HB2012 - List of Keywords (ion)

Paper	Title	Other Keywords	Page
MOI1B01	High Intensity Issues at FAIR	emittance, heavy-ion, synchrotron, ion-source	11
	O.K. Kester GSI, Darmstadt, Germany O.K. Kester IAP, Frankfurt am Main, Germany
	Funding: Supported by the BMBF and Helmholtz International Center for FAIR The facility for antiproton and ion research - FAIR - will produce secondary beams of unprecedented intensities [1]. In order to produce such intense secondary beams and to provide intense beams for the CBM [2] and APPA [3] collaboration, primary heavy ion beams of highest intensities will be required. The main driver accelerator of FAIR will be the SIS100 synchrotron. The GSI heavy ion accelerator facility will be the injector of ion beams for SIS100. In order to reach the final intensities above 10¹¹ ions per cycle, the injector chain has to be modified accordingly and the SIS100 has to be tailored to the needs. Therefore an intensity upgrade program of the GSI accelerator facility has been started, which comprises improvements of ion sources, of the injector linacs and of the heavy ion synchrotron SIS18. In addition, high energy beam transport and the SIS100 need to have a dedicated design, in order to handle beam losses. The issues of the upgrade programme and of the SIS100 design will be addressed. [1] FAIR Green Paper- The Modularized Start Version, Oct.2009 [2] B.Friman et al.,The CBM physics Book, Series: Lecture Notes in Physics, Vol.814,2011 [3] http://www.fair-center.de/de/oeffentlichkeit/experimenteprogramm/appa-physics.html
	Slides MOI1B01 [15.662 MB]

MOI1C03	Beam Loss Mechanisms in High Intensity Linacs	linac, DTL, proton, optics	36
	M.A. Plum ORNL, Oak Ridge, Tennessee, USA
	Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725. Beam loss is a critical issue in high intensity linacs, and much work is done during both the design and operation phases to keep the loss down to manageable levels. Linacs for H⁻ ion beams have many more loss mechanisms compared to H⁺ (proton) linacs. Interesting H⁻ beam loss mechanisms include residual gas stripping, H⁺ capture and acceleration, field stripping, and intra-beam stripping (IBSt). Beam halo formation, and ion source or RF turn on/off transients, are examples of beam loss mechanisms that are common for both H⁺ and H⁻ accelerators. The IBSt mechanism has recently been characterized at the Oak Ridge Spallation Neutron Source, and we have found that it accounts for most of the loss in the superconducting linac. In this paper we will detail the IBSt measurements, and also discuss the other beam loss mechanisms that are important for high intensity linacs.
	Slides MOI1C03 [5.588 MB]

MOP205	Intense Heavy-Ion Bunches in Dual-harmonic RF Systems	impedance, factory, space-charge, synchrotron	51
	M. Mehler, O. Chorniy GSI, Darmstadt, Germany O. Boine-Frankenheim TEMF, TU Darmstadt, Darmstadt, Germany O.K. Kester IAP, Frankfurt am Main, Germany
	For the synchrotron's SIS-18 and SIS-100 (FAIR) a dual-harmonic RF system with the harmonic numbers h1=2, h2=4 and h1=10, h2=20 respectively is planned. Such systems flatten the bunch form and increase the bunching factor Bf therefore reducing the transverse space charge force. For high currents cavity beam loading and potential-well distortion will deform the flattened bunch shape and lead to phase shifts. Optimized settings for the difference between the two RF phases and for the synchronous phase of the main RF harmonic are an option to reduce these effects. In this contribution we will analyse further aspects of the matched bunch distribution, possible instabilities of the obtained distribution will be discussed and results of machine experiments in SIS-18 will be presented.

MOP245	Quench Tests at the Large Hadron Collider with Collimation Losses at 3.5 Z TeV	proton, collimation, cryogenics, insertion	157
	S. Redaelli, R.W. Aßmann, G. Bellodi, K. Brodzinski, R. Bruce, F. Burkart, M. Cauchi, D. Deboy, B. Dehning, E.B. Holzer, J.M. Jowett, E. Nebot Del Busto, M. Pojer, A. Priebe, A. Rossi, M. Sapinski, M. Schaumann, R. Schmidt, M. Solfaroli Camillocci, G. Valentino, R. Versteegen, J. Wenninger, D. Wollmann, M. Zerlauth CERN, Geneva, Switzerland L. Lari IFIC, Valencia, Spain
	The Large Hadron Collider (LHC) has been operating since 2010 at 3.5 TeV and 4.0 TeV without experiencing quenches induced by losses from circulating beams. This situation might change at 7 TeV where the reduced margins in the superconducting magnets. The critical locations are the dispersion suppressors (DSs) at either side of the cleaning and experimental insertions, where dispersive losses are maximum. It is therefore crucial to understand in detail the quench limits with beam loss distributions alike those occurring in standard operation. In order to address this aspect, quench tests were performed by inducing large beam losses on the primary collimators of the betatron cleaning insertion, for proton and lead ion beams of 3.5 Z TeV, to probe the quench limits of the DS magnets. Losses up to 500 kW were achieved without quenches. The measurement technique and the results obtained are presented, including observations of heat loads in the cryogenics system.

TUO1A04	Plasma Traps for Space-charge Studies: Status and Perspectives	plasma, resonance, laser, quadrupole	235
	H. Okamoto, K. Fukushima, H. Higaki, K. Ito, K. Moriya, T. Okano, S. Yamaguchi HU/AdSM, Higashi-Hiroshima, Japan M. Endo Hiroshima University, Higashi-Hiroshima, Japan A. Mohri Kyoto University, Graduate School of Human and Environmental Studies, Kyoto, Japan
	Funding: Work supported in part by a Grant-in-Aid for Scientific Research, Japan Society for the Promotion of Science. The beam physics group of Hiroshima University has developed non-neutral plasma traps dedicated solely to a wide range of beam dynamics studies. Those unique experimental tools approximately reproduce, in the laboratory frame, a many-body Coulomb system that is physically equivalent to a charged-particle beam observed in the center-of-mass frame. We have designed and constructed two different types of traps that employ either a radio-frequency electric quadrupole field or an axial magnetic field for transverse particle confinement. The former type is commonly referred to as "linear Paul trap" and the latter as "Penning trap". At present, three Paul traps and one Penning trap are operational while a new Penning trap for beam halo experiments is under construction. Each of these compact experimental facilities consists of a trap, many power supplies, a vacuum system, a computer control system, etc., and is called "S-POD (Simulator for Particle Orbit Dynamics)". S-POD is particularly useful for fundamental studies of high-intensity and high-brightness hadron beams. We here report on recent experimental outputs from S-POD and also briefly describe some future plans.
	Slides TUO1A04 [7.790 MB]

TUO3A02	Status and Results of the UA9 Crystal Collimation Experiment at the CERN-SPS	collimation, proton, target, vacuum	245
	S. Montesano, W. Scandale CERN, Geneva, Switzerland
	The UA9 experimental setup was installed in the CERN-SPS in 2009 to investigate the feasibility of the halo collimation assisted by bent crystals. Two-millimeter-long silicon crystals, with bending angles of about 150 microrad, are used as primary collimators instead than a standard amorphous target. Studies are performed with stored beams of protons and lead ions at 270 Z GeV. The loss profile is precisely measured in the area near to the crystal-collimator setup and in the downstream dispersion suppressor. A strong correlation of the losses in the two areas is observed and a steady reduction of dispersive losses is recorded at the onset of the channeling process. The loss map in the accelerator ring is is also reduced. These observations strongly support our expectation that the coherent deflection of the beam halo by a bent crystal should enhance the collimation efficiency in hadron colliders, such as LHC. for the UA9 Collaboration
	Slides TUO3A02 [5.936 MB]

TUO1B05	The Design and Commissioning of the Accelerator System of the Rare Isotope Reaccelerator - ReA3 at Michigan State University	cryomodule, rfq, target, linac	269
	X. Wu, B. Arend, C. Compton, A. Facco, M.J. Johnson, D. Lawton, D. Leitner, F. Montes, S. Nash, J. Ottarson, G. Perdikakis, J. Popielarski, J.A. Rodriguez, M.J. Syphers, W. Wittmer, Q. Zhao NSCL, East Lansing, Michigan, USA
	Funding: This material is based upon work supported by the U.S. Department of Energy Office of Sciences under Cooperative Agreement DE-SC0000661 The National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University (MSU) is currently constructing its new rare isotope reaccelerator facility: ReA3, which will provide unique low-energy rare isotope beams by stopping fast rare isotopes in gas stopping systems, boosting the charge state in an Electron Beam Ion Trap (EBIT) and reaccelerating them in a superconducting linac. The rare isotope beams will be producted intially by Coupled Cyclotron Facility (CCF) at NSCL and later by Facility for Rare Isotope Beams (FRIB), currently being designed and constructed at MSU. The accelerator system consists of a Low Energy Beam Transport (LEBT), a room temperature RFQ and a linac utilizing superconducting QWRs. An achromatic High Energy Beam Transport (HEBT) will deliver the reaccelerated beams to the mutiple target stations. Beams from ReA3 will range from 3 MeV/u for heavy nuclei such as uranium to about 6 MeV/u for ions with A<50. The commissioning of the EBIT, RFQ and two cryomodules of the linac is currently underway. The ReA3 accelerator system design and status of commissioning will be presented.
	Slides TUO1B05 [6.046 MB]

TUO1C05	Measurements and Interpretation of the Betatron Tune Spectra of High Intensity Bunched Beam at SIS-18	space-charge, synchrotron, acceleration, injection	310
	R. Singh, O. Chorniy, P. Forck, R. Haseitl, W. Kaufmann, P. Kowina, K. Lang GSI, Darmstadt, Germany O. Boine-Frankenheim, R. Singh, T. Weiland TEMF, TU Darmstadt, Darmstadt, Germany
	The paper presents the status of the transverse tune measurements in the synchrotron SIS18 at GSI. Presently, there are two systems for tune measurements in operation in the SIS18, namely TOPOS (Tune, Orbit and POsition measurement System) and BBQ (Base Band tune measurement system). The first one is a digital system where the BPM signal is digitized and the bunch position is calculated numerically. The second system is an analog system, where the transverse bunch motion is detected using peak detector. Band limited noise and chirp excitations were used to excite the betatron oscillations. Measurements of the betatron tune spectra were done at injection energy at medium and high intensities. In the frequency spectra a number of peaks around the position of betatron tune were seen. The peaks can be attributed to different bunch head-tail modes which were observed in time domain. These modes were dependent on the beam intensity. In this paper we compare the tune spectra measured at high beam intensity with the theoretical model for the space charge affected head-tail modes.
	Slides TUO1C05 [1.315 MB]

WEO1B02	Optics Design Optimization for IBS Dominated Beams	emittance, optics, scattering, damping	386
	F. Antoniou, H. Bartosik, Y. Papaphilippou CERN, Geneva, Switzerland T. Demma LAL, Orsay, France N. Milas, A. Streun PSI, Villigen PSI, Switzerland M.T.F. Pivi SLAC, Menlo Park, California, USA
	Intra-beam scattering is a small angle multiple Coulomb scattering effect, leading to emittance growth. It becomes important for high brightness beams in low emittance lepton rings, but also hadron synchrotrons and ring colliders. Several theoretical models have been developed over the years, however, when the IBS becomes predominant, the divergence between the models becomes important. In addition, the theoretical models are based on the consideration of Gaussian beams and uncoupled transverse motion. Recently, two multi-particle tracking codes have been developed, in order to enable the understanding of the IBS influence on the beam distribution and the inclusion of coupling. The comparison between theoretical models in different lattices and different regimes is discussed here and the benchmarking of the theoretical models with the tracking codes is presented. Finally, first measurement results are presented in low emittance rings and hadron synchrotrons.
	Slides WEO1B02 [2.389 MB]

WEO3B01	FRIB Accelerator Beam Dynamics Design and Challenges	linac, target, solenoid, rfq	404
	Q. Zhao, A. Facco, F. Marti, E. Pozdeyev, M.J. Syphers, J. Wei, X. Wu, Y. Yamazaki, Y. Zhang FRIB, East Lansing, Michigan, USA
	Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661. The Facility for Rare Isotope Beams (FRIB) will be a new national user facility for nuclear science. This cw, high power, superconducting (SC), heavy ion driver linac consists of a frontend to provide various highly charged ions at 0.5 MeV/u, three SC acceleration segments connected by two 180° bending systems to achieve an output beam energy of ≥200 MeV/u for all varieties of stable ions, and a beam delivery system to transport multi-charge-state beams to a fragmentation target at beam power of up to 400 kW. The linac utilizes four types of low-beta resonators with one frequency transition from 80.5 to 322 MHz after Segment 1, where ion charge state(s) is boosted through a stripper at ≤20 MeV/u. The beam dynamics design challenges include simultaneous acceleration of multi-charge-state beams to meet beam-on-target requirements, efficient acceleration of high intensity, low energy heavy ion beams, limitation of uncontrolled beam loss to <1 W/m, accommodation of multiple charge stripping scenarios, etc. We present the recent optimizations on linac lattice, the results of end-to-end beam simulations with machine errors, and the simulation of beam tuning and fault conditions.
	Slides WEO3B01 [7.899 MB]

WEO3B02	Acceleration and Transportation of Multiple Ion Species at Ebis-based Preinjector	rfq, linac, booster, emittance	409
	D. Raparia BNL, Upton, Long Island, New York, USA
	A new heavy ion pre-injector at Brookhaven National Laboratory consist of an electron Beam Ion Source (EBIS), RFQ and IH Linac and a short transport line. This pre-injector provide any ion Helium to Uranium at energy of 2 MeV/u for Relativistic Heavy Ion Collider (RHIC) and the NASA Space Radiation Laboratory (NSRL). EBIS produces multiple charge states of an ion of interested. These charge states are accelerated through RFQ (300 keV/u) and IH Linac (2 MeV/u) and transported to booster. Charge desecration occurs just before the injection into the booster. This paper discusses implication of acceleration and transports of multiple charge state ions.
	Slides WEO3B02 [5.825 MB]

WEO3B03	PXIE at FNAL	rfq, cavity, kicker, diagnostics	414
	N. Solyak, C.M. Baffes, A.Z. Chen, Y.I. Eidelman, B.M. Hanna, S.D. Holmes, V.A. Lebedev, S. Nagaitsev, J.-F. Ostiguy, R.J. Pasquinelli, D.W. Peterson, L.R. Prost, G.W. Saewert, A. Saini, V.E. Scarpine, A.V. Shemyakin, D. Sun, V.P. Yakovlev Fermilab, Batavia, USA
	PXIE is the integrated systems test for the Project X frontend. It is expected to accelerate 1-2 mA CW beam up to 30 MeV. The major goal of the project is a validation of the Project X concept and elimination of technical risks. It is expected to be constructed in the period of 2012-2016. In presentation the conceptual design of the experimental test facility, lattice and beam dynamics studies will be discussed in details.
	Slides WEO3B03 [4.561 MB]

WEO3B04	RFQ Beam Dynamics Design for Large Science Facilities and Accelerator-Driven Systems	rfq, proton, bunching, linac	419
	C. Zhang IAP, Frankfurt am Main, Germany
	Serving as the front-end of large science facilities and Accelerator-Driven Systems (ADS), the Radio-Frequency Quadrupole (RFQ) accelerator usually needs to reach low beam losses, good beam quality, high reliability, and cost savings such design goals at high beam intensities. To address the challenges for modern RFQs, a special beam dynamics design technique characterized by a reasonable and efficient bunching process with balanced space-charge forces has been developed as an alternative to the classic Four-Section Procedure proposed by Los Alamos National Laboratory (LANL). In this paper, the design studies of some recent RFQ projects will be presented as examples.
	Slides WEO3B04 [3.698 MB]

WEO1C01	Effect of Self-consistency on Periodic Resonance Crossing	simulation, resonance, space-charge, synchrotron	429
	G. Franchetti GSI, Darmstadt, Germany
	In high intensity bunched beams resonance crossing gives rise to emittance growth and beam loss. Both these effects build up after many synchrotron oscillations. Up to now long term modeling have relied on frozen models neglecting the physics of self-consistency. We address here this issue and present the state of the art of simulations also applied to the SIS100.
	Slides WEO1C01 [3.657 MB]

WEO3C02	Collimation of Ion Beams	collimation, proton, scattering, heavy-ion	461
	I. Strašík, O. Boine-Frankenheim GSI, Darmstadt, Germany
	The SIS 100 synchrotron as part of the FAIR project at GSI will accelerate various beam species from proton to uranium. An important issue is to minimize uncontrolled beam losses using a collimation system. An application of the two-stage collimation concept, well established for proton accelerators, is considered for the fully-stripped ion beams. The two-stage system consists of a primary collimator (a scattering foil) and secondary collimators (bulky absorbers). The main tasks of this study are: to specify beam optics of the system, to calculate dependence of the scattering angle in the foil on the projectile species, to investigate importance of the inelastic nuclear interaction in the foil and to calculate dependence of the collimation efficiency on the projectile species. A concept for the collimation of partially-stripped ions is based on the stripping of remaining electrons and deflecting using a beam optical element towards a dump location. Residual activation and radiation damage issues of collimator materials are also being studied at GSI. Experimental results from irradiation of carbon-based materials by heavy ions are presented.
	Slides WEO3C02 [1.485 MB]

WEO3C06	Understanding Ion Induced Radiation Damage in Target Materials	target, heavy-ion, radiation, controls	476
	M. Tomut, C.L. Hubert GSI, Darmstadt, Germany M. Tomut INFIM, Bucharest, Romania
	Successful operation of next generations of radioactive beam facilities depends on the target survival in conditions of intense radiation field and thermo-mechanical solicitations induced by the driving ion beam. Material property degradation due to ion- beam induced damage will limit target lifetime, either by affecting target performance or, by reducing the material resilience. Similar problems are faced by beam protection elements at LHC. Understanding the mechanism of radiation damage induced by ion beam in these materials provides valuable knowledge for lifetime prediction and for the efforts to mitigate performance degradation. On their way through the target material, energetic heavy ions induce a trail of ionizations and excitations, resulting in formation of ion tracks consisting of complex defect structures. We give a review on the ion-induced damage creation in high power target materials, on the structural and thermo-mechanical property degradation and on their recovery in high temperature irradiation experiments.
	Slides WEO3C06 [4.439 MB]

THO1B04	Space Charge Effects in the NICA Collider Rings	collider, luminosity, emittance, electron	522
	O.S. Kozlov, S.A. Kostromin, I.N. Meshkov, A.O. Sidorin, A.V. Smirnov, G.V. Trubnikov JINR, Dubna, Moscow Region, Russia A.V. Eliseev JINR/VBLHEP, Dubna, Moscow region, Russia T. Katayama GSI, Darmstadt, Germany
	Accelerator complex NICA, developed at JINR, will provide an ion-ion (Au⁷⁹⁺) collisions at energies of 1-4.5 GeV/u, as well as experiments on collisions of polarized proton-proton and deuteron-deuteron beams. The calculations of the optical properties of superconducting collider rings have been aimed to create appropriate conditions for the collisions of beams and obtaining the required luminosity parameters in the working range of energies. The collider characteristics and the beam dynamics have been worked out mainly for ion-ion mode of the complex. The main effects limiting luminosity are the space charge dominating at the range of 1-3 GeV/u and the intrabeam scattering dominating for 3-4.5 GeV/u beams. Application of both electron and stochastic cooling methods is essential feature of the project. That allows us to suppress these effects in the corresponding energy ranges.
	Slides THO1B04 [3.938 MB]

THO3B02	SRF Technology Challenge and Development	cavity, linac, SRF, HOM	536
	A. Facco INFN/LNL, Legnaro (PD), Italy A. Facco FRIB, East Lansing, USA
	SRF technology in particle accelerators is in continuous evolution, providing a large variety of high gradient- low loss resonators with large apertures, suitable for many different beam current and energy regimes. Recent development was aiming not only at highest gradient and Q but also at improving field quality, reliability and cost reduction for large production. The SRF R&D effort, once concentrated mostly in the high energy electron machines, is increasingly focused to heavy ion linacs, energy recovery linacs and also to cavities for special applications. A concise overview of the present state of the art will be given.
	Slides THO3B02 [1.712 MB]

THO3B04	Beam Dynamics Studies of H⁻ Beam Chopping in a LEBT for Project X	emittance, solenoid, simulation, ion-source	546
	Q. Ji, D.P. Grote, A.R. Lambert, D. Li, T. Schenkel, J.W. Staples LBNL, Berkeley, California, USA
	Funding: This work is supported by the Office of Science, United States Department of Energy under DOE contract DE-AC02-05CH11231. Project X is proposed as a high intensity proton facility at Fermilab to support a world-leading program in neutrino and flavor physics over the next several decades. The front-end consists of an H⁻ ion source, low-energy beam transport (LEBT), and 162.5 MHz CW Radio-Frequency-Quadrupole (RFQ) accelerator. The LEBT design, currently under study at LBNL, would comprise two solenoids, a dipole magnet and a chopper. The LEBT chopper is designed to achieve 1 MHz beam chopping of a partially neutralized 30 keV, 5 mA H⁻ beam. Preliminary simulation studies show that chopping the beam before the second solenoid is more efficient in terms of chopper bias voltages. However, the space charge neutralization will be lost along the beam after the chopper and through the second solenoid. A beam dynamics study, using WARP 3D (a Particle-in-cell simulation code), has been carried out to investigate both the time-dependence of the partial neutralization in the segment after the chopper, as well as the beam stability and emittance growth. Benchmark experiments are ongoing and simulation and experimental results will be presented in this Workshop.
	Slides THO3B04 [1.868 MB]

THO3B05	Intense High Charge State Heavy Ion Beam Production for the Advanced Accelerators	electron, ion-source, ECRIS, plasma	550
	L.T. Sun IMP, Lanzhou, People's Republic of China
	Modern advanced heavy ion beam accelerators have strong needs for either dc or pulsed intense high charge state heavy ion beams, such as dc beams for FRIB project, SPIRAL2 project, HIRFL/IMP facility, RIBF/RIKEN facility ect, and pulsed beams for RHIC, LHC, FAIR project. After decades' development, only several typical ion sources have found their applications in these accelerators, i.e. ECR ion source, EBIS and LIS or Laser Ion Source. This paper will give a general review of the advantages and limitations of the three types of ion sources. The latest development and performance for the three types of ion sources will be presented.
	Slides THO3B05 [2.464 MB]

THO3C01	Optical Transition Radiation for Non-relativistic Ion Beams	target, photon, radiation, electron	580
	B. Walasek-Höhne, C.A. Andre, F. Becker, P. Forck, A. Reiter, M. Schwickert, R. Singh GSI, Darmstadt, Germany A.H. Lumpkin Fermilab, Batavia, USA
	In this contribution, recent results of Optical Transition Radiation (OTR) measurements with a non-relativistic heavy-ion beam will be presented. This feasibility study was prompted by previous measurements [1] and the theoretical estimation of expected signal strengths for the GSI linear accelerator UNILAC. For this experiment, an 11.4 MeV/u Uranium beam was chosen to investigate OTR signal from several target materials and to evaluate the working regime for the used experimental setup. The OTR light was either observed directly with an Image Intensified CCD camera (ICCD) or indirectly via a spectrometer for wavelength resolved data. A moveable stripping foil allowed measurements with two different ion charge states. The theoretical q2 dependency of the OTR process predicts a six-fold increase in light yield which was confirmed experimentally. Obtained OTR beam profiles were compered to SEM-Grid data. Moreover, ICCD gating feature, as well as the emitted light spectrum ruled out contribution of any background sources with longer emission time constant e.g. blackbody radiation. [1] C. Bal et al., "OTR from Non-relativistic Electrons", Proceedings of DIPAC03, PM04, Mainz Germany.
	Slides THO3C01 [1.905 MB]

THO3C03	Beam Induced Fluorescence - Profile Monitoring for Targets and Transport	vacuum, electron, target, cathode	586
	F. Becker, C.A. Andre, C. Dorn, P. Forck, R. Haseitl, B. Walasek-Höhne GSI, Darmstadt, Germany T. Dandl, T. Heindl, A. Ulrich TUM/Physik, Garching bei München, Germany J. Egberts, T. Papaevangelou CEA, Gif-sur-Yvette, France J. Marroncle CEA/IRFU, Gif-sur-Yvette, France
	Online profile diagnostic is preferred to monitor intense hadron beams at the Facility of Antiproton and Ion Research (FAIR). One instrument for beam profile measurement is the gas based Beam Induced Fluorescence (BIF)-monitor. It relies on the optical fluorescence of residual gas, excited by beam particles. In front of production targets for radioactive ion beams or in plasma physics applications, vacuum constraints are less restrictive and allow a sufficient number of fluorescence photons, even at minimum ionizing energies. Unwanted effects like radiation damage and radiation induced background need to be addressed as well. A profile comparison of BIF and Ionization Profile Monitor (IPM) in nitrogen and rare gases is presented. We studied the BIF method from 10^-3 to 30 mbar with an imaging spectrograph. Preferable fluorescence transitions and fundamental limitations are discussed.
	Slides THO3C03 [7.371 MB]

FRO1A01	Summary of Working Group A: Beam Dynamics in High-Intensity Circular Machines	simulation, space-charge, luminosity, resonance	606
	E. Métral CERN, Geneva, Switzerland G. Franchetti GSI, Darmstadt, Germany J.A. Holmes ORNL, Oak Ridge, Tennessee, USA
	In this proceeding we summarize the presentations of the HB2012 Workshop session on 'Beam Dynamics in High-Intensity Circular Machines' as well as the outcome of the discussion session. This working group hosted 29 presentations in dedicated sessions plus 5 presentations in a joint session with the working C.
	Slides FRO1A01 [7.420 MB]

FRO1A03	Accelerator System Design, Injection, Extraction and Beam-Material Interaction: Working Group C Summary Report	collimation, injection, proton, simulation	615
	N.V. Mokhov Fermilab, Batavia, USA D. Li LBNL, Berkeley, California, USA
	Working Group C summary:The performance of high beam power accelerators is strongly dependent on appropriate injection, acceleration and extraction system designs as well as on the way interactions of the beam with machine components are handled. The experience of the previous ICFA High-Brightness Beam workshops has proven that it is quite beneficial to combine analyses and discussion of these issues in one group, WG-C at this Workshop. A broad range of topics was presented and discussed in twenty talks at four WG-C sessions as well as at two joint WGA/C and WG-B/C sessions. Highlights from these talks, outstanding issues along with plans and proposals for future work are briefly described.
	Slides FRO1A03 [4.907 MB]

Paper

Title

Other Keywords

Page

MOI1B01

High Intensity Issues at FAIR

emittance, heavy-ion, synchrotron, ion-source

11

O.K. Kester
GSI, Darmstadt, Germany
O.K. Kester
IAP, Frankfurt am Main, Germany

Funding: Supported by the BMBF and Helmholtz International Center for FAIR
The facility for antiproton and ion research - FAIR - will produce secondary beams of unprecedented intensities [1]. In order to produce such intense secondary beams and to provide intense beams for the CBM [2] and APPA [3] collaboration, primary heavy ion beams of highest intensities will be required. The main driver accelerator of FAIR will be the SIS100 synchrotron. The GSI heavy ion accelerator facility will be the injector of ion beams for SIS100. In order to reach the final intensities above 10¹¹ ions per cycle, the injector chain has to be modified accordingly and the SIS100 has to be tailored to the needs. Therefore an intensity upgrade program of the GSI accelerator facility has been started, which comprises improvements of ion sources, of the injector linacs and of the heavy ion synchrotron SIS18. In addition, high energy beam transport and the SIS100 need to have a dedicated design, in order to handle beam losses. The issues of the upgrade programme and of the SIS100 design will be addressed.
[1] FAIR Green Paper- The Modularized Start Version, Oct.2009
[2] B.Friman et al.,The CBM physics Book, Series: Lecture Notes in Physics, Vol.814,2011
[3] http://www.fair-center.de/de/oeffentlichkeit/experimenteprogramm/appa-physics.html

Slides MOI1B01 [15.662 MB]

MOI1C03

Beam Loss Mechanisms in High Intensity Linacs

linac, DTL, proton, optics

36

M.A. Plum
ORNL, Oak Ridge, Tennessee, USA

Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725.
Beam loss is a critical issue in high intensity linacs, and much work is done during both the design and operation phases to keep the loss down to manageable levels. Linacs for H⁻ ion beams have many more loss mechanisms compared to H⁺ (proton) linacs. Interesting H⁻ beam loss mechanisms include residual gas stripping, H⁺ capture and acceleration, field stripping, and intra-beam stripping (IBSt). Beam halo formation, and ion source or RF turn on/off transients, are examples of beam loss mechanisms that are common for both H⁺ and H⁻ accelerators. The IBSt mechanism has recently been characterized at the Oak Ridge Spallation Neutron Source, and we have found that it accounts for most of the loss in the superconducting linac. In this paper we will detail the IBSt measurements, and also discuss the other beam loss mechanisms that are important for high intensity linacs.

Slides MOI1C03 [5.588 MB]

MOP205

Intense Heavy-Ion Bunches in Dual-harmonic RF Systems

impedance, factory, space-charge, synchrotron

51

M. Mehler, O. Chorniy
GSI, Darmstadt, Germany
O. Boine-Frankenheim
TEMF, TU Darmstadt, Darmstadt, Germany
O.K. Kester
IAP, Frankfurt am Main, Germany

For the synchrotron's SIS-18 and SIS-100 (FAIR) a dual-harmonic RF system with the harmonic numbers h1=2, h2=4 and h1=10, h2=20 respectively is planned. Such systems flatten the bunch form and increase the bunching factor Bf therefore reducing the transverse space charge force. For high currents cavity beam loading and potential-well distortion will deform the flattened bunch shape and lead to phase shifts. Optimized settings for the difference between the two RF phases and for the synchronous phase of the main RF harmonic are an option to reduce these effects. In this contribution we will analyse further aspects of the matched bunch distribution, possible instabilities of the obtained distribution will be discussed and results of machine experiments in SIS-18 will be presented.

MOP245

Quench Tests at the Large Hadron Collider with Collimation Losses at 3.5 Z TeV

proton, collimation, cryogenics, insertion

157

S. Redaelli, R.W. Aßmann, G. Bellodi, K. Brodzinski, R. Bruce, F. Burkart, M. Cauchi, D. Deboy, B. Dehning, E.B. Holzer, J.M. Jowett, E. Nebot Del Busto, M. Pojer, A. Priebe, A. Rossi, M. Sapinski, M. Schaumann, R. Schmidt, M. Solfaroli Camillocci, G. Valentino, R. Versteegen, J. Wenninger, D. Wollmann, M. Zerlauth
CERN, Geneva, Switzerland
L. Lari
IFIC, Valencia, Spain

The Large Hadron Collider (LHC) has been operating since 2010 at 3.5 TeV and 4.0 TeV without experiencing quenches induced by losses from circulating beams. This situation might change at 7 TeV where the reduced margins in the superconducting magnets. The critical locations are the dispersion suppressors (DSs) at either side of the cleaning and experimental insertions, where dispersive losses are maximum. It is therefore crucial to understand in detail the quench limits with beam loss distributions alike those occurring in standard operation. In order to address this aspect, quench tests were performed by inducing large beam losses on the primary collimators of the betatron cleaning insertion, for proton and lead ion beams of 3.5 Z TeV, to probe the quench limits of the DS magnets. Losses up to 500 kW were achieved without quenches. The measurement technique and the results obtained are presented, including observations of heat loads in the cryogenics system.

TUO1A04

Plasma Traps for Space-charge Studies: Status and Perspectives

plasma, resonance, laser, quadrupole

235

H. Okamoto, K. Fukushima, H. Higaki, K. Ito, K. Moriya, T. Okano, S. Yamaguchi
HU/AdSM, Higashi-Hiroshima, Japan
M. Endo
Hiroshima University, Higashi-Hiroshima, Japan
A. Mohri
Kyoto University, Graduate School of Human and Environmental Studies, Kyoto, Japan

Funding: Work supported in part by a Grant-in-Aid for Scientific Research, Japan Society for the Promotion of Science.
The beam physics group of Hiroshima University has developed non-neutral plasma traps dedicated solely to a wide range of beam dynamics studies. Those unique experimental tools approximately reproduce, in the laboratory frame, a many-body Coulomb system that is physically equivalent to a charged-particle beam observed in the center-of-mass frame. We have designed and constructed two different types of traps that employ either a radio-frequency electric quadrupole field or an axial magnetic field for transverse particle confinement. The former type is commonly referred to as "linear Paul trap" and the latter as "Penning trap". At present, three Paul traps and one Penning trap are operational while a new Penning trap for beam halo experiments is under construction. Each of these compact experimental facilities consists of a trap, many power supplies, a vacuum system, a computer control system, etc., and is called "S-POD (Simulator for Particle Orbit Dynamics)". S-POD is particularly useful for fundamental studies of high-intensity and high-brightness hadron beams. We here report on recent experimental outputs from S-POD and also briefly describe some future plans.

Slides TUO1A04 [7.790 MB]

TUO3A02

Status and Results of the UA9 Crystal Collimation Experiment at the CERN-SPS

collimation, proton, target, vacuum

245

S. Montesano, W. Scandale
CERN, Geneva, Switzerland

The UA9 experimental setup was installed in the CERN-SPS in 2009 to investigate the feasibility of the halo collimation assisted by bent crystals. Two-millimeter-long silicon crystals, with bending angles of about 150 microrad, are used as primary collimators instead than a standard amorphous target. Studies are performed with stored beams of protons and lead ions at 270 Z GeV. The loss profile is precisely measured in the area near to the crystal-collimator setup and in the downstream dispersion suppressor. A strong correlation of the losses in the two areas is observed and a steady reduction of dispersive losses is recorded at the onset of the channeling process. The loss map in the accelerator ring is is also reduced. These observations strongly support our expectation that the coherent deflection of the beam halo by a bent crystal should enhance the collimation efficiency in hadron colliders, such as LHC.
for the UA9 Collaboration

Slides TUO3A02 [5.936 MB]

TUO1B05

The Design and Commissioning of the Accelerator System of the Rare Isotope Reaccelerator - ReA3 at Michigan State University

cryomodule, rfq, target, linac

269

X. Wu, B. Arend, C. Compton, A. Facco, M.J. Johnson, D. Lawton, D. Leitner, F. Montes, S. Nash, J. Ottarson, G. Perdikakis, J. Popielarski, J.A. Rodriguez, M.J. Syphers, W. Wittmer, Q. Zhao
NSCL, East Lansing, Michigan, USA

Funding: This material is based upon work supported by the U.S. Department of Energy Office of Sciences under Cooperative Agreement DE-SC0000661
The National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University (MSU) is currently constructing its new rare isotope reaccelerator facility: ReA3, which will provide unique low-energy rare isotope beams by stopping fast rare isotopes in gas stopping systems, boosting the charge state in an Electron Beam Ion Trap (EBIT) and reaccelerating them in a superconducting linac. The rare isotope beams will be producted intially by Coupled Cyclotron Facility (CCF) at NSCL and later by Facility for Rare Isotope Beams (FRIB), currently being designed and constructed at MSU. The accelerator system consists of a Low Energy Beam Transport (LEBT), a room temperature RFQ and a linac utilizing superconducting QWRs. An achromatic High Energy Beam Transport (HEBT) will deliver the reaccelerated beams to the mutiple target stations. Beams from ReA3 will range from 3 MeV/u for heavy nuclei such as uranium to about 6 MeV/u for ions with A<50. The commissioning of the EBIT, RFQ and two cryomodules of the linac is currently underway. The ReA3 accelerator system design and status of commissioning will be presented.

Slides TUO1B05 [6.046 MB]

TUO1C05

Measurements and Interpretation of the Betatron Tune Spectra of High Intensity Bunched Beam at SIS-18

space-charge, synchrotron, acceleration, injection

310

R. Singh, O. Chorniy, P. Forck, R. Haseitl, W. Kaufmann, P. Kowina, K. Lang
GSI, Darmstadt, Germany
O. Boine-Frankenheim, R. Singh, T. Weiland
TEMF, TU Darmstadt, Darmstadt, Germany

The paper presents the status of the transverse tune measurements in the synchrotron SIS18 at GSI. Presently, there are two systems for tune measurements in operation in the SIS18, namely TOPOS (Tune, Orbit and POsition measurement System) and BBQ (Base Band tune measurement system). The first one is a digital system where the BPM signal is digitized and the bunch position is calculated numerically. The second system is an analog system, where the transverse bunch motion is detected using peak detector. Band limited noise and chirp excitations were used to excite the betatron oscillations. Measurements of the betatron tune spectra were done at injection energy at medium and high intensities. In the frequency spectra a number of peaks around the position of betatron tune were seen. The peaks can be attributed to different bunch head-tail modes which were observed in time domain. These modes were dependent on the beam intensity. In this paper we compare the tune spectra measured at high beam intensity with the theoretical model for the space charge affected head-tail modes.

Slides TUO1C05 [1.315 MB]

WEO1B02

Optics Design Optimization for IBS Dominated Beams

emittance, optics, scattering, damping

386

F. Antoniou, H. Bartosik, Y. Papaphilippou
CERN, Geneva, Switzerland
T. Demma
LAL, Orsay, France
N. Milas, A. Streun
PSI, Villigen PSI, Switzerland
M.T.F. Pivi
SLAC, Menlo Park, California, USA

Intra-beam scattering is a small angle multiple Coulomb scattering effect, leading to emittance growth. It becomes important for high brightness beams in low emittance lepton rings, but also hadron synchrotrons and ring colliders. Several theoretical models have been developed over the years, however, when the IBS becomes predominant, the divergence between the models becomes important. In addition, the theoretical models are based on the consideration of Gaussian beams and uncoupled transverse motion. Recently, two multi-particle tracking codes have been developed, in order to enable the understanding of the IBS influence on the beam distribution and the inclusion of coupling. The comparison between theoretical models in different lattices and different regimes is discussed here and the benchmarking of the theoretical models with the tracking codes is presented. Finally, first measurement results are presented in low emittance rings and hadron synchrotrons.

Slides WEO1B02 [2.389 MB]

WEO3B01

FRIB Accelerator Beam Dynamics Design and Challenges

linac, target, solenoid, rfq

404

Q. Zhao, A. Facco, F. Marti, E. Pozdeyev, M.J. Syphers, J. Wei, X. Wu, Y. Yamazaki, Y. Zhang
FRIB, East Lansing, Michigan, USA

Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661.
The Facility for Rare Isotope Beams (FRIB) will be a new national user facility for nuclear science. This cw, high power, superconducting (SC), heavy ion driver linac consists of a frontend to provide various highly charged ions at 0.5 MeV/u, three SC acceleration segments connected by two 180° bending systems to achieve an output beam energy of ≥200 MeV/u for all varieties of stable ions, and a beam delivery system to transport multi-charge-state beams to a fragmentation target at beam power of up to 400 kW. The linac utilizes four types of low-beta resonators with one frequency transition from 80.5 to 322 MHz after Segment 1, where ion charge state(s) is boosted through a stripper at ≤20 MeV/u. The beam dynamics design challenges include simultaneous acceleration of multi-charge-state beams to meet beam-on-target requirements, efficient acceleration of high intensity, low energy heavy ion beams, limitation of uncontrolled beam loss to <1 W/m, accommodation of multiple charge stripping scenarios, etc. We present the recent optimizations on linac lattice, the results of end-to-end beam simulations with machine errors, and the simulation of beam tuning and fault conditions.

Slides WEO3B01 [7.899 MB]

WEO3B02

Acceleration and Transportation of Multiple Ion Species at Ebis-based Preinjector

rfq, linac, booster, emittance

409

D. Raparia
BNL, Upton, Long Island, New York, USA

A new heavy ion pre-injector at Brookhaven National Laboratory consist of an electron Beam Ion Source (EBIS), RFQ and IH Linac and a short transport line. This pre-injector provide any ion Helium to Uranium at energy of 2 MeV/u for Relativistic Heavy Ion Collider (RHIC) and the NASA Space Radiation Laboratory (NSRL). EBIS produces multiple charge states of an ion of interested. These charge states are accelerated through RFQ (300 keV/u) and IH Linac (2 MeV/u) and transported to booster. Charge desecration occurs just before the injection into the booster. This paper discusses implication of acceleration and transports of multiple charge state ions.

Slides WEO3B02 [5.825 MB]

WEO3B03

PXIE at FNAL

rfq, cavity, kicker, diagnostics

414

N. Solyak, C.M. Baffes, A.Z. Chen, Y.I. Eidelman, B.M. Hanna, S.D. Holmes, V.A. Lebedev, S. Nagaitsev, J.-F. Ostiguy, R.J. Pasquinelli, D.W. Peterson, L.R. Prost, G.W. Saewert, A. Saini, V.E. Scarpine, A.V. Shemyakin, D. Sun, V.P. Yakovlev
Fermilab, Batavia, USA

PXIE is the integrated systems test for the Project X frontend. It is expected to accelerate 1-2 mA CW beam up to 30 MeV. The major goal of the project is a validation of the Project X concept and elimination of technical risks. It is expected to be constructed in the period of 2012-2016. In presentation the conceptual design of the experimental test facility, lattice and beam dynamics studies will be discussed in details.

Slides WEO3B03 [4.561 MB]

WEO3B04

RFQ Beam Dynamics Design for Large Science Facilities and Accelerator-Driven Systems

rfq, proton, bunching, linac

419

C. Zhang
IAP, Frankfurt am Main, Germany

Serving as the front-end of large science facilities and Accelerator-Driven Systems (ADS), the Radio-Frequency Quadrupole (RFQ) accelerator usually needs to reach low beam losses, good beam quality, high reliability, and cost savings such design goals at high beam intensities. To address the challenges for modern RFQs, a special beam dynamics design technique characterized by a reasonable and efficient bunching process with balanced space-charge forces has been developed as an alternative to the classic Four-Section Procedure proposed by Los Alamos National Laboratory (LANL). In this paper, the design studies of some recent RFQ projects will be presented as examples.

Slides WEO3B04 [3.698 MB]

WEO1C01

Effect of Self-consistency on Periodic Resonance Crossing

simulation, resonance, space-charge, synchrotron

429

G. Franchetti
GSI, Darmstadt, Germany

In high intensity bunched beams resonance crossing gives rise to emittance growth and beam loss. Both these effects build up after many synchrotron oscillations. Up to now long term modeling have relied on frozen models neglecting the physics of self-consistency. We address here this issue and present the state of the art of simulations also applied to the SIS100.

Slides WEO1C01 [3.657 MB]

WEO3C02

Collimation of Ion Beams

collimation, proton, scattering, heavy-ion

461

I. Strašík, O. Boine-Frankenheim
GSI, Darmstadt, Germany

The SIS 100 synchrotron as part of the FAIR project at GSI will accelerate various beam species from proton to uranium. An important issue is to minimize uncontrolled beam losses using a collimation system. An application of the two-stage collimation concept, well established for proton accelerators, is considered for the fully-stripped ion beams. The two-stage system consists of a primary collimator (a scattering foil) and secondary collimators (bulky absorbers). The main tasks of this study are:

to specify beam optics of the system,
to calculate dependence of the scattering angle in the foil on the projectile species,
to investigate importance of the inelastic nuclear interaction in the foil and
to calculate dependence of the collimation efficiency on the projectile species.

A concept for the collimation of partially-stripped ions is based on the stripping of remaining electrons and deflecting using a beam optical element towards a dump location. Residual activation and radiation damage issues of collimator materials are also being studied at GSI. Experimental results from irradiation of carbon-based materials by heavy ions are presented.

Slides WEO3C02 [1.485 MB]

WEO3C06

Understanding Ion Induced Radiation Damage in Target Materials

target, heavy-ion, radiation, controls

476

M. Tomut, C.L. Hubert
GSI, Darmstadt, Germany
M. Tomut
INFIM, Bucharest, Romania

Successful operation of next generations of radioactive beam facilities depends on the target survival in conditions of intense radiation field and thermo-mechanical solicitations induced by the driving ion beam. Material property degradation due to ion- beam induced damage will limit target lifetime, either by affecting target performance or, by reducing the material resilience. Similar problems are faced by beam protection elements at LHC. Understanding the mechanism of radiation damage induced by ion beam in these materials provides valuable knowledge for lifetime prediction and for the efforts to mitigate performance degradation. On their way through the target material, energetic heavy ions induce a trail of ionizations and excitations, resulting in formation of ion tracks consisting of complex defect structures. We give a review on the ion-induced damage creation in high power target materials, on the structural and thermo-mechanical property degradation and on their recovery in high temperature irradiation experiments.

Slides WEO3C06 [4.439 MB]

THO1B04

Space Charge Effects in the NICA Collider Rings

collider, luminosity, emittance, electron

522

O.S. Kozlov, S.A. Kostromin, I.N. Meshkov, A.O. Sidorin, A.V. Smirnov, G.V. Trubnikov
JINR, Dubna, Moscow Region, Russia
A.V. Eliseev
JINR/VBLHEP, Dubna, Moscow region, Russia
T. Katayama
GSI, Darmstadt, Germany

Accelerator complex NICA, developed at JINR, will provide an ion-ion (Au⁷⁹⁺) collisions at energies of 1-4.5 GeV/u, as well as experiments on collisions of polarized proton-proton and deuteron-deuteron beams. The calculations of the optical properties of superconducting collider rings have been aimed to create appropriate conditions for the collisions of beams and obtaining the required luminosity parameters in the working range of energies. The collider characteristics and the beam dynamics have been worked out mainly for ion-ion mode of the complex. The main effects limiting luminosity are the space charge dominating at the range of 1-3 GeV/u and the intrabeam scattering dominating for 3-4.5 GeV/u beams. Application of both electron and stochastic cooling methods is essential feature of the project. That allows us to suppress these effects in the corresponding energy ranges.

Slides THO1B04 [3.938 MB]

THO3B02

SRF Technology Challenge and Development

cavity, linac, SRF, HOM

536

A. Facco
INFN/LNL, Legnaro (PD), Italy
A. Facco
FRIB, East Lansing, USA

SRF technology in particle accelerators is in continuous evolution, providing a large variety of high gradient- low loss resonators with large apertures, suitable for many different beam current and energy regimes. Recent development was aiming not only at highest gradient and Q but also at improving field quality, reliability and cost reduction for large production. The SRF R&D effort, once concentrated mostly in the high energy electron machines, is increasingly focused to heavy ion linacs, energy recovery linacs and also to cavities for special applications. A concise overview of the present state of the art will be given.

Slides THO3B02 [1.712 MB]

THO3B04

Beam Dynamics Studies of H⁻ Beam Chopping in a LEBT for Project X

emittance, solenoid, simulation, ion-source

546

Q. Ji, D.P. Grote, A.R. Lambert, D. Li, T. Schenkel, J.W. Staples
LBNL, Berkeley, California, USA

Funding: This work is supported by the Office of Science, United States Department of Energy under DOE contract DE-AC02-05CH11231.
Project X is proposed as a high intensity proton facility at Fermilab to support a world-leading program in neutrino and flavor physics over the next several decades. The front-end consists of an H⁻ ion source, low-energy beam transport (LEBT), and 162.5 MHz CW Radio-Frequency-Quadrupole (RFQ) accelerator. The LEBT design, currently under study at LBNL, would comprise two solenoids, a dipole magnet and a chopper. The LEBT chopper is designed to achieve 1 MHz beam chopping of a partially neutralized 30 keV, 5 mA H⁻ beam. Preliminary simulation studies show that chopping the beam before the second solenoid is more efficient in terms of chopper bias voltages. However, the space charge neutralization will be lost along the beam after the chopper and through the second solenoid. A beam dynamics study, using WARP 3D (a Particle-in-cell simulation code), has been carried out to investigate both the time-dependence of the partial neutralization in the segment after the chopper, as well as the beam stability and emittance growth. Benchmark experiments are ongoing and simulation and experimental results will be presented in this Workshop.

Slides THO3B04 [1.868 MB]

THO3B05

Intense High Charge State Heavy Ion Beam Production for the Advanced Accelerators

electron, ion-source, ECRIS, plasma

550

L.T. Sun
IMP, Lanzhou, People's Republic of China

Modern advanced heavy ion beam accelerators have strong needs for either dc or pulsed intense high charge state heavy ion beams, such as dc beams for FRIB project, SPIRAL2 project, HIRFL/IMP facility, RIBF/RIKEN facility ect, and pulsed beams for RHIC, LHC, FAIR project. After decades' development, only several typical ion sources have found their applications in these accelerators, i.e. ECR ion source, EBIS and LIS or Laser Ion Source. This paper will give a general review of the advantages and limitations of the three types of ion sources. The latest development and performance for the three types of ion sources will be presented.

Slides THO3B05 [2.464 MB]

THO3C01

Optical Transition Radiation for Non-relativistic Ion Beams

target, photon, radiation, electron

580

B. Walasek-Höhne, C.A. Andre, F. Becker, P. Forck, A. Reiter, M. Schwickert, R. Singh
GSI, Darmstadt, Germany
A.H. Lumpkin
Fermilab, Batavia, USA

In this contribution, recent results of Optical Transition Radiation (OTR) measurements with a non-relativistic heavy-ion beam will be presented. This feasibility study was prompted by previous measurements [1] and the theoretical estimation of expected signal strengths for the GSI linear accelerator UNILAC. For this experiment, an 11.4 MeV/u Uranium beam was chosen to investigate OTR signal from several target materials and to evaluate the working regime for the used experimental setup. The OTR light was either observed directly with an Image Intensified CCD camera (ICCD) or indirectly via a spectrometer for wavelength resolved data. A moveable stripping foil allowed measurements with two different ion charge states. The theoretical q2 dependency of the OTR process predicts a six-fold increase in light yield which was confirmed experimentally. Obtained OTR beam profiles were compered to SEM-Grid data. Moreover, ICCD gating feature, as well as the emitted light spectrum ruled out contribution of any background sources with longer emission time constant e.g. blackbody radiation.
[1] C. Bal et al., "OTR from Non-relativistic Electrons", Proceedings of DIPAC03, PM04, Mainz Germany.

Slides THO3C01 [1.905 MB]

THO3C03

Beam Induced Fluorescence - Profile Monitoring for Targets and Transport

vacuum, electron, target, cathode

586

F. Becker, C.A. Andre, C. Dorn, P. Forck, R. Haseitl, B. Walasek-Höhne
GSI, Darmstadt, Germany
T. Dandl, T. Heindl, A. Ulrich
TUM/Physik, Garching bei München, Germany
J. Egberts, T. Papaevangelou
CEA, Gif-sur-Yvette, France
J. Marroncle
CEA/IRFU, Gif-sur-Yvette, France

Online profile diagnostic is preferred to monitor intense hadron beams at the Facility of Antiproton and Ion Research (FAIR). One instrument for beam profile measurement is the gas based Beam Induced Fluorescence (BIF)-monitor. It relies on the optical fluorescence of residual gas, excited by beam particles. In front of production targets for radioactive ion beams or in plasma physics applications, vacuum constraints are less restrictive and allow a sufficient number of fluorescence photons, even at minimum ionizing energies. Unwanted effects like radiation damage and radiation induced background need to be addressed as well. A profile comparison of BIF and Ionization Profile Monitor (IPM) in nitrogen and rare gases is presented. We studied the BIF method from 10^-3 to 30 mbar with an imaging spectrograph. Preferable fluorescence transitions and fundamental limitations are discussed.

Slides THO3C03 [7.371 MB]

FRO1A01

Summary of Working Group A: Beam Dynamics in High-Intensity Circular Machines

simulation, space-charge, luminosity, resonance

606

E. Métral
CERN, Geneva, Switzerland
G. Franchetti
GSI, Darmstadt, Germany
J.A. Holmes
ORNL, Oak Ridge, Tennessee, USA

In this proceeding we summarize the presentations of the HB2012 Workshop session on 'Beam Dynamics in High-Intensity Circular Machines' as well as the outcome of the discussion session. This working group hosted 29 presentations in dedicated sessions plus 5 presentations in a joint session with the working C.

Slides FRO1A01 [7.420 MB]

FRO1A03

Accelerator System Design, Injection, Extraction and Beam-Material Interaction: Working Group C Summary Report

collimation, injection, proton, simulation

615

N.V. Mokhov
Fermilab, Batavia, USA
D. Li
LBNL, Berkeley, California, USA

Working Group C summary:The performance of high beam power accelerators is strongly dependent on appropriate injection, acceleration and extraction system designs as well as on the way interactions of the beam with machine components are handled. The experience of the previous ICFA High-Brightness Beam workshops has proven that it is quite beneficial to combine analyses and discussion of these issues in one group, WG-C at this Workshop. A broad range of topics was presented and discussed in twenty talks at four WG-C sessions as well as at two joint WGA/C and WG-B/C sessions. Highlights from these talks, outstanding issues along with plans and proposals for future work are briefly described.

Slides FRO1A03 [4.907 MB]