2011 Particle Accelerator Conference - List of Keywords (neutron)

Paper	Title	Other Keywords	Page
MOODN6	Muon Collider Interaction Region and Machine-detector Interface Design	quadrupole, dipole, collider, background	82
	N.V. Mokhov, Y. Alexahin, V. Kashikhin, S.I. Striganov, A.V. Zlobin Fermilab, Batavia, USA
	Funding: Work is supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy One of the key systems of a Muon Collider (MC)- seen as the most exciting options for the energy frontier machine in the post-LHC era - is its interaction region (IR). Designs of its optics, magnets and machine-detector interface are strongly interlaced and iterative. As a result of recent comprehensive studies, consistent solutions for the 1.5 TeV c.o.m. MC IR have been found and are described here. To provide the required momentum acceptance, dynamic aperture and chromaticity, innovative approach was used for the IR optics. Conceptual designs of large-aperture high-field dipole and high-gradient quadrupole magnets based on Nb₃Sn superconductor were developed and analyzed in terms of the operation margin, field quality, mechanics, coil cooling and quench protection. Shadow masks in the interconnect regions and liners inside the magnets are used to mitigate unprecedented dynamic heat deposition due to muon decays (~1 kW/m). It is shown that an appropriately designed machine-detector interface with sophisticated shielding in the detector has a potential to substantially suppress the background rates in the MC detector.
	Slides MOODN6 [1.233 MB]

MOP007	The Development Status of Compact Linear Accelerator in Korea	plasma, ECRIS, ECR, ion	112
	B.S. Lee, M. Won Korea Basic Science Institute, Busan, Republic of Korea J.-K. Ahn Pusan National University, Pusan, Republic of Korea T. Nakagawa RIKEN Nishina Center, Wako, Japan
	Funding: This work was supported by KBSI D30300 to M.S Won The establishment of a compact linear accelerator is in progress by Korea Basic Science Institute. The main capability of this facility is the production of multiply ionized metal clusters and the generation of intense beams of highly charged ions for material, medical and nuclear physical research. To generate the intense beam of highly charged ions, we will develop an Electron Cyclotron Resonance Ion Source (ECRIS) using 28GHz microwaves. For this ECRIS, the designing of a superconducting magnet, microwave inlet, beam extraction, and plasma chamber were in progress. A superconducting magnet system have also being developed. In this presentation, I report the current status of our compact linear accelerator development and future plan.

MOP234	Beam Position and Phase Monitors for the LANSCE Linac	linac, controls, monitoring, instrumentation	548
	R.C. McCrady, J.D. Gilpatrick, J.F. Power LANL, Los Alamos, New Mexico, USA
	Funding: This work is supported by the US Department of Energy under contract DE-AC52-06NA25396 New beam-position and phase monitors are under development for the linac at the Los Alamos Neutron Science Center. Transducers have been designed and are being fabricated. We are considering many options for the electronic instrumentation to process the signals and provide position and phase data with the necessary precision and flexibility to serve the various required functions. We’ll present the requirements of the system and the various options under consideration for instrumentation along with the advantages and shortcomings of these options.

MOP256	Upgrading the Data Acquisition and Control System of the LANSCE LINAC	controls, linac, EPICS, proton	588
	D. Baros LANL, Los Alamos, New Mexico, USA
	Funding: This work has benefited from the use of the LANSCE at LANL. This facility is funded by the US DOE and operated by LANS for NSSA under Contract DE-AC52-06NA25396. Los Alamos National Laboratory LANL is in the process of upgrading the control system for the Los Alamos Neutron Science Center (LANSCE) linear accelerator. The 38 year-old data acquisition and control equipment is being replaced with COTS hardware. An overview of the current system requirements and how the National Instruments cRIO system meets these requirements will be given, as well as an update on the installation and operation of a prototype system in the LANSCE LINAC. LANL Release Number: LA-UR 10-06605

MOP272	Radiation Dose Level in the SSRF during Normal Operation	radiation, monitoring, storage-ring, injection	615
	X.J. Xu, P. Fei, R. Qin, W. Shen, X. Xia, D. Zhang, J.Z. Zhou SINAP, Shanghai, People's Republic of China
	Shanghai Synchrotron Radiation Facility (SSRF) has been commissioned since December 2007, and has been formally operated since May 2009. In order to ensure the radiation safety for staff members and publics, the radiation levels of the workplace, the environment and the staff are monitored through a real-time network of gamma and neutron monitors as well as through TLD passive dosimeters. This paper reports the results of the radiation monitoring. From these results, we found that the annual dose equivalents were good to meet the management values of SSRF.

MOP288	Progress Report on Development of the RING Cavity for Laser-based Charge Stripping of Hydrogen Ions	laser, radiation, ion, recirculation	657
	R. Tikhoplav RadiaBeam, Santa Monica, USA I. Jovanovic Penn State University, University Park, Pennsylvania, USA
	Charge stripping of hydrogen ions is the first stage of any high intensity proton accelerator. To achieve higher-charge proton sources, the stripping efficiency must be improved, especially in the context of the Spallation Neutron Source at Oak Ridge National Laboratory. A method based on laser-ion interaction has a great potential for increasing efficiency. The approach of this proposed project is to design a laser cavity based on the Recirculation Injection by Nonlinear Gating (RING) technique. This paper reports on the progress of the development of the RING cavity.

TUP003	Beam Stop of Spiral2 Facility: Activation and Residual Dose Rate Calculations	simulation, photon, factory, shielding	811
	A. Mayoral, M. García, D. López, F. Ogando, J. Sanz, P. Sauvan UNED, Madrid, Spain
	Funding: SPIRAL 2 Preparatory Phase. European Strategy Forum on Research Infrastructures. Seventh Framework Programme Ref 212692 The Spanish Ministery of Science and Innovation. Project ENE2009-07572 SPIRAL2 facility is expected to produce 5mA of deuterons at 40 MeV. A beam dump device (BD) has been designed to stop the beam. In this paper we assess the residual dose rates (RDR) in the BD room during beam-off phases. MCNPX was used to deal with deuterons transport and production and transport of secondary neutrons. Deuteron and neutron induced activation were computed using ACAB and EAF2007. Decay gammas were transported using MCNPX to compute RDR. Dose rates at cooling times up to one year are presented, showing that it is mainly due to BD copper induced activation. The uncertainties in the results can be attributed to: i) the reliability of the d-Cu activation cross sections reactions, ii) the computational approach used to assess the neutron source. The troublesome radioisotopes from d-Cu and their formation reactions were identified. EAF2007 cross sections for these reactions were compared with the available experimental data. Regarding the computational approach to determine the neutron source from d-Cu interactions two options were used: i) built-in nuclear models of MCNPX, ii) TENDL and MCUNED. The available experimental data were used for benchmarking. J. Sanz et al. ACAB. User’s manual NEA-1839 (2009) A.J. Koning et al. TENDL2008 http://www.talys.eu/tendl-2008/ * P.Sauvan et al. Nucl. Instr.and Meth. A 614 (2010)3 323-330.

TUP004	GEANT4 Modelling of Heat Deposition into the ISIS Muon Target	target, proton, ion, simulation	814
	A. Bungau, R. Cywinski University of Huddersfield, Huddersfield, United Kingdom R.J. Barlow Cockcroft Institute, Warrington, Cheshire, United Kingdom C. Bungau Manchester University, Manchester, United Kingdom P.J.C. King, J.S. Lord STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
	The energy deposition on the ISIS muon target and the temperature profiles are analysed in this paper. The thermal modelling is performed using the GEANT4 Monte Carlo code. Heat deposition patterns are also simulated for alternative target geometries. Energy deposition in the collimators is also discussed.

TUP146	Large Aperture Quadrupole Magnets for ISIS TS-1 and TS-2	quadrupole, dipole, target, proton	1103
	S.M. Gurov, A.M. Batrakov, M.F. Blinov, F.A. Emanov, V.V. Kobets, V.A. Polukhin, A.S. Tsyganov, P. Vobly, T.A. Yaskina BINP SB RAS, Novosibirsk, Russia S.J.S. Jago, J. Shih, S.F.S. Tomlinson STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	The ISIS pulsed neutron and muon source at the Rutherford Appleton Laboratory has two target stations TS-1 and TS-2. Budker Institute of Nuclear Physics developed, produced and delivered seven type Q13 quadrupole magnets with an aperture diameter of 310 mm for TS-2 beam transfer line. Later an additional three quadrupoles with integrated dipole coils were developed and delivered to ISIS TS1. To improve the field quality across the full current range a special pole profile and end chamfer were designed using the MERMAID code. The magnetic field map was measured by a set of Hall probes. Moreover, BINP produced a rotating coil with radius 120 mm for field quality measurements.

TUP179	Energy Deposition within Superconducting Coils of a 4 MW Target Station	target, shielding, simulation, factory	1166
	X.P. Ding UCLA, Los Angeles, California, USA J.J. Back University of Warwick, Coventry, United Kingdom R.C. Fernow, H.G. Kirk, N. Souchlas BNL, Upton, Long Island, New York, USA K.T. McDonald PU, Princeton, New Jersey, USA R.J. Weggel Particle Beam Lasers, Inc., Northridge, California, USA
	Funding: Work Supported by the United States Department of Energy, Contract No. DE-AC02-98CH10886. A study of energy deposition within superconducting coils of a 4 MW target station for a neutrino factory or muon collider is presented. Using the MARS code, we simulate the energy deposition within the environment surrounding the target. The radiation is produced by interactions of intense proton beams with a free liquid mercury jet. We study the influence of different shielding materials and shielding configurations on the energy deposition in the superconducting coils of the target/capture system. We also examine energy depositions for alternative configurations that allow more space for shielding, thus providing more protection for the superconducting coils.

TUP275	SNS Linac Modulator Operational History and Performance	linac, high-voltage, klystron, monitoring	1340
	V.V. Peplov, D.E. Anderson, R.I. Cutler, M. Wezensky ORNL, Oak Ridge, Tennessee, USA J.D. Hicks, R.B. Saethre ORNL RAD, Oak Ridge, Tennessee, USA
	Fourteen High Voltage Converter Modulators (HVCM) were initially installed at the Spallation Neutron Source Linear Accelerator (SNS Linac) at the Oak Ridge National Laboratory in 2005. A fifteenth HVCM was added in 2009. Each modulator provides a pulse of up to 140 kV at a maximum width of 1.35 msec. Peak power level is 11 MW with an 8% duty factor. The HVCM system must be available for neutron production (NP) 24/7 with the exception being two, 6-week maintenance periods per year. HVCM reliability is one of the most important factors to maximize Linac availability and achieve SNS performance goals. During the last few years several modifications have been implemented to improve the overall system reliability. This paper presents operational history of the HVCM systems and examines failure mode statistical data since the modulators began operating at 60 Hz. System enhancements and upgrades aimed at providing long term reliable operation with minimal down time are also discussed in the paper.

WEODS2	High-Power Targets: Experience and R&D for 2 MW	target, radiation, proton, simulation	1496
	P. Hurh Fermilab, Batavia, USA O. Caretta, T.R. Davenne, C.J. Densham, P. Loveridge STFC/RAL, Chilton, Didcot, Oxon, United Kingdom N. Simos BNL, Upton, Long Island, New York, USA
	High-power particle production targets are crucial elements of future neutrino and other rare particle beams. Fermilab plans to produce a beam of neutrinos (LBNE) with a 2.3 MW proton beam (Project X). Any solid target is unlikely to survive for an extended period in such an environment - many materials would not survive a single beam pulse. We are using our experience with previous neutrino and antiproton production targets, along with a new series of R&D tests, to design a target that has adequate survivability for this beamline. The issues considered are thermal shock (stress waves), heat removal, radiation damage, radiation accelerated corrosion effects, physics/geometry optimization and residual radiation.

WEP010	Design of the Bilbao Accelerator Low Energy Extraction Lines	quadrupole, linac, dipole, DTL	1519
	Z. Izaola, I. Rodríguez ESS-Bilbao, Zamudio, Spain E. Abad, I. Bustinduy, R. Martinez, F. Sordo Balbin, D. de Cos ESS Bilbao, Bilbao, Spain D.J. Adams, S.J.S. Jago STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom F.J. Bermejo Bilbao, Faculty of Science and Technology, Bilbao, Spain V. Etxebarria, J. Portilla University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain
	Funding: European Spallation Source - Bilbao The ESS-Bilbao linac will accelerate H+ and H− beams up to 50 MeV, which need to be transported to three laboratories, where different types of experiments will be conducted. This paper reports on the preliminary design of the transfer line, which is mainly performed based on beam dynamics simulations.

WEP224	Operational Status and Life Extension Plans for the Los Alamos Neutron Science Center (LANSCE)	proton, linac, target, scattering	1906
	J.L. Erickson, D. Rees LANL, Los Alamos, New Mexico, USA
	Funding: Work supported by the U. S. Department of Energy, National Nuclear Security Administration, Contract No. DE-AC52-06NA25396 – Publication Release LA-UR- 10-06556 The Los Alamos Neutron Science Center (LANSCE) accelerator and beam delivery complex generates the proton beams that serve three neutron production sources, a proton radiography facility and a medical and research isotope production facility. The recent operating history of the facility, including both achievements and challenges, will be reviewed. Plans for performance improvement will be discussed, together with the underlying drivers for the ongoing LANSCE Linac Risk Mitigation project. The details of this latter project will be discussed. The status of accelerator-related plans for the MaRIE Project (Matter-Radiation Interactions in Extremes Experimental Project) will also be discussed. Taken together, the LANSCE Linac Risk Mitigation Project and the MaRIE initiative demonstrate a commitment to investment in the ongoing operation and improvement of the facility, and a resurgent interest in the spectrum of science accessible at LANSCE. These plans will assure continued facility operational and scientific vitality well beyond 2020.

WEP271	Development of a Permanent-Magnet Microwave Ion Source for a Sealed-Tube Neutron Generator	ion, ion-source, plasma, ECR	1984
	O. Waldmann, B.A. Ludewigt LBNL, Berkeley, California, USA
	Funding: Supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. A microwave ion source has been designed and constructed for use with a sealed-tube, high-yield neutron generator. When operated with a tritium-deuterium gas mixture the generator will be capable of producing 5 · 10¹¹ n/s in non-proliferation applications. Microwave ion sources are well suited for such a device because they can produce high extracted beam currents with a high atomic fraction at low gas pressures of 0.2 − 0.3 Pa required for sealed tube operation. The magnetic field strength for achieving electron cyclotron resonance (ECR) condition, 87.5 mT at 2.45 GHz microwave frequency, was generated and shaped with permanent magnets surrounding the plasma chamber and a ferromagnetic plasma electrode. This approach resulted in a compact ion source that matches the neutron generator requirements. The needed proton-equivalent extracted beam current density of 40 mA/cm² was obtained at moderate microwave power levels of ∼ 400W. Results on magnetic field design, pressure dependency and atomic fraction measured for different wall materials are presented.

THOAS3	Status of the Oak Ridge Spallation Neutron Source (SNS) RF Systems	klystron, controls, linac, rfq	2050
	T.W. Hardek, M.T. Crofford, Y.W. Kang, M.F. Piller, A.V. Vassioutchenko ORNL, Oak Ridge, Tennessee, USA S.W. Lee, M.E. Middendorf ORNL RAD, Oak Ridge, Tennessee, USA
	The SNS has been delivering production neutrons for five years with first beam delivered to the neutron target at the end of April 2006. On September 18, 2009 SNS officially reached 1 megawatt of beam on target marking the achievement of a decades-old dream of providing a U.S. megawatt class pulsed spallation source. The SNS is now routinely delivering 1 megawatt of beam power to the neutron target at over 85 percent of the scheduled beam time. The present effort is aimed at increasing availability eventually to 95 percent and gradually increasing the intensity to the 1.4 megawatt design level. While the RF systems have performed well since initial installation some improvements have been implemented. This paper provides a review of the SNS RF Systems, an overview of the performance of the various components and a detailed review of RF related issues addressed over the past several years.
	Slides THOAS3 [2.759 MB]

THOCN4	High-Power Options for LANSCE	DTL, linac, proton, klystron	2107
	R.W. Garnett, E.J. Pitcher, D. Rees, L. Rybarcyk, T. Tajima LANL, Los Alamos, New Mexico, USA
	Funding: This work is supported by the U. S. Department of Energy Contract DE-AC52-06NA25396. The LANSCE linear accelerator at Los Alamos National Laboratory has a long history of successful beam operations at 800 kW. We have recently studied options for restoration of high-power operations including schemes for increasing the performance to multi-MW levels. In this paper we will discuss the results of this study including the present limitations of the existing accelerating structures at LANSCE, and the high-voltage and RF systems that drive them. Several plausible options will be discussed and a preferred option will be presented that will enable the first in a new generation of scientific facilities for the materials community. The emphasis of this new facility is "Matter-Radiation Interactions in Extremes" (MaRIE) which will be used to discover and design the advanced materials needed to meet 21st century national security and energy security challenges.
	Slides THOCN4 [2.903 MB]

THP009	Collimator Design of 15 MeV Linear Accelerator Based Thermal Neutron Source for Radiography	target, electron, simulation, linac	2154
	B.J. Patil, V.N. Bhoraskar, S.D. Dhole University of Pune, Pune, India S.T. Chavan, R. Krishnan, S.N. Pethe SAMEER, Mumbai, India A.J. Patil DANA, Pune, India
	Neutron Radiography is a powerful non-destructive testing technique used for the analysis of objects which are widely used in security, medical, nuclear and industrial applications. Optimization of the thermal neutron radiography facility has been carried out using 15 MeV LINAC based neutron source. In this case, a neutron collimator has been designed along with g-n target, moderator, reflector and shielding. The g-n target has been optimized based on their photonuclear threshold. The moderating properties have been studied for few light elements to optimize best suitable moderator for radiography system. The major part of the design was to optimize the collimator for neutron beam which decides quality of the image given. To get best values of collimator parameters such as collimation ratio, gamma content, neuron flux, cadmium ratio, beam uniformity, etc. a FLUKA simulation was carried out. The collimator has been optimized with cadmium lining square cone to capture the scattered thermal neutrons and the collimation ratio to L/D=18. The neutron flux of the optimized facility obtained at the object plane is 1.0·10⁺⁵ n/(cm²-sec¹) and neutron to gamma ratio is 1.0·10⁺⁵ n/(cm²-mR¹).

THP029	Temperature and Optimize Design of Beam Window in the Accelerator	proton, target, vacuum, radiation	2175
	J.J. Tian, H. Hao, G. Liu, H.L. Luo, X.Q. Wang, H.L. Wu USTC/NSRL, Hefei, Anhui, People's Republic of China
	Careful evaluation of the heat-transfer and corresponding problems is important in the beam window in the design and operation of Accelerator Driven sub-critical System (ADS). Using the Monte-Carlo code Fluka, we studied the energy deposition of the beam window in high power proton accelerator. The temperature distribution of the beam window is calculated in presence of the coolant. The process of computation for various materials will be introduced, and an optimized design scheme is given. The results suggest that some measures could be used to reduce the damage to the beam window, such as dividing current into branch currents, expanding the bunch or using beryllium as the material of the beam window, et al.

THP030	GEANT4 Studies of the Thorium Fuel Cycle	proton, simulation, target, scattering	2178
	C. Bungau Manchester University, Manchester, United Kingdom R.J. Barlow UMAN, Manchester, United Kingdom A. Bungau, R. Cywinski University of Huddersfield, Huddersfield, United Kingdom
	Thorium “fuel” has been proposed as an alternative to uranium fuel in nuclear reactors. New GEANT4 developments allow the Monte Carlo code to be used for the first time in order to simulate the time evolution of the concentration of isotopes present in the Thorium fuel cycle. A full study is performed in order to optimise the production of Uranium-233 starting with "pure" Thorium fuels, leading to levels of Uranium-233 which ensure the operation of the nuclear reactor in a regime close to criticality.

THP034	Accelerators for Subcritical Molten Salt Reactors	target, linac, proton, SRF	2181
	R.P. Johnson Muons, Inc, Batavia, USA C. Bowman ADNA, Los Alamos, New Mexico, USA
	Funding: Supported in part by Accelerator Technologies Inc. Accelerator parameters for subcritical reactors that have been considered in recent studies * are based on using solid nuclear fuel much like that used in all operating critical reactors as well as the thorium-burning accelerator-driven energy amplifier proposed by Rubbia et al. An attractive alternative reactor design that used molten salts was experimentally studied at ORNL in the 1960s, where a critical molten salt reactor was successfully operated using enriched U235 or U233 tetrafluoride fuels . These experiments give confidence that an accelerator-driven subcritical molten salt reactor will work as well or better than conventional reactors, having better efficiency due to their higher operating temperature and having the inherent safety of subcritical operation. Moreover, the requirements to drive a molten salt reactor are considerably relaxed compared to a solid fuel reactor, especially regarding accelerator reliability and spallation neutron targetry, to the point that the required technology exists today. http://www.er.doe.gov/hep/files/pdfs/ADSWhitePaperFinal.pdf http://wikipedia.org/wiki/Energy_amplifier * Paul N. Haubenreich and J. R. Engel, Nuc. Apps & Tech, 8, Feb. 1970

THP037	Design of an e-γ Converter for a 10 MeV Electron Beam	target, electron, photon, linac	2184
	L. Auditore, D. Loria, E. Morgana INFN - Gruppo Messina, S. Agata, Messina, Italy L. Auditore, R.C. Barnà, A. Trifirò, M. Trimarchi Università di Messina, Messina, Italy G. Di Bella Università di Messina, Facoltà di Ingegneria, Messina, Italy
	In the last years, the INFN-Gruppo Collegato di Messina has designed and setup an x-ray source based on the 5 MeV electron linac hosted at the Dipartimento di Fisica - Università di Messina. In the meanwhile, and in the framework of an European funding, the group has setup the Centro Ricerche at Villafranca Tirrena (Messina, Italy) which holds a 10 MeV electron linac and which is, at the moment, mainly devoted to industrial Radiation Processing applications. Nevertheless, to the aim to provide also x-ray beams, an e-g converter has been designed by means of the MCNP4C2 simulation code and optimized for a 10 MeV electron beam. A wide investigation has been performed to choose material and thickness for the e-g converter in order to provide the highest x-ray yield. Then, angular distribution and energy spectrum have been simulated to characterize the produced bremsstrahlung beam. Also the target activation has been investigated. Finally, thermal analysis has been performed using a finite element model code, Deform 2D, to choose the definitive mechanical settings of the e-g converter.

THP048	Radiation and Thermal Analysis of Production Solenoid for Mu2e Experimental Setup	solenoid, target, proton, radiation	2208
	V.S. Pronskikh, V. Kashikhin, N.V. Mokhov Fermilab, Batavia, USA
	The Muon-to-Electron (Mu2e) experiment at Fermilab, will seek the evidence of direct muon to electron conversion that cannot be explained by the Standard Model. An 8 GeV 25 kW proton beam will be directed onto a gold target inside a large-bore superconducting Production Solenoid (PS) with the peak field on the axis of ~5T. The negative muons resulting from the pion decay will be captured in the PS aperture and directed by an S-shaped Transport Solenoid towards the stopping target inside the Detector Solenoid. In order for the superconducting magnets to operate reliably and with a sufficient safety margin, the peak neutron flux entering the coils must be reduced by 3 orders of magnitude that is achieved by means of a sophisticated absorber placed in the magnet aperture. The proposed absorber, consisting of W and Cu parts, is optimized for the performance and cost. Results of MARS15 of energy deposition and radiation analysis are reported. The results of the PS magnet thermal analysis, coordinated with the coil cooling scheme, are reported as well for the selected absorber design.

THP053	The New Approximation of Dose Attenuation Curve in Concrete	shielding, ion, heavy-ion, target	2217
	M. Petrichenkov, V.Ya. Chudaev BINP SB RAS, Novosibirsk, Russia
	The analytical approach in shielding calculations is simple and fast method for quick estimations. But it provides less accuracy than Monte-Carlo one. Often the exponential attenuation of dose in shielding is considered. But also it is necessary to take into account the dose increase in the first layers of shielding due to initial accumulation of neutrons. The new approximation of dose attenuation curve in concrete is offered for quick analytical estimations of shielding of hadron accelerators. It allows to make fast estimation of shielding thickness enough correctly.

THP087	G4Beamline and MARS Comparison for Muon Collider Backgrounds	collider, background, electron, simulation	2297
	M.A.C. Cummings, S.A. Kahn Muons, Inc, Batavia, USA D. Hedin, A.O. Morris Northern Illinois University, DeKalb, Illinois, USA J.F. Kozminski Lewis University, Romeoville, Illinois, USA
	Funding: Supported in part by SBIR Grant DE-SC0005447 Technological innovations in recent years have revived interest in muon colliders as the next generation energy frontier machine. The biggest challenge for muon colliders is that muons decay. Advances in muon cooling technology will make the focussing and acceleration of muons to TeV energies possible. The challenge for the detectors in such machines is overcoming the large backgrounds from muon decays in the colliding ring lattice that will inundate the interaction region (IR) and will make triggering and data reconstruction a challenge. Developing simulation tools that can reliably model the environment of the muon collider IR will be critical to physics analyses. We will need to expand the capabilities of current programs and use them to benchmark and verify results against each other. Here we are comparing an emerging capabiligy of G4beamline, an interface for physicists to GEANT4 code, with MARS, a mature program for particle fluences, in developing code for muon collider background studies

THP088	Beam Induced Detector Backgrounds at a Muon Collider	collider, background, shielding, electron	2300
	S.A. Kahn, M.A.C. Cummings, T.J. Roberts Muons, Inc, Batavia, USA D. Hedin, A.O. Morris Northern Illinois University, DeKalb, Illinois, USA J.F. Kozminski Lewis University, Romeoville, Illinois, USA
	Funding: Supported in part by SBIR Grant DE-SC0005447 Muon colliders are considered to be an important future energy frontier accelerator. It is possible to build a large muon collider as a circular machine, even at multi-TeV energies, due to the greatly reduced synchrotron radiation expected from muons. In addition to the same physics processes present in an electron collider, a muon collider will have the potential to produce s-channel resonances such as the various Higgs states at an enhanced rate. For a muon collider with 750 GeV/c mu+ and mu- with 10¹² mu per bunch we would expect 4.3x10⁵ muon decays per meter. These muon decays will produce very energetic off momentum electrons that can produce detector backgrounds that can affect the physics. These backgrounds include electrons from muon decays, synchrotron radiation from the decay electrons, hadrons produced by photo-nuclear interactions, coherent and incoherent beam-beam pair production and Bethe-Heitler muon production. In this paper we will discuss these processes and calculate particle fluxes into the detector volume from these background processes.

THP090	Physics Validation of Monte Carlo Simulations for Detector Backgrounds at a Muon Collider	simulation, electron, background, collider	2303
	A.O. Morris, D. Hedin Northern Illinois University, DeKalb, Illinois, USA M.A.C. Cummings, S.A. Kahn, T.J. Roberts Muons, Inc, Batavia, USA J.F. Kozminski Lewis University, Romeoville, Illinois, USA
	Muon colliders are considered to be an important future energy-frontier accelerator. A muon collider could be built as a circular accelerator into the TeV energy range as a result of the reduced synchrotron radiation expected from the larger rest mass of muons. For a muon collider with 750 GeV μ+ and μ- with 10¹2 μ per bunch, it can be expected that there would be 4.3×10⁵ muon decays per meter per beam. These decays will produce very energetic off-momentum electrons that can produce detector backgrounds that can affect the physics. The main backgrounds include electrons from muon decays, synchrotron radiation from the decay electrons, hadrons produced by photonuclear interactions, coherent and incoherent beam-beam pair-production, and Bethe-Heitler muon production. In this paper we will discuss the simulation results in terms of observed physics processes in G4Beamline.

FROAN1	The European Spallation Source	linac, target, proton, cryomodule	2549
	S. Peggs, H. Danared, M. Eshraqi, H. Hahn, A. Jansson, M. Lindroos, A. Ponton, K. Rathsman, G. Trahern ESS, Lund, Sweden S. Bousson IPN, Orsay, France R. Calaga BNL, Upton, Long Island, New York, USA G. Devanz, R.D. Duperrier CEA/DSM/IRFU, France J. Eguia Fundación TEKNIKER, Eibar (Gipuzkoa), Spain S. Gammino INFN/LNS, Catania, Italy S.P. Møller ISA, Aarhus, Denmark C. Oyon SPRI, Bilbao, Spain R.J.M.Y. Ruber Uppsala University, Uppsala, Sweden T. Satogata JLAB, Newport News, Virginia, USA
	The European Spallation Source (ESS) is a 5 MW, 2.5 GeV long pulse proton linac, to be built and commissioned in Lund, Sweden. The Accelerator Design Update (ADU) project phase is under way, to be completed at the end of 2012 by the delivery of a Technical Design Report. Improvements to the 2003 ESS design will be summarised, and the latest design activities will be presented.
	Slides FROAN1 [1.650 MB]

FROCB2	Science with Light and Neutron Sources	scattering, synchrotron, electron, photon	2596
	S.K. Sinha UCSD, La Jolla, California, USA
	In recent years there has been great progress in the development of accelerator-based light and neutron sources. The speaker will give an overview of the exciting new opportunities provided by the enhanced source capabilities available at present and future facilities. Speaker Sunhil Sinha, a professor in the Physics Department of the University of California at San Diego
	Slides FROCB2 [26.588 MB]

Paper

Title

Other Keywords

Page

MOODN6

Muon Collider Interaction Region and Machine-detector Interface Design

quadrupole, dipole, collider, background

82

N.V. Mokhov, Y. Alexahin, V. Kashikhin, S.I. Striganov, A.V. Zlobin
Fermilab, Batavia, USA

Funding: Work is supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy
One of the key systems of a Muon Collider (MC)- seen as the most exciting options for the energy frontier machine in the post-LHC era - is its interaction region (IR). Designs of its optics, magnets and machine-detector interface are strongly interlaced and iterative. As a result of recent comprehensive studies, consistent solutions for the 1.5 TeV c.o.m. MC IR have been found and are described here. To provide the required momentum acceptance, dynamic aperture and chromaticity, innovative approach was used for the IR optics. Conceptual designs of large-aperture high-field dipole and high-gradient quadrupole magnets based on Nb₃Sn superconductor were developed and analyzed in terms of the operation margin, field quality, mechanics, coil cooling and quench protection. Shadow masks in the interconnect regions and liners inside the magnets are used to mitigate unprecedented dynamic heat deposition due to muon decays (~1 kW/m). It is shown that an appropriately designed machine-detector interface with sophisticated shielding in the detector has a potential to substantially suppress the background rates in the MC detector.

Slides MOODN6 [1.233 MB]

MOP007

The Development Status of Compact Linear Accelerator in Korea

plasma, ECRIS, ECR, ion

112

B.S. Lee, M. Won
Korea Basic Science Institute, Busan, Republic of Korea
J.-K. Ahn
Pusan National University, Pusan, Republic of Korea
T. Nakagawa
RIKEN Nishina Center, Wako, Japan

Funding: This work was supported by KBSI D30300 to M.S Won
The establishment of a compact linear accelerator is in progress by Korea Basic Science Institute. The main capability of this facility is the production of multiply ionized metal clusters and the generation of intense beams of highly charged ions for material, medical and nuclear physical research. To generate the intense beam of highly charged ions, we will develop an Electron Cyclotron Resonance Ion Source (ECRIS) using 28GHz microwaves. For this ECRIS, the designing of a superconducting magnet, microwave inlet, beam extraction, and plasma chamber were in progress. A superconducting magnet system have also being developed. In this presentation, I report the current status of our compact linear accelerator development and future plan.

MOP234

Beam Position and Phase Monitors for the LANSCE Linac

linac, controls, monitoring, instrumentation

548

R.C. McCrady, J.D. Gilpatrick, J.F. Power
LANL, Los Alamos, New Mexico, USA

Funding: This work is supported by the US Department of Energy under contract DE-AC52-06NA25396
New beam-position and phase monitors are under development for the linac at the Los Alamos Neutron Science Center. Transducers have been designed and are being fabricated. We are considering many options for the electronic instrumentation to process the signals and provide position and phase data with the necessary precision and flexibility to serve the various required functions. We’ll present the requirements of the system and the various options under consideration for instrumentation along with the advantages and shortcomings of these options.

MOP256

Upgrading the Data Acquisition and Control System of the LANSCE LINAC

controls, linac, EPICS, proton

588

D. Baros
LANL, Los Alamos, New Mexico, USA

Funding: This work has benefited from the use of the LANSCE at LANL. This facility is funded by the US DOE and operated by LANS for NSSA under Contract DE-AC52-06NA25396.
Los Alamos National Laboratory LANL is in the process of upgrading the control system for the Los Alamos Neutron Science Center (LANSCE) linear accelerator. The 38 year-old data acquisition and control equipment is being replaced with COTS hardware. An overview of the current system requirements and how the National Instruments cRIO system meets these requirements will be given, as well as an update on the installation and operation of a prototype system in the LANSCE LINAC.
LANL Release Number: LA-UR 10-06605

MOP272

Radiation Dose Level in the SSRF during Normal Operation

radiation, monitoring, storage-ring, injection

615

X.J. Xu, P. Fei, R. Qin, W. Shen, X. Xia, D. Zhang, J.Z. Zhou
SINAP, Shanghai, People's Republic of China

Shanghai Synchrotron Radiation Facility (SSRF) has been commissioned since December 2007, and has been formally operated since May 2009. In order to ensure the radiation safety for staff members and publics, the radiation levels of the workplace, the environment and the staff are monitored through a real-time network of gamma and neutron monitors as well as through TLD passive dosimeters. This paper reports the results of the radiation monitoring. From these results, we found that the annual dose equivalents were good to meet the management values of SSRF.

MOP288

Progress Report on Development of the RING Cavity for Laser-based Charge Stripping of Hydrogen Ions

laser, radiation, ion, recirculation

657

R. Tikhoplav
RadiaBeam, Santa Monica, USA
I. Jovanovic
Penn State University, University Park, Pennsylvania, USA

Charge stripping of hydrogen ions is the first stage of any high intensity proton accelerator. To achieve higher-charge proton sources, the stripping efficiency must be improved, especially in the context of the Spallation Neutron Source at Oak Ridge National Laboratory. A method based on laser-ion interaction has a great potential for increasing efficiency. The approach of this proposed project is to design a laser cavity based on the Recirculation Injection by Nonlinear Gating (RING) technique. This paper reports on the progress of the development of the RING cavity.

TUP003

Beam Stop of Spiral2 Facility: Activation and Residual Dose Rate Calculations

simulation, photon, factory, shielding

811

A. Mayoral, M. García, D. López, F. Ogando, J. Sanz, P. Sauvan
UNED, Madrid, Spain

Funding: *SPIRAL 2 Preparatory Phase. European Strategy Forum on Research Infrastructures. Seventh Framework Programme Ref 212692 **The Spanish Ministery of Science and Innovation. Project ENE2009-07572
SPIRAL2 facility is expected to produce 5mA of deuterons at 40 MeV. A beam dump device (BD) has been designed to stop the beam. In this paper we assess the residual dose rates (RDR) in the BD room during beam-off phases. MCNPX was used to deal with deuterons transport and production and transport of secondary neutrons. Deuteron and neutron induced activation were computed using ACAB* and EAF2007. Decay gammas were transported using MCNPX to compute RDR. Dose rates at cooling times up to one year are presented, showing that it is mainly due to BD copper induced activation. The uncertainties in the results can be attributed to: i) the reliability of the d-Cu activation cross sections reactions, ii) the computational approach used to assess the neutron source. The troublesome radioisotopes from d-Cu and their formation reactions were identified. EAF2007 cross sections for these reactions were compared with the available experimental data. Regarding the computational approach to determine the neutron source from d-Cu interactions two options were used: i) built-in nuclear models of MCNPX, ii) TENDL** and MCUNED***. The available experimental data were used for benchmarking.
* J. Sanz et al. ACAB. User’s manual NEA-1839 (2009)
** A.J. Koning et al. TENDL2008 http://www.talys.eu/tendl-2008/
*** P.Sauvan et al. Nucl. Instr.and Meth. A 614 (2010)3 323-330.

TUP004

GEANT4 Modelling of Heat Deposition into the ISIS Muon Target

target, proton, ion, simulation

814

A. Bungau, R. Cywinski
University of Huddersfield, Huddersfield, United Kingdom
R.J. Barlow
Cockcroft Institute, Warrington, Cheshire, United Kingdom
C. Bungau
Manchester University, Manchester, United Kingdom
P.J.C. King, J.S. Lord
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom

The energy deposition on the ISIS muon target and the temperature profiles are analysed in this paper. The thermal modelling is performed using the GEANT4 Monte Carlo code. Heat deposition patterns are also simulated for alternative target geometries. Energy deposition in the collimators is also discussed.

TUP146

Large Aperture Quadrupole Magnets for ISIS TS-1 and TS-2

quadrupole, dipole, target, proton

1103

S.M. Gurov, A.M. Batrakov, M.F. Blinov, F.A. Emanov, V.V. Kobets, V.A. Polukhin, A.S. Tsyganov, P. Vobly, T.A. Yaskina
BINP SB RAS, Novosibirsk, Russia
S.J.S. Jago, J. Shih, S.F.S. Tomlinson
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

The ISIS pulsed neutron and muon source at the Rutherford Appleton Laboratory has two target stations TS-1 and TS-2. Budker Institute of Nuclear Physics developed, produced and delivered seven type Q13 quadrupole magnets with an aperture diameter of 310 mm for TS-2 beam transfer line. Later an additional three quadrupoles with integrated dipole coils were developed and delivered to ISIS TS1. To improve the field quality across the full current range a special pole profile and end chamfer were designed using the MERMAID code. The magnetic field map was measured by a set of Hall probes. Moreover, BINP produced a rotating coil with radius 120 mm for field quality measurements.

TUP179

Energy Deposition within Superconducting Coils of a 4 MW Target Station

target, shielding, simulation, factory

1166

X.P. Ding
UCLA, Los Angeles, California, USA
J.J. Back
University of Warwick, Coventry, United Kingdom
R.C. Fernow, H.G. Kirk, N. Souchlas
BNL, Upton, Long Island, New York, USA
K.T. McDonald
PU, Princeton, New Jersey, USA
R.J. Weggel
Particle Beam Lasers, Inc., Northridge, California, USA

Funding: Work Supported by the United States Department of Energy, Contract No. DE-AC02-98CH10886.
A study of energy deposition within superconducting coils of a 4 MW target station for a neutrino factory or muon collider is presented. Using the MARS code, we simulate the energy deposition within the environment surrounding the target. The radiation is produced by interactions of intense proton beams with a free liquid mercury jet. We study the influence of different shielding materials and shielding configurations on the energy deposition in the superconducting coils of the target/capture system. We also examine energy depositions for alternative configurations that allow more space for shielding, thus providing more protection for the superconducting coils.

TUP275

SNS Linac Modulator Operational History and Performance

linac, high-voltage, klystron, monitoring

1340

V.V. Peplov, D.E. Anderson, R.I. Cutler, M. Wezensky
ORNL, Oak Ridge, Tennessee, USA
J.D. Hicks, R.B. Saethre
ORNL RAD, Oak Ridge, Tennessee, USA

Fourteen High Voltage Converter Modulators (HVCM) were initially installed at the Spallation Neutron Source Linear Accelerator (SNS Linac) at the Oak Ridge National Laboratory in 2005. A fifteenth HVCM was added in 2009. Each modulator provides a pulse of up to 140 kV at a maximum width of 1.35 msec. Peak power level is 11 MW with an 8% duty factor. The HVCM system must be available for neutron production (NP) 24/7 with the exception being two, 6-week maintenance periods per year. HVCM reliability is one of the most important factors to maximize Linac availability and achieve SNS performance goals. During the last few years several modifications have been implemented to improve the overall system reliability. This paper presents operational history of the HVCM systems and examines failure mode statistical data since the modulators began operating at 60 Hz. System enhancements and upgrades aimed at providing long term reliable operation with minimal down time are also discussed in the paper.

WEODS2

High-Power Targets: Experience and R&D for 2 MW

target, radiation, proton, simulation

1496

P. Hurh
Fermilab, Batavia, USA
O. Caretta, T.R. Davenne, C.J. Densham, P. Loveridge
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
N. Simos
BNL, Upton, Long Island, New York, USA

High-power particle production targets are crucial elements of future neutrino and other rare particle beams. Fermilab plans to produce a beam of neutrinos (LBNE) with a 2.3 MW proton beam (Project X). Any solid target is unlikely to survive for an extended period in such an environment - many materials would not survive a single beam pulse. We are using our experience with previous neutrino and antiproton production targets, along with a new series of R&D tests, to design a target that has adequate survivability for this beamline. The issues considered are thermal shock (stress waves), heat removal, radiation damage, radiation accelerated corrosion effects, physics/geometry optimization and residual radiation.

WEP010

Design of the Bilbao Accelerator Low Energy Extraction Lines

quadrupole, linac, dipole, DTL

1519

Z. Izaola, I. Rodríguez
ESS-Bilbao, Zamudio, Spain
E. Abad, I. Bustinduy, R. Martinez, F. Sordo Balbin, D. de Cos
ESS Bilbao, Bilbao, Spain
D.J. Adams, S.J.S. Jago
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
F.J. Bermejo
Bilbao, Faculty of Science and Technology, Bilbao, Spain
V. Etxebarria, J. Portilla
University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain

Funding: European Spallation Source - Bilbao
The ESS-Bilbao linac will accelerate H+ and H− beams up to 50 MeV, which need to be transported to three laboratories, where different types of experiments will be conducted. This paper reports on the preliminary design of the transfer line, which is mainly performed based on beam dynamics simulations.

WEP224

Operational Status and Life Extension Plans for the Los Alamos Neutron Science Center (LANSCE)

proton, linac, target, scattering

1906

J.L. Erickson, D. Rees
LANL, Los Alamos, New Mexico, USA

Funding: Work supported by the U. S. Department of Energy, National Nuclear Security Administration, Contract No. DE-AC52-06NA25396 – Publication Release LA-UR- 10-06556
The Los Alamos Neutron Science Center (LANSCE) accelerator and beam delivery complex generates the proton beams that serve three neutron production sources, a proton radiography facility and a medical and research isotope production facility. The recent operating history of the facility, including both achievements and challenges, will be reviewed. Plans for performance improvement will be discussed, together with the underlying drivers for the ongoing LANSCE Linac Risk Mitigation project. The details of this latter project will be discussed. The status of accelerator-related plans for the MaRIE Project (Matter-Radiation Interactions in Extremes Experimental Project) will also be discussed. Taken together, the LANSCE Linac Risk Mitigation Project and the MaRIE initiative demonstrate a commitment to investment in the ongoing operation and improvement of the facility, and a resurgent interest in the spectrum of science accessible at LANSCE. These plans will assure continued facility operational and scientific vitality well beyond 2020.

WEP271

Development of a Permanent-Magnet Microwave Ion Source for a Sealed-Tube Neutron Generator

ion, ion-source, plasma, ECR

1984

O. Waldmann, B.A. Ludewigt
LBNL, Berkeley, California, USA

Funding: Supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
A microwave ion source has been designed and constructed for use with a sealed-tube, high-yield neutron generator. When operated with a tritium-deuterium gas mixture the generator will be capable of producing 5 · 10¹¹ n/s in non-proliferation applications. Microwave ion sources are well suited for such a device because they can produce high extracted beam currents with a high atomic fraction at low gas pressures of 0.2 − 0.3 Pa required for sealed tube operation. The magnetic field strength for achieving electron cyclotron resonance (ECR) condition, 87.5 mT at 2.45 GHz microwave frequency, was generated and shaped with permanent magnets surrounding the plasma chamber and a ferromagnetic plasma electrode. This approach resulted in a compact ion source that matches the neutron generator requirements. The needed proton-equivalent extracted beam current density of 40 mA/cm² was obtained at moderate microwave power levels of ∼ 400W. Results on magnetic field design, pressure dependency and atomic fraction measured for different wall materials are presented.

THOAS3

Status of the Oak Ridge Spallation Neutron Source (SNS) RF Systems

klystron, controls, linac, rfq

2050

T.W. Hardek, M.T. Crofford, Y.W. Kang, M.F. Piller, A.V. Vassioutchenko
ORNL, Oak Ridge, Tennessee, USA
S.W. Lee, M.E. Middendorf
ORNL RAD, Oak Ridge, Tennessee, USA

The SNS has been delivering production neutrons for five years with first beam delivered to the neutron target at the end of April 2006. On September 18, 2009 SNS officially reached 1 megawatt of beam on target marking the achievement of a decades-old dream of providing a U.S. megawatt class pulsed spallation source. The SNS is now routinely delivering 1 megawatt of beam power to the neutron target at over 85 percent of the scheduled beam time. The present effort is aimed at increasing availability eventually to 95 percent and gradually increasing the intensity to the 1.4 megawatt design level. While the RF systems have performed well since initial installation some improvements have been implemented. This paper provides a review of the SNS RF Systems, an overview of the performance of the various components and a detailed review of RF related issues addressed over the past several years.

Slides THOAS3 [2.759 MB]

THOCN4

High-Power Options for LANSCE

DTL, linac, proton, klystron

2107

R.W. Garnett, E.J. Pitcher, D. Rees, L. Rybarcyk, T. Tajima
LANL, Los Alamos, New Mexico, USA

Funding: This work is supported by the U. S. Department of Energy Contract DE-AC52-06NA25396.
The LANSCE linear accelerator at Los Alamos National Laboratory has a long history of successful beam operations at 800 kW. We have recently studied options for restoration of high-power operations including schemes for increasing the performance to multi-MW levels. In this paper we will discuss the results of this study including the present limitations of the existing accelerating structures at LANSCE, and the high-voltage and RF systems that drive them. Several plausible options will be discussed and a preferred option will be presented that will enable the first in a new generation of scientific facilities for the materials community. The emphasis of this new facility is "Matter-Radiation Interactions in Extremes" (MaRIE) which will be used to discover and design the advanced materials needed to meet 21st century national security and energy security challenges.

Slides THOCN4 [2.903 MB]

THP009

Collimator Design of 15 MeV Linear Accelerator Based Thermal Neutron Source for Radiography

target, electron, simulation, linac

2154

B.J. Patil, V.N. Bhoraskar, S.D. Dhole
University of Pune, Pune, India
S.T. Chavan, R. Krishnan, S.N. Pethe
SAMEER, Mumbai, India
A.J. Patil
DANA, Pune, India

Neutron Radiography is a powerful non-destructive testing technique used for the analysis of objects which are widely used in security, medical, nuclear and industrial applications. Optimization of the thermal neutron radiography facility has been carried out using 15 MeV LINAC based neutron source. In this case, a neutron collimator has been designed along with g-n target, moderator, reflector and shielding. The g-n target has been optimized based on their photonuclear threshold. The moderating properties have been studied for few light elements to optimize best suitable moderator for radiography system. The major part of the design was to optimize the collimator for neutron beam which decides quality of the image given. To get best values of collimator parameters such as collimation ratio, gamma content, neuron flux, cadmium ratio, beam uniformity, etc. a FLUKA simulation was carried out. The collimator has been optimized with cadmium lining square cone to capture the scattered thermal neutrons and the collimation ratio to L/D=18. The neutron flux of the optimized facility obtained at the object plane is 1.0·10⁺⁵ n/(cm²-sec¹) and neutron to gamma ratio is 1.0·10⁺⁵ n/(cm²-mR¹).

THP029

Temperature and Optimize Design of Beam Window in the Accelerator

proton, target, vacuum, radiation

2175

J.J. Tian, H. Hao, G. Liu, H.L. Luo, X.Q. Wang, H.L. Wu
USTC/NSRL, Hefei, Anhui, People's Republic of China

Careful evaluation of the heat-transfer and corresponding problems is important in the beam window in the design and operation of Accelerator Driven sub-critical System (ADS). Using the Monte-Carlo code Fluka, we studied the energy deposition of the beam window in high power proton accelerator. The temperature distribution of the beam window is calculated in presence of the coolant. The process of computation for various materials will be introduced, and an optimized design scheme is given. The results suggest that some measures could be used to reduce the damage to the beam window, such as dividing current into branch currents, expanding the bunch or using beryllium as the material of the beam window, et al.

THP030

GEANT4 Studies of the Thorium Fuel Cycle

proton, simulation, target, scattering

2178

C. Bungau
Manchester University, Manchester, United Kingdom
R.J. Barlow
UMAN, Manchester, United Kingdom
A. Bungau, R. Cywinski
University of Huddersfield, Huddersfield, United Kingdom

Thorium “fuel” has been proposed as an alternative to uranium fuel in nuclear reactors. New GEANT4 developments allow the Monte Carlo code to be used for the first time in order to simulate the time evolution of the concentration of isotopes present in the Thorium fuel cycle. A full study is performed in order to optimise the production of Uranium-233 starting with "pure" Thorium fuels, leading to levels of Uranium-233 which ensure the operation of the nuclear reactor in a regime close to criticality.

THP034

Accelerators for Subcritical Molten Salt Reactors

target, linac, proton, SRF

2181

R.P. Johnson
Muons, Inc, Batavia, USA
C. Bowman
ADNA, Los Alamos, New Mexico, USA

Funding: Supported in part by Accelerator Technologies Inc.
Accelerator parameters for subcritical reactors that have been considered in recent studies * are based on using solid nuclear fuel much like that used in all operating critical reactors as well as the thorium-burning accelerator-driven energy amplifier ** proposed by Rubbia et al. An attractive alternative reactor design that used molten salts was experimentally studied at ORNL in the 1960s, where a critical molten salt reactor was successfully operated using enriched U235 or U233 tetrafluoride fuels ***. These experiments give confidence that an accelerator-driven subcritical molten salt reactor will work as well or better than conventional reactors, having better efficiency due to their higher operating temperature and having the inherent safety of subcritical operation. Moreover, the requirements to drive a molten salt reactor are considerably relaxed compared to a solid fuel reactor, especially regarding accelerator reliability and spallation neutron targetry, to the point that the required technology exists today.
* http://www.er.doe.gov/hep/files/pdfs/ADSWhitePaperFinal.pdf
** http://wikipedia.org/wiki/Energy_amplifier
*** Paul N. Haubenreich and J. R. Engel, Nuc. Apps & Tech, 8, Feb. 1970

THP037

Design of an e-γ Converter for a 10 MeV Electron Beam

target, electron, photon, linac

2184

L. Auditore, D. Loria, E. Morgana
INFN - Gruppo Messina, S. Agata, Messina, Italy
L. Auditore, R.C. Barnà, A. Trifirò, M. Trimarchi
Università di Messina, Messina, Italy
G. Di Bella
Università di Messina, Facoltà di Ingegneria, Messina, Italy

In the last years, the INFN-Gruppo Collegato di Messina has designed and setup an x-ray source based on the 5 MeV electron linac hosted at the Dipartimento di Fisica - Università di Messina. In the meanwhile, and in the framework of an European funding, the group has setup the Centro Ricerche at Villafranca Tirrena (Messina, Italy) which holds a 10 MeV electron linac and which is, at the moment, mainly devoted to industrial Radiation Processing applications. Nevertheless, to the aim to provide also x-ray beams, an e-g converter has been designed by means of the MCNP4C2 simulation code and optimized for a 10 MeV electron beam. A wide investigation has been performed to choose material and thickness for the e-g converter in order to provide the highest x-ray yield. Then, angular distribution and energy spectrum have been simulated to characterize the produced bremsstrahlung beam. Also the target activation has been investigated. Finally, thermal analysis has been performed using a finite element model code, Deform 2D, to choose the definitive mechanical settings of the e-g converter.

THP048

Radiation and Thermal Analysis of Production Solenoid for Mu2e Experimental Setup

solenoid, target, proton, radiation

2208

V.S. Pronskikh, V. Kashikhin, N.V. Mokhov
Fermilab, Batavia, USA

The Muon-to-Electron (Mu2e) experiment at Fermilab, will seek the evidence of direct muon to electron conversion that cannot be explained by the Standard Model. An 8 GeV 25 kW proton beam will be directed onto a gold target inside a large-bore superconducting Production Solenoid (PS) with the peak field on the axis of ~5T. The negative muons resulting from the pion decay will be captured in the PS aperture and directed by an S-shaped Transport Solenoid towards the stopping target inside the Detector Solenoid. In order for the superconducting magnets to operate reliably and with a sufficient safety margin, the peak neutron flux entering the coils must be reduced by 3 orders of magnitude that is achieved by means of a sophisticated absorber placed in the magnet aperture. The proposed absorber, consisting of W and Cu parts, is optimized for the performance and cost. Results of MARS15 of energy deposition and radiation analysis are reported. The results of the PS magnet thermal analysis, coordinated with the coil cooling scheme, are reported as well for the selected absorber design.

THP053

The New Approximation of Dose Attenuation Curve in Concrete

shielding, ion, heavy-ion, target

2217

M. Petrichenkov, V.Ya. Chudaev
BINP SB RAS, Novosibirsk, Russia

The analytical approach in shielding calculations is simple and fast method for quick estimations. But it provides less accuracy than Monte-Carlo one. Often the exponential attenuation of dose in shielding is considered. But also it is necessary to take into account the dose increase in the first layers of shielding due to initial accumulation of neutrons. The new approximation of dose attenuation curve in concrete is offered for quick analytical estimations of shielding of hadron accelerators. It allows to make fast estimation of shielding thickness enough correctly.

THP087

G4Beamline and MARS Comparison for Muon Collider Backgrounds

collider, background, electron, simulation

2297

M.A.C. Cummings, S.A. Kahn
Muons, Inc, Batavia, USA
D. Hedin, A.O. Morris
Northern Illinois University, DeKalb, Illinois, USA
J.F. Kozminski
Lewis University, Romeoville, Illinois, USA

Funding: Supported in part by SBIR Grant DE-SC0005447
Technological innovations in recent years have revived interest in muon colliders as the next generation energy frontier machine. The biggest challenge for muon colliders is that muons decay. Advances in muon cooling technology will make the focussing and acceleration of muons to TeV energies possible. The challenge for the detectors in such machines is overcoming the large backgrounds from muon decays in the colliding ring lattice that will inundate the interaction region (IR) and will make triggering and data reconstruction a challenge. Developing simulation tools that can reliably model the environment of the muon collider IR will be critical to physics analyses. We will need to expand the capabilities of current programs and use them to benchmark and verify results against each other. Here we are comparing an emerging capabiligy of G4beamline, an interface for physicists to GEANT4 code, with MARS, a mature program for particle fluences, in developing code for muon collider background studies

THP088

Beam Induced Detector Backgrounds at a Muon Collider

collider, background, shielding, electron

2300

S.A. Kahn, M.A.C. Cummings, T.J. Roberts
Muons, Inc, Batavia, USA
D. Hedin, A.O. Morris
Northern Illinois University, DeKalb, Illinois, USA
J.F. Kozminski
Lewis University, Romeoville, Illinois, USA

Funding: Supported in part by SBIR Grant DE-SC0005447
Muon colliders are considered to be an important future energy frontier accelerator. It is possible to build a large muon collider as a circular machine, even at multi-TeV energies, due to the greatly reduced synchrotron radiation expected from muons. In addition to the same physics processes present in an electron collider, a muon collider will have the potential to produce s-channel resonances such as the various Higgs states at an enhanced rate. For a muon collider with 750 GeV/c mu+ and mu- with 10¹² mu per bunch we would expect 4.3x10⁵ muon decays per meter. These muon decays will produce very energetic off momentum electrons that can produce detector backgrounds that can affect the physics. These backgrounds include electrons from muon decays, synchrotron radiation from the decay electrons, hadrons produced by photo-nuclear interactions, coherent and incoherent beam-beam pair production and Bethe-Heitler muon production. In this paper we will discuss these processes and calculate particle fluxes into the detector volume from these background processes.

THP090

Physics Validation of Monte Carlo Simulations for Detector Backgrounds at a Muon Collider

simulation, electron, background, collider

2303

A.O. Morris, D. Hedin
Northern Illinois University, DeKalb, Illinois, USA
M.A.C. Cummings, S.A. Kahn, T.J. Roberts
Muons, Inc, Batavia, USA
J.F. Kozminski
Lewis University, Romeoville, Illinois, USA

Muon colliders are considered to be an important future energy-frontier accelerator. A muon collider could be built as a circular accelerator into the TeV energy range as a result of the reduced synchrotron radiation expected from the larger rest mass of muons. For a muon collider with 750 GeV μ+ and μ- with 10¹2 μ per bunch, it can be expected that there would be 4.3×10⁵ muon decays per meter per beam. These decays will produce very energetic off-momentum electrons that can produce detector backgrounds that can affect the physics. The main backgrounds include electrons from muon decays, synchrotron radiation from the decay electrons, hadrons produced by photonuclear interactions, coherent and incoherent beam-beam pair-production, and Bethe-Heitler muon production. In this paper we will discuss the simulation results in terms of observed physics processes in G4Beamline.

FROAN1

The European Spallation Source

linac, target, proton, cryomodule

2549

S. Peggs, H. Danared, M. Eshraqi, H. Hahn, A. Jansson, M. Lindroos, A. Ponton, K. Rathsman, G. Trahern
ESS, Lund, Sweden
S. Bousson
IPN, Orsay, France
R. Calaga
BNL, Upton, Long Island, New York, USA
G. Devanz, R.D. Duperrier
CEA/DSM/IRFU, France
J. Eguia
Fundación TEKNIKER, Eibar (Gipuzkoa), Spain
S. Gammino
INFN/LNS, Catania, Italy
S.P. Møller
ISA, Aarhus, Denmark
C. Oyon
SPRI, Bilbao, Spain
R.J.M.Y. Ruber
Uppsala University, Uppsala, Sweden
T. Satogata
JLAB, Newport News, Virginia, USA

The European Spallation Source (ESS) is a 5 MW, 2.5 GeV long pulse proton linac, to be built and commissioned in Lund, Sweden. The Accelerator Design Update (ADU) project phase is under way, to be completed at the end of 2012 by the delivery of a Technical Design Report. Improvements to the 2003 ESS design will be summarised, and the latest design activities will be presented.

Slides FROAN1 [1.650 MB]

FROCB2

Science with Light and Neutron Sources

scattering, synchrotron, electron, photon

2596

S.K. Sinha
UCSD, La Jolla, California, USA

In recent years there has been great progress in the development of accelerator-based light and neutron sources. The speaker will give an overview of the exciting new opportunities provided by the enhanced source capabilities available at present and future facilities.
Speaker Sunhil Sinha, a professor in the Physics Department of the University of California at San Diego

Slides FROCB2 [26.588 MB]