to an absolute measurement accuracy of 0.1%. To measure the emittance, MICE uses two solenoidal spectrometers. The Spectrometer Solenoids are designed to have 4 T solenoidal fields, uniform at 3 per mil level in the tracking volumes. Analysis of magnetic field measurements of the Spectrometer Solenoids will be discussed, and results of extracting precise coil positions, angles, and coil radius measurements for input into magnet models will be presented.

TUPFI067

Energy Deposition and Shielding Study of the Front End for the Neutrino Factory

proton, target, solenoid, factory

1505

P. Snopok
IIT, Chicago, Illinois, USA
D.V. Neuffer
Fermilab, Batavia, USA
C.T. Rogers
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom

In the Neutrino Factory and Muon Collider muons are produced by firing high energy protons onto a target to produce pions. The pions decay to muons which are then accelerated. This method of pion production results in significant background from protons and electrons, which may result in heat deposition on superconducting materials and activation of the machine preventing manual handling. In this paper we discuss the design of a secondary particle handling system. The system comprises a solenoidal chicane that filters high momentum particles, followed by a proton absorber that reduces the energy of all particles, resulting in the rejection of low energy protons that pass through the solenoid chicane. We detail the design and optimization of the system, its integration with the rest of the muon front end, and energy deposition and shielding analysis in MARS15.

TUPWA030

Impedances Calculations of Bellows in HLS II Storage Ring

impedance, wakefield, storage-ring, coupling

1784

Q. Zhang, W. Li, L. Wang
USTC/NSRL, Hefei, Anhui, People's Republic of China

The upgrade project of Hefei Lighe Source storage ring is carrying on.In this project,a new Bellows, in which shielding is provided by sprung fingers which can slide along the beam screen,is installed at the accelerator interaction area In order to reduce this impedance to an acceptable value. The contributions of Bellows to short range wakefields and broadband impedance were calculated numerically by Mafia code .

WEPWA015

Progress in Construction of the 35 MeV Compact Energy Recovery Linac at KEK

linac, gun, cryomodule, laser

2159

S. Sakanaka, S. Adachi, M. Akemoto, D.A. Arakawa, S. Asaoka, K. Enami, K. Endo, S. Fukuda, T. Furuya, K. Haga, K. Hara, K. Harada, T. Honda, Y. Honda, H. Honma, T. Honma, K. Hosoyama, K. Hozumi, E. Kako, Y. Kamiya, H. Katagiri, H. Kawata, Y. Kobayashi, Y. Kojima, Y. Kondou, T. Kume, T. Matsumoto, H. Matsumura, H. Matsushita, S. Michizono, T. Miura, T. Miyajima, S. Nagahashi, H. Nakai, H. Nakajima, N. Nakamura, K. Nakanishi, K. Nakao, K.N. Nigorikawa, T. Nogami, S. Noguchi, S. Nozawa, T. Obina, T. Ozaki, F. Qiu, H. Sagehashi, H. Sakai, S. Sasaki, K. Satoh, M. Satoh, T. Shidara, M. Shimada, K. Shinoe, T. Shioya, T. Shishido, M. Tadano, T. Takahashi, R. Takai, T. Takenaka, Y. Tanimoto, M. Tobiyama, K. Tsuchiya, T. Uchiyama, A. Ueda, K. Umemori, K. Watanabe, M. Yamamoto, Y. Yamamoto, Y. Yano, M. Yoshida
KEK, Ibaraki, Japan
E. Cenni
Sokendai, Ibaraki, Japan
R. Hajima, S.M. Matsuba, R. Nagai, N. Nishimori, M. Sawamura, T. Shizuma
JAEA, Ibaraki-ken, Japan
H. Takaki
ISSP/SRL, Chiba, Japan

The 35-MeV Compact Energy Recovery Linac (the Compact ERL or cERL) is under construction at the High Energy Accelerator Research Organization (KEK) in Japan. With the Compact ERL, we aim at establishing cutting-edge technologies for the GeV-class ERL-based synchrotron light source. To install the accelerator components of the cERL, we have constructed a shielding room having an area of about 60 m x 20 m. We have then installed a 500-kV DC photocathode gun, a 5-MV superconducting (SC) cryomodule for the injector, a 30-MV SC cryomodule for the main linac, and some of the other components. High-power test on the main SC cryomodule is underway in December, 2012. High-power or high-voltage tests on the injector cryomodule and on the DC gun are planned during January to March, 2013. An injector of the Compact ERL will be commissioned in April, 2013. We report the newest status of its construction.

WEPWO011

In-vacuum Temperature Measurement of Niobium Components using Infrared Pyrometry during Electron Beam Welding Procedure

cavity, vacuum, electron, controls

2334

L. Monaco, P. Michelato, C. Pagani, D. Sertore
INFN/LASA, Segrate (MI), Italy
V. Battista, G. Corniani, M. Festa
Ettore Zanon S.p.A., Schio, Italy

Electron beam welding (EBW) is widely used in the construction of Niobium Superconducting RF cavities. The welding sequence of such a complex structure, foresees many welding operations. The welding parameters depend on many variables as the material thickness, but also on the component temperature before each weld. This paper presents a technique to measure the temperature of Nb components in vacuum during the EBW operation using an IR pyrometer placed outside the vacuum chamber through an appropriate vacuum viewport. With the current configuration the system can measure temperatures up to 350°C in the vacuum conditions of the EBW vacuum chamber (10-5-10^-6 mbar). The technique was used to optimize the time interval between each subsequent equatorial weld operation during Nb cavities production at Ettore Zanon, increasing the welding procedure reliability and decreasing the waiting time by control of the temperatures in the weld region. Moreover this technique can be generally used for in vacuum measurements of components from room temperature up to about 350 °C. Future developments are under way to make this technique compatible with UHV and increasing the measurement range.

WEPEA041

Actions To Mitigate The Radiation Damage to Electronics at the LHC

radiation, hadron, controls, civil-engineering

2591

A.-L. Perrot, M.B.M. Barberan Marin, J.-P. Corso, K. Foraz, M. Lazzaroni, Y. Muttoni
CERN, Geneva, Switzerland

The level of flux of hadrons with energy in the multi MeV range expected from the collisions at the LHC interaction Points 1, 5 and 8 and from the collimation system at Point 7 will induce Single Event Errors (SEEs) in the standard electronics present in many of the control equipment installed in LHC underground. Furthermore, a risk of SEEs induced by thermal neutrons cannot be excluded. Such events would perturb the LHC operation, possibly leading to a stop of the machine. Main mitigation actions will be implemented during the first LHC Long Shutdown of 2013/2014 (LS1) to reduce the SEE occurrence. This paper summarizes the mitigation measures and their associated foreseen improvements in terms of SEEs. It presents the organization process and associated planning highlighting the impacts with the overall LHC LS1 planning and the main concerns during implementation.

WEPEA057

Numerical Simulations to Evaluate the Performance of CERN PS Dummy Septum to Reduce Irradiation for the Multi-Turn Extraction

septum, extraction, kicker, beam-losses

2636

C. Hernalsteens, S. Damjanovic, S.S. Gilardoni, M. Giovannozzi
CERN, Geneva, Switzerland

The losses created by the proposed Multi-Turn Extraction (MTE) at the CERN PS induces high activation of the magnetic extraction septum due to the de-bunched longitudinal beam structure requested to transfer the beam to the SPS. A mitigation measure is under study aiming at localizing losses in a well-shielded area by shadowing the magnetic extraction septum thanks to septum-like passive device. Such a solution is based on a so-called dummy septum, a blade which absorbs particles during the rise time of the extraction kickers for MTE beams. The efficiency of the scheme is presented in this paper. The quantitative estimate is based on detailed simulations that analyse the beam-matter interaction and provide a determination of the shadowing effect of the dummy septum.

WEPFI067

FETS RF System Design and Circulator Testing

rfq, klystron, ion, insertion

2851

S.M.H. Alsari, J.K. Pozimski, P. Savage
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
M. Dudman, A.P. Letchford
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom

The Front End Test Stand (FETS) is an experiment based at the Rutherford Appleton Laboratory (RAL) in the UK. In this experiment, the first stages necessary to produce a very high quality, chopped H⁻ ion beam as required for the next generation of high power proton accelerators (HPPAs) are designed, built and tested. HPPAs with beam powers in the megawatt range have many possible applications including drivers for spallation neutron sources, neutrino factories, accelerator driven sub-critical systems, waste transmuters and tritium production facilities. RF system outline and design options of the waveguide and coaxial parts and shielding are presented and discussed in this paper. Experimental measurements of the system’s circulator will be presented as part of the system testing results.

THOAB201

Development of the Dielectric Wall Accelerator

proton, dipole, simulation, radiation

3115

A. Zografos, T. Brown, C. Cohen-Jonathan, C. Hettler, F. Huang, V. Joshkin, K. Leung, M. Moyers, Y.K. Parker, D. Pearson, M. Rougieri
CPAC, Livermore, CA, USA
R.W. Hamm
R&M Technical Enterprises, Pleasanton, California, USA

The Compact Particle Accelerator Corporation has developed an architecture to produce pulsed proton bunches that will be suitable for proton beam therapy. The Dielectric Wall Accelerator engineering prototype includes a RFQ injection system with a pulsed kicker to select the desired proton bunches and a linear accelerator incorporating a High Gradient Insulator with stacked transmission to produce the required voltage. The transmission lines are switched with solid state laser driven optical switches. A computational model has been developed that is in very good agreement with the experimental results. The system is presently achieving accelerating gradients of approximately 15 MeV/m. The computational model has been used to design the next generation system that will achieve 25 MeV/m by early 2013. This paper will discuss the status of the apparatus, the basic elements of the computational model, experimental results and comparison to the model predictions. In addition, the paper will present concepts for proton therapy systems that incorporate the Dielectric Wall Accelerator and fully leverage its features to achieve clinical requirements.

Slides THOAB201 [1.650 MB]

THOBB201

Pathway to a Post Processing Increase in Q0 of SRF Cavities

cavity, niobium, SRF, cryogenics

3129

O. Kugeler, J. Knobloch, J.M. Vogt
HZB, Berlin, Germany
S. Aull
CERN, Geneva, Switzerland

A significant improvement of Q0 to values larger than 3.2x10¹⁰ at 1.8K has been repeatedly achieved in an SRF cavity by thermal cycling, i.e. heating the cavity briefly above transition temperature and subsequent cooling. Conceivable explanations for this effect reach from effectivity deviations of the magnetic shielding to thermal currents to hydrogen diffusion. Experimental We have experimentally verified some of these explanations, leaving a direct impact of cooling dynamics on frozen flux as the most plausible one. The pathway to this finding is being presented and the application to SRF systems is elicited.

Slides THOBB201 [1.184 MB]

THPEA027

Radiation Calculations for Advanced Proton Therapy Facility

proton, radiation, simulation, target

3201

J.Q. Xu, J.J. Lu, G. Wang, X. Xia
SINAP, Shanghai, People's Republic of China

The shielding calculations for Advanced Proton Therapy Facility (APTRON), which is under design in Shanghai, were carried out. The thickness of radiation shielding walls for the accelerator and treatment rooms of APTRON were determined by Monte Carlo simulation and empirical formula. Beam loss scenarios and workloads of different energy at LINAC, synchrotron, beam transport line and treatment are given for the calculations. The calculations were carried out for the proton energy of 150MeV, 220MeV and 250MeV, and the targets of iron and equivalent tissue material. Source terms and attenuation length were calculated with different angles by the simulation using FLUKA code. Based on the source terms and the attenuation length, the thickness of the bulk walls were determined. Local shielding and maze design were also concerned.

THPEA039

Radiation Protection Study for the Shielding Design of the LINAC 4 Beam Dump at CERN

linac, radiation, neutron, simulation

3225

J. Blaha, J. Vollaire
CERN, Geneva, Switzerland

Linac4, a new 160 MeV H⁻ accelerator, is currently being constructed at CERN. The accelerator is terminated by a dump collecting beam which is not intended for further utilization. The aim of this study is to determine an optimal shielding of the beam dump fulfilling the radio-protection requirements. The proposed shielding must take into account different accelerator operational phases, the space constraints inside the accelerator vault as well as the decommissioning of the installation at the end of its lifetime. Therefore a detailed Monte-Carlo calculation using FLUKA particle transport and interaction code has been performed and the relevant physics quantities have been evaluated for different irradiation profiles and shielding material. Moreover, the residual dose rate and induced activation have been calculated for several cooling times in order to optimize the choice of the shielding material following the ALARA principle. Finally the airborne radioactivity induced by particles escaping the shielding as well as the activation of the beam dump cooling water have been also calculated using FLUKA and simplified laminar flow models.

THPFI015

In-situ Degassing of the Ferrite Cores in the Extraction Kicker Magnets of the J-PARC 3-GeV RCS

vacuum, kicker, target, quadrupole

3324

J. Kamiya, Y. Hikichi, M. Kinsho, M. Nishikawa, N. Ogiwara, K. Suganuma, T. Yanagibashi
JAEA/J-PARC, Tokai-mura, Japan

Kicker magnets extract the accelerated beam to the beam transport lines in the RCS of the J-PARC. The kicker magnets mainly consist of Ni-Zn ferrite cores and Al alloy plates, and are installed in a vacuum to prevent discharge because a high voltage is applied for a short period. It is important to reduce the outgassing of water vapor from the ferrite cores. Although the kicker magnets have been working well, recently the vacuum quality became a little poor. Thus, we developed the in-situ degassing method for the ferrite cores. This is achieved by directing the heat from the heat source to the kicker magnet and not to the chamber wall. With the test stand we succeeded to flow almost all the heat toward the kicker magnet and to bake out the ferrite cores about 150°C, maintaining the temperature of the chamber wall less than 50°C. As the previous work with TDS measurements revealed that the absorbed water molecules can be easily removed by the bake-out at 100-150°C in a vacuum, the outgassing from the ferrite cores was successfully reduced. The details of the in-situ degassing method will be reported, including the practical method to reduce the outgassing of the working kickers.

THPFI020

Radiation Shielding Design for Medical Cyclotrons

cyclotron, proton, target, radiation

3339

F. Wang, T. Cui, X.L. Jia, Z.G. Li, T.J. Zhang, X.Z. Zhang
CIAE, Beijing, People's Republic of China

With the increasing applications of cyclotrons in health care, a number of cyclotrons ranging from several MeVs to hundreds MeVs have used for radio diagnostic and radiation therapy. A 14 MeV PET cyclotron, CYCIAE-14, has been installed in a shielding building for tests at CIAE that can be used for FDG production and boron neutron capture therapy (BNCT). In the mean time, the development of a 235MeV cyclotron, CYCIAE-235, which can be used for proton therapy, is in progress at the same laboratory. In terms of the cyclotron application in factories and hospitals, an appropriate radiation shielding design is of critical importance. In the case of CYCIAE-14 and CYCIAE-235, the neutron source of different cyclotrons has been estimated to define the thickness of the total shielding, and the concrete is selected as the main shielding material. For CYCIAE-14 specifically, local shielding has been implemented. This paper will give an introduction to the radiation shielding design for CYCIAE-14 and CYCIAE-235 respectively. The typical layout for the application of the two machines is presented in this paper which can be applied in factories and hospitals as well.

THPFI027

STUDY ON STRUCTURE AND THERMAL ANALYSIS OF CSNS R BEAM DUMP

controls, neutron, proton, target

3356

L. Liu, L. Kang, X.J. Nie, H. Qu
IHEP, Beijing, People's Republic of China

The China Spallation Neutron Source (CSNS) accelerator systems will provide a 1.6 Gev proton beam to a target for neutron production. Beam dump system is an important part of CSNS, and it is used to incept the waste beam. The beam dump system is composed with vacuum part and shielding part. For the design of shielding part, the material is steel at the centre and concrete outside, we must control the temperature of steel and concrete not too high, and it will be a serious problem that the concrete crazes because of the high temperature. So the thermal analyses must be done to ensure safety. Taking CSNS R dump for example, we use software to make model and analyze the thermal, then optimizing the result. According to the result, we control the work time and dimension of the beam to control the temperature of the iron and concrete. This article expatiate the study on the structure design and thermal analyses.

THPFI031

Development of Beam Collimators for the 1.6 GeV Rapid Cycling Synchrotron of CSNS

collimation, vacuum, synchrotron, simulation

3364

J.B. Yu, pf.He. He, L. Kang, H. Qu, Y.Q. Zou
IHEP, Beijing, People's Republic of China

In order to reduce the uncontrolled losses in the localized station, the beam collimation system has been performed for the 1.6GeV synchrotron of CSNS. The CSNS/RCS transverse collimation system is designed to be a two-stage system which consists of one primary collimator and four secondary collimators. Much work about machinery design and manufacture of the collimation system has been done till now. This paper will show the exterior frame of collimation system by considering the physical demands and spatial position. Then the progress which contains design and machining of collimators will also be introduced. Finally some problems which are mainly about the design of secondary collimators will be mentioned.

THPFI062

Design of Air-cooled Beam Dump for Extraction Line of PS Booster

simulation, booster, cavity, proton

3436

A. Perillo-Marcone, T. Antonakakis, M. Battistin, M.A. Czapski, G.W. Mason, E.M. Nowak, A. Sarrió Martínez, S. Sgobba, V. Venturi, V. Vlachoudis
CERN, Geneva, Switzerland

A new beam dump has been designed, which withstands the future proton beam extracted from the PS Booster at CERN, consisting of up to 10¹⁴ protons per pulse at 2 GeV after its upgrade in 2018/2019. In order to be able to efficiently release the deposited heat, the new dump will be made out of a single cylindrical block of a copper alloy and be cooled by forced ventilation. In order to determine the energy density distribution deposited by the beam in the dump, Monte Carlo simulations were performed using FLUKA, and thermo-mechanical analyses carried out by importing the energy density into Ansys. In addition, CFD simulations of the airflow were carried out in order to accurately estimate the heat transfer convection coefficient on the surface of the dump. In this paper we describe the design process and highlight the constraints of integrating a new dump for increased beam power into the existing facility.

THPFI067

The Mechanical Design, Fabrication, and Performance of the DCCT for TPS

vacuum, storage-ring, electron, high-voltage

3451

C.-C. Chang, C.K. Chan, J.-R. Chen, G.-Y. Hsiung, H.P. Hsueh
NSRRC, Hsinchu, Taiwan
J.-R. Chen
National Tsing Hua University, Hsinchu, Taiwan

This paper describes the DC current transformers (DCCT), designed and fabricated for Taiwan Photon Source (TPS); including the mechanical structure, dissimilar material welding process for the DCCT chamber, electronically and vacuum performance testing. In the structure, a ceramic break disc is provided and jointed between to ends of the beam duct. The electrical connection path is interrupted in the beam duct adjacent to the transformer. To avoid the sensor measured the wall current and other unnecessary circulating currents. The DCCT toroid is independent installed outside of a vacuum beam duct to measure the average beam current. In order to reduce the influence of external magnetic field for the sensor, two layers of Mu metal shell are installed. The performance and progress for the DCCT are described in this paper.

THPFI092

Design of the Mercury Handling System for a Muon Collider/Neutrino Factory Target

target, collider, factory, proton

3505

K.T. McDonald
PU, Princeton, New Jersey, USA
J.S. Berg, H.G. Kirk, H. K. Sayed
BNL, Upton, Long Island, New York, USA
X.P. Ding
UCLA, Los Angeles, California, USA
V.B. Graves
ORNL, Oak Ridge, Tennessee, USA
N. Souchlas, R.J. Weggel
Particle Beam Lasers, Inc., Northridge, California, USA

The baseline target concept for a Muon Collider or Neutrino Factory is a free mercury jet within a 20-T magnetic field being impacted by an 8-GeV proton beam. A pool of mercury serves as a receiving reservoir for the mercury and a dump for the unexpended proton beam. Modifications to this baseline are discussed in which the field at the target is reduced from 20 to 15 T, and in which the magnetic field drops from its peak value down to 1.5 T over 7 rather than 15 m.

THPME010

Magnetic Shielding for the 1.3 GHz Cryomodule at IHEP

simulation, cavity, SRF, cryomodule

3528

S. Jin, Y. Chen, J. Gao, R. Ge, Y. Liu, Z.C. Liu, J.Y. Zhai, T.X. Zhao, H.J. Zheng
IHEP, Beijing, People's Republic of China
F. Yang
China Iron and Steel Research Institute Group, Beijing, People's Republic of China

An ILC-type Superconducting RF (SRF) accelerating unit is being studied at IHEP. In order to achieve the design performance including both accelerating gradient and quality factor, the SRF cavity must be cooled with ambient magnetic field well shielded to the level of several mG[1,2]. In this paper, permeability of several kinds of materials for magnetic shielding made in China is systematically studied in cooperation with China Iron & Steel Research Institute Group (CISRI) and reported for the first time. By using proper material, numerical calculation for the magnetic shielding design was done via the program of Opera-3D, and then magnetic shield was fabricated by CISRI. This paper will show those studies above and the final magnetic shielding effect at room temperature. Comparisons between simulation result and real effect will also be discussed in the paper, as well as the preliminary analysis for the magnetic field leaking of this design.

THPWO020

Simulations on the Boundary Fields of 4-rod RFQ Electrodes

rfq, simulation, cavity, quadrupole

3803

J.S. Schmidt, B. Koubek, A. Schempp
IAP, Frankfurt am Main, Germany

If the RF design of a 4-rod Radio Frequency Quadrupole (RFQ) is not performed carefully with respect to the boundary fields of its electrodes, it can produce errors compared to beam dynamic simulations. An additional field component can be induced on the beam axis, which influences the properties of the particle beam, like energy per nucleon for example, dramatically. Therefore, the influences of different geometric parameters of 4-rod RFQs on these fields have been studied in detail. The results of these simulations will be presented in this paper.

THPWO085

Numerical and Experimental Study for the Characterization of the Spallation Target Performance of the Ultracold Neutron Source at the Paul Scherrer Institut

neutron, target, simulation, proton

3960

V. Talanov, M. Wohlmuther
PSI, Villigen PSI, Switzerland

Results of numerical calculation and experimental characterization of the neutron flux profile in the vicinity of the ultracold neutron source (UCN) at the Paul Scherrer Institut (PSI) are presented. At first, the MCNPX-based model of the Monte-Carlo simulation with its detailed description of the so-called ‘Cannelloni’-type spallation target assembly and the realistic proton beam profile modeling is described. Thereafter the experimental determination of the thermal neutron flux profile using the gold foil activation, along the height of the UCN vacuum tank, starting from the proton beam plane, is presented. Both calculations and measurements were performed for the standard operation mode, with several seconds of the full proton beam on the target. Finally, a comparison of simulation and experimental results is discussed.