IPAC2011 - List of Keywords (beam-transport)

Paper	Title	Other Keywords	Page
MOOCB03	A Novel Method for Quasi-non-interceptive Beam Profile Measurement in a Linac	linac, coupling, diagnostics, emittance	50
	A.V. Aleksandrov ORNL, Oak Ridge, Tennessee, USA
	Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. Beam profile diagnostics is an important tool for understanding beam dynamics in accelerators. Non-interceptive diagnostics have many great advantages but often are difficult in implementation. We suggest a method of measuring beam profiles that is not truly non-interceptive, because beam has to be intercepted at some point, preferably in the beginning of the linac. But significant difference from a conventional interceptive measurement is that beam is not intercepted at any of the points of measurement along the linac. One important application is measuring beam profiles within cryostats of a super-conducting linac. The equipment required for implementing this diagnostic is simple: a set of slits in the beginning of the accelerator, and a Beam Position Monitor (BPM) in the point of measurement. Beam profiles can be measured simultaneously at every BPM along the linac. In this paper we will discuss details of the method, its limitations, and effect of non-linearity, coupling and space charge. Results of a demonstration experiment at SNS will be presented and discussed.
	Slides MOOCB03 [3.365 MB]

MOPC017	Thermal Analyses of an RF Input Coupler for the IFMIF/EVEDA RFQ Linac	rfq, cavity, coupling, linac	101
	S. Maebara JAEA, Ibaraki-ken, Japan
	In the design of prototype RFQ linac for the IFMIF/EVEDA Project, a coupled cavity type of RFQ, which has a longitudinal length of 9.78m, was proposed to accelerate deuteron beam up to 5MeV. The operation frequency of 175MHz was selected to accelerate a large current of 125mA in CW mode. The driving RF power of 1.28 MW by 8 RF input couplers has to be injected to the RFQ cavity. As the RF input coupler design, RF losses including a loop antenna and an RF vacuum window, based on a 6 1/8 inch co-axial waveguide were calculated. In this conference, these results and thermal analysis results in CW operation mode will be presented in details.

MOPC047	RF Design of the Re-buncher Cavities for the LIPAC Deuteron Accelerator	cavity, impedance, vacuum, linac	184
	A. Lara, I. Podadera, F. Toral CIEMAT, Madrid, Spain
	Funding: Work partially supported by Spanish Ministry of Science and Innovation under project ENE2009-11230. Re-buncher cavities are an essential component of LIPAC (Linear IFMIF Prototype Accelerator), presently being built at Rokkasho (Japan). The deuteron beam exiting from the RFQ (Radio Frequency Quadrupole) structure has to be properly adapted to the superconducting RF (SRF) linac. Re-bunchers are placed in the Medium Energy Beam Transport (MEBT) line and their objective is to longitudinally focus the deuteron beam. IFMIF re-bunchers must provide a 350 kV E0LT at 175 MHz continuous wave (CW). The available length for the re-buncher is limited by the general layout of the MEBT. The high power dissipation derived from the high effective voltage and the short available length is an important design challenge. Four different normal conducting cavity designs were investigated: the pillbox type, double gap coaxial resonators, and multi-gap quarter wave and H resonators. The performance of these cavities was studied with the numerical codes HFSS and ANSYS. The fundamental frequency and field pattern of each re-buncher was investigated in HFSS. This work presents the results of such analyses.

MOPS025	Studies of Emittance Measurement by Quadrupole Variation for the IFMIF-EVEDA High Space Charge Beam	emittance, quadrupole, space-charge, simulation	652
	P.A.P. Nghiem, E. Counienc CEA/DSM/IRFU, France N. Chauvin CEA/IRFU, Gif-sur-Yvette, France C. Oliver CIEMAT, Madrid, Spain
	For the high-power (1 MW) beam of the IFMIF-EVEDA prototype accelerator, emittance measurements at nearly full power are only possible in a non-interceptive way. The method of quadrupole variation is explored here. Due to the high space charge regime, beam transport is strongly non-linear, and the classical matrix inversion is no more relevant. Inverse calculations using a multiparticle code is mandatory. In this paper, such emittance measurements are studied, aiming at checking its feasibility and evaluating its precision, taking into account the constraints of losses and quadrupole limitations.

MOPS043	Beam Performance in H⁻ Injector of LANSCE	emittance, simulation, space-charge, ion-source	697
	Y.K. Batygin, C. Pillai, L. Rybarcyk LANL, Los Alamos, New Mexico, USA
	During beam development time in 2010 we performed a series of beam emittance and beam profile scans along 750-keV H⁻ beam transport and 800-MeV linac. The purpose of the measurements was to determine the effects of space charge, slow-wave intensity modulation or chopping, RF buncher fields, and vacuum conditions on beam performance. As previously reported, from our observation and analysis we concluded that the 750 keV H⁻ beam transport is space-charge uncompensated. This presentation will look at the relative importance of space-charge, chopping, and RF-buncher on the observed emittance growth for beam in the short and long pulse regime as well as the effects of beam line vacuum degradation on beam size and emittance at the end of the linac. Y. Batygin et al., “Space-charge effects in H⁻ Low-Energy Beam Transport of LANSCE,” to be published in Proc. of the 2011 Particle Accelerator Conference, March 28-April 1, 2011, New York, NY.

MOPZ037	Extension of the 3-spectrometer Beam Transport Line for the KAOS Spectrometer at MAMI and Recent Status of MAMI	target, dipole, electron, status	880
	R.G. Heine, M. Dehn, K.-H. Kaiser, H.-J. Kreidel, U.L. Ludwig-Mertin IKP, Mainz, Germany
	Funding: Work supported by DFG (CRC443) and the German Federal State of Rhineland-Palatinate The institute for nuclear physics (KPH) at Mainz University is operating a 1.6 GeV c.w. microtron cascade (MAMI) for nuclear physics research. One of the vast experimental activities is electron scattering. A 3-spectrometer setup is used for cross-section measurements of hadron knock-out and meson production. The KAOS spectrometer magnet of GSI is installed there in parallel to detect particles from (e,e'K)reactions under small forward angles. So the primary electron beam has to transit the spectrometer and after this it has to hit the existing beam dump. Because of the existing experimental setup, this must be realised by deflecting the beam before the target that is rotated to be in line with the KAOS spectrometer's inlet. This paper will deal with the basic concept of a flexible beam transport line (BTL) magnet chicane for different KAOS forward angles, while keeping the forward beam direction for the 3-spectrometer setup untouched. A survey concept for assembly and adjustment of the BTL will be introduced, that is also useful for future adjustments of the target mount after target change. Results of the BTL commissioning and a general MAMI status will be presented as well.

TUPC055	Strongly Space Charge Dominated Beam Transport at 50 keV	solenoid, simulation, space-charge, electron	1123
	D. Heiliger, W. Hillert, B. Neff ELSA, Bonn, Germany
	Funding: supported by DFG (SFB/TR16) A pulsed (100 nC in 1 us), low energetic beam of polarized electrons is routinely provided by an inverted source of polarized electrons at ELSA. The beam transport to the linear accelerator is strongly space charge dominated due to the beam energy of 50 keV. Thus, the actual beam current has an impact on the beam dynamics, and the optics of the transfer line to the linear accelerator must be optimized with respect to the chosen beam intensity. Numerical simulations of the beam transport demonstrate that an intensity upgrade from 100 mA to 200 mA is feasible. In order to successfully adjust the focussing strength of the magnets according to the final results of the simulation, dedicated beam diagnostics like wire scanners suitable for extreme-high vacuum applications are required.

TUPC070	SAFARI, an Optimized Beam Stop Device for High Intensity Beams at the SPIRAL2 Facility	linac, neutron, beam-losses, vacuum	1162
	E. Schibler IN2P3 IPNL, Villeurbanne, France L. Perrot IPN, Orsay, France
	The SPIRAL2 facility at GANIL-Caen is now in its construction phase, with a project group including the participation of many French laboratories (CNRS, CEA) and international partners. The facility will be able to produce various accelerated beams at high intensities: 40 MeV Deuterons, 33 MeV Protons with intensity until 5mA and heavy ions with A/Q=3 up to 14.5MeV/u until 1mA current. We will present the final status of the 200kW beam stop located in the high energy beam transport lines. From the beam characteristics (HEBT line up to beam stop) and activation constraints, we studied and developed a complete design of a new high efficiency Beam Stop that has been nicknamed SAFARI (Système Arrêt Faisceau Adapté Rayons Intenses - Optimized Beam Stop Device for High Intensity Beams). Special focus will be done on the adequacy between beam dynamic and thermo-mechanical behavior. The Beam Stop shape marries to the beam characteristics in order to smooth for the best power density and improve thermo-mechanical behavior under nominal and critical beams. Optimization by various fluids studies and calculations led us to a new high efficiency counter-current water cooling system.

TUPC106	Courant-Snyder Invariant Density Screening Method for Emittance Analysis	emittance, hadron, background, ion-source	1263
	J.L. Sun, H.T. Jing, J. Tang IHEP Beijing, Beijing, People's Republic of China
	The emittance is an important characteristic of describing charged particle beams. In hadron accelerators, we often meet irregular beam distributions that are not appropriate to be described with a single rms or 95% or total emittance. In many cases beam halo should be described with very different Courant-Snyder parameters from the ones for beam core. A new method – Courant-Snyder invariant density screening method is developed for analyzing emittance data clearly and accurately. The method treats emittance data from both measurements and numerical simulations. The method uses the statistical distribution of the beam around each particle in phase space to mark its local density parameter, and then uses the density distribution to calculate the beam parameters such as Courant-Snyder parameters and emittance for different beam boundary definitions. The method has been used in the calculations for the beams from difference sources, and shows its advantages over other methods. An application code based on the method including the graphic interface has also been designed using the Matlab software.

TUPC130	Beam Test Performance of the Beam Position Monitors for the TBL Line of the CTF3 at CERN	pick-up, quadrupole, monitoring, linac	1326
	J.J. García-Garrigós, C. Blanch Gutierrez, J.V. Civera, A. Faus-Golfe IFIC, Valencia, Spain S. Döbert CERN, Geneva, Switzerland
	Funding: Funding Agency: FPA2010-21456-C02-01 A series of Inductive Pick-Ups (IPU) for Beam Position Monitoring (BPM) with its associated electronics were designed, constructed and tested at IFIC. A full set of 16 BPMs, so called BPS units, were successfully installed in the Test Beam Line (TBL) of the CLIC Test Facility (CTF3) at CERN. In this paper we present the results of the beam test carried out on the BPS units of the TBL in order to determine their beam performances and check the specified operational requirements. We focus particularly on the position resolution parameter which is the BPS figure of merit according to TBL demands and is expected to reach the 5um resolution at maximum beam current (28A). The beam test results of the BPS units are also compared with the parameters from their previous characterization test at lab.

WEPC043	Beam Transport in a Dielectric Wall Accelerator for Intensity Modulated Proton Therapy	proton, focusing, emittance, accelerating-gradient	2106
	Y.-J. Chen, D.T. Blackfield, S.D. Nelson, B. R. Poole LLNL, Livermore, California, USA
	Funding: This work performed under the auspices of the U. S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA2A27344. We are developing a compact dielectric wall accelerator (DWA) for intensity modulated proton therapy (IMPT) with a goal of fitting the compact proton DWA in a single room. To make the accelerator compact, the DWA needs to have a very high accelerating gradient. Also, beam transport in the DWA should be done with as few external lenses as possible. We have developed a transport scheme to transport the proton bunch in the DWA and to focus the charge bunch on the patient without using any external focusing lenses. The transport scheme would allow us change the proton beam spot size on the patient easily and rapidly. Results of simulations using 3-D, EM PIC code, LSP* will be presented. * G. J. Caporaso, Y-J Chen and S. E. Sampayan, Rev. of Accelerator Science and Technology, vol. 2, p. 253 (2009). ** Alliant Techsystems Inc., http://www.lspsuite.com/.

WEPC062	Second Order Achromats with Arbitrary Linear Transfer Matrices	quadrupole, sextupole, focusing, longitudinal-dynamics	2160
	V. Balandin, R. Brinkmann, W. Decking, N. Golubeva DESY, Hamburg, Germany
	The most obvious method to construct a second order achromat with an arbitrary (predefined) linear transfer matrix is to take a bend magnet system arranged in an achromat like fashion with the total transfer matrix equal to the identity matrix, attach a drift-quadrupole block with the desired linear transfer matrix and then adjust the sextupoles installed in the first part in such a way that the total system becomes a second order achromat. Unfortunately this is not always possible and, in general, the parts of such a system can not be designed independently. In this paper we give the necessary and sufficient conditions which must be satisfied for both parts of the system in order to become a second order achromat. In addition we provide some practical recommendations showing how these conditions can be fulfilled. We formulate these necessary and sufficient conditions using the group-theoretical point of view for the design of magnetic optical achromats as introduced in . V. Balandin, R. Brinkmann, W. Decking, N. Golubeva, "Two Cell Repetitive Achromats and Four Cell Mirror Symmetric Achromats", Proc. IPAC'10, Kyoto, Japan (2010).

WEPC063	Apochromatic Twiss Parameters of Drift-quadrupole Systems with Symmetries	quadrupole, betatron, lattice, chromatic-effects	2163
	V. Balandin, R. Brinkmann, W. Decking, N. Golubeva DESY, Hamburg, Germany
	It was shown in , that for every drift-quadrupole system there exists an unique set of Twiss parameters (apochromatic Twiss parameters), which will be transported through that system without first order chromatic distortions. In this paper we investigate apochromatic Twiss parameters of periodic, mirror symmetric and other drift-quadrupole systems with symmetries. V. Balandin, R. Brinkmann, W. Decking, N. Golubeva, "Apochromatic Beam Transport in Drift-Quadrupole Systems", Proc. IPAC'10, Kyoto, Japan (2010).

WEPC117	Symmetry Based Design for Beam Lines*	quadrupole, controls, target, insertion	2286
	S.N. Andrianov, A.N. Ivanov, M. Kosovtsov St. Petersburg State University, St. Petersburg, Russia
	Usually, the beam line design problems are solved using numerical optimization methods (for example, in the frame of so called global optimization paradigm). But this approach demonstrates enough effectiveness only after sufficient reduction of a control parameters set. In this paper we present the symmetry design concept based on symbolic computations for the corresponding beam line propagator. The combination of symbolic algebra codes (such as Maple, Mathematica, Maxima and so on) with the matrix formalism for Lie algebraic tools enables us to carry out the entire theoretical and computing processes for design of the beam line under study. For this purpose some of necessary physical requirements are formulated in the terms of the corresponding symmetry conditions. The suggested approach can be realized in both exact and approximate forms of the symmetry terms. The found conditions can sufficiently reduce the number of control parameters for the next optimization step.

WEPO014	Magnetic Design of Quadrupoles for the Medium and High Energy Beam Transport line of the LIPAC Accelerator	quadrupole, coupling, simulation, dipole	2424
	C. Oliver, B. Brañas, A. Ibarra, I. Podadera, F. Toral CIEMAT, Madrid, Spain
	Funding: Work partially supported by Spanish Ministry of Science and Innovation under project AIC10-A-000441 and ENE2009-11230. The LIPAC accelerator will be a 9 MeV, 125 mA cw deuteron accelerator which will verify the validity of the design of the future IFMIF accelerator. A Medium Energy Beam Transport line (MEBT) is necessary to handle the high current beam from the RFQ to the Superconducting RF accelerating cavities (SRF) whereas a High Energy Beam Transport line (HEBT) is used to match the beam from the SRF to the beam dump. The high space charge and beam power determine the beam dynamics in both transport lines. As a consequence, magnets with strong fields in a reduced space are required. Along the transport beamlines, there are different types of quadrupoles with steerers and a dipole. Special care is devoted to maximize the integrated fields in the available space. Both 2-D and 3-D magnetic calculations are used to optimize coil configurations. Magnetic performance and cost, both of magnet and power supply, have been taken into account for final choice. In this paper, the design of the resistive quadrupoles of the MEBT and HEBT of the LIPAC accelerator is presented.

WEPO021	Quadrupole Magnet with an Integrated Dipole Steering Element for the ISIS Beam Transport Line	dipole, quadrupole, target, proton	2445
	S.J.S. Jago, J. Shih, S.F.S. Tomlinson STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom S.M. Gurov BINP SB RAS, Novosibirsk, Russia
	A refurbishment of beam transport line to the original ISIS target station at the Rutherford Appleton Laboratory has recently been completed. This work involved a slight change to the optics in the area, which included the requirement for extra steering capabilities. Due to the space constraints in the region, a quadrupole magnet with an integrated dipole steering element was developed. The steering dipole consists of four saddle shaped coils situated within the bore of the quadrupole magnet providing a maximum steering angle of 2.5mrad. This paper outlines the magnetic and mechanical design of the steering element.

WEPS004	Confinement, Accumulation and Diagnostic of Low Energy Ion Beams in Toroidal Fields	ion, diagnostics, electron, injection	2487
	M. Droba, A. Ates, O. Meusel, H. Niebuhr, U. Ratzinger, J.F. Wagner IAP, Frankfurt am Main, Germany
	An optimized design of a stellarator-type storage ring for low energy ion beams was numerically investigated. The magnetic field variation along the circumference and therefore magnetic heating is suppressed by using simple circular correction coils. Particle-in-Cell (PIC) simulations in a magnetic flux coordinate system show the ability of high current ion beam accumulation in such a configuration with unique features for clockwise and anticlockwise moving beams. Additionally scaled down experiments with two 30 degree room temperature toroidal segments were performed to demonstrate toroidal transport and to develop optical beam diagnostics. Properties of multi-component beams, redistribution of transversal momenta in the non-adiabatic part of the experimental configuration and investigation of strongly confined beam induced electron clouds will be addressed.

WEPS068	Progress towards an RFQ-based Front End for LANSCE	rfq, linac, neutron, proton	2658
	R.W. Garnett, S.S. Kurennoy, J.F. O'Hara, L. Rybarcyk LANL, Los Alamos, New Mexico, USA A. Schempp IAP, Frankfurt am Main, Germany
	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 provides H⁻ and H⁺ beams to several user facilities that support Isotope Production, NNSA Stockpile Stewardship, and Basic Energy Science programs. These beams are initially accelerated to 750 keV using Cockcroft-Walton (CW) based injectors that have been in operation for over 37 years. They have failure modes which can result in prolonged operational downtime due to the unavailability of replacement parts. To reduce long-term operational risks and to realize future beam performance goals in support of the Materials Test Station (MTS) and the Matter-Radiation Interactions in Extremes (MaRIE) Facility, plans are underway to develop a Radio-Frequency Quadrupole (RFQ) based front end as a modern injector replacement for the existing CW injectors. Our progress to date will be discussed.

WEPS074	H⁻ Injection Studies of FFAG Accelerator at KURRI	injection, linac, proton, neutron	2676
	K. Okabe, Y. Niwa, I. Sakai University of Fukui, Faculty of Engineering, Fukui, Japan Y. Ishi, Y. Kuriyama, J.-B. Lagrange, Y. Mori, R. Nakano, B. Qin, T. Uesugi, E. Yamakawa KURRI, Osaka, Japan
	Aiming to demonstrate the basic feasibility of the accelerator driven sub-critical reactor (ADSR), proton Fixed Field Alternating Gradient (FFAG) accelerator complex as a neutron production driver has been constructed in Kyoto University Research Reactor Institute (KURRI). In order to upgrade beam power of the FFAG neutron source, a project about a new H⁻ linac injector for FFAG main ring instead of present injector has been started. A charge exchange multi-turn beam injection has been performed for the first time at FFAG main ring in KURRI. In this paper, the detail of injection system and beam study of low energy H⁻ injection at FFAG is described.

THPC030	Design of a BeamTransport Line from the SACLA Linac to the SPring-8 Storage Ring	lattice, emittance, linac, storage-ring	2975
	K. Tsumaki, K. Fukami, T. Watanabe JASRI/SPring-8, Hyogo-ken, Japan S. Itakura, N. Kumagai RIKEN/SPring-8, Hyogo, Japan
	The SPring-8 Angstrom Compact Free Electron Laser (SACLA) linac has high beam qualities. The normalized emittance is less than 1 mm.mrad and the bunch length is less than 100 fs. If this high quality beam is injected to the SPring-8 storage ring, many interesting experiments can be done. On the other hand, the upgrade of the SPring-8 storage ring is under contemplation. The dynamic aperture of the new storage ring is expected to be so small that the small emittance beam is required to keep high beam injection efficiency. The SACLA linac beam also fulfills this requirement. For these reasons, it was decided to connect the SACLA linac and the SPring-8 storage ring. Since there is already an injection transport line from the SPring-8 synchrotron to the storage ring, the new transport line from the linac to this transport line has been constructed. We designed the three types of magnet lattice for the new transport line; FODO, Double Bend Achromat and Triple Bend Achromat lattice. Emittance growth and bunch lengthening are calculated for each lattice and the beam qualities are compared. In this paper, lattice design and the comparison of the beam quality for each lattice are described. C. Mitsuda et al., this conference.

THPC144	The Construction Status of Beam Transport Line from XFEL-linac to SPring-8 Storage Ring	lattice, linac, alignment, storage-ring	3224
	C. Mitsuda, N. Azumi, T. Fujita, K. Fukami, H. Kimura, H. Ohkuma, M. Oishi, Y. Okayasu, M. Shoji, K. Tsumaki, T. Watanabe JASRI/SPring-8, Hyogo-ken, Japan M. Hasegawa, Y. Maeda, T. Nakanishi, Y. Tukamoto, M. Yamashita SES, Hyogo-pref., Japan N. Kumagai, S. Matsui RIKEN/SPring-8, Hyogo, Japan
	The beam transport line from XFEL-linac to SPring-8 storage ring is now under construction to use the ultra short bunched electron beam at the storage ring. The newly constructed line is about 300 m, which is just a half of the whole path from the XFEL linac to the storage ring. The beam extracted from XFEL-linac is guided to the beam transport tunnel connected to the matching section of booster synchrotron bending by 55.2 degrees horizontally and by 10.0 degrees vertically. A double-bend based lattice was adopted to reasonably suppress emittance growth and bunch lengthening. Supposing a bunch length and horizontal emittance at the exit of the XFEL-linac are estimated about 100 fs and 0.04 nmrad respectively, it is expected that the current beam emittance in storage ring is improved to about 0.4 nmrad and almost same bunch length including coherent synchrotron radiation effect. In 2010, the construction of extracting part from XFEL-linac was completed and we finished the installation and alignment of main components. The conceptual design and construction status of transport line will be presented with the emphasis on the detail magnet design and the fabrication.

THPS086	Compact Beam Delivery Systems for Ion Beam Therapy	ion, simulation, quadrupole, focusing	3633
	C. Sun, D. Arbelaez, S. Caspi, D. Robin, A. Sessler, W. Wan LBNL, Berkeley, California, USA M. Yoon POSTECH, Pohang, Kyungbuk, Republic of Korea
	Funding: Work supported by the United States Department of Energy under Contract No. DE-AC02-05CH11231 In this paper we present a coil winding concept for a large aperture, combined-function 90 degree magnet that allows for a significantly more compact carbon ion gantry. The winding concept enables the reduction in the size and weight of the magnet without compromising the important beam transport properties. Alternatively, a small aperture gantry requires a post-gantry scanner. We present a compact design for a post-gantry point-to-parallel scanning system.

Paper

Title

Other Keywords

Page

MOOCB03

A Novel Method for Quasi-non-interceptive Beam Profile Measurement in a Linac

linac, coupling, diagnostics, emittance

50

A.V. Aleksandrov
ORNL, Oak Ridge, Tennessee, USA

Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy.
Beam profile diagnostics is an important tool for understanding beam dynamics in accelerators. Non-interceptive diagnostics have many great advantages but often are difficult in implementation. We suggest a method of measuring beam profiles that is not truly non-interceptive, because beam has to be intercepted at some point, preferably in the beginning of the linac. But significant difference from a conventional interceptive measurement is that beam is not intercepted at any of the points of measurement along the linac. One important application is measuring beam profiles within cryostats of a super-conducting linac. The equipment required for implementing this diagnostic is simple: a set of slits in the beginning of the accelerator, and a Beam Position Monitor (BPM) in the point of measurement. Beam profiles can be measured simultaneously at every BPM along the linac. In this paper we will discuss details of the method, its limitations, and effect of non-linearity, coupling and space charge. Results of a demonstration experiment at SNS will be presented and discussed.

Slides MOOCB03 [3.365 MB]

MOPC017

Thermal Analyses of an RF Input Coupler for the IFMIF/EVEDA RFQ Linac

rfq, cavity, coupling, linac

101

S. Maebara
JAEA, Ibaraki-ken, Japan

In the design of prototype RFQ linac for the IFMIF/EVEDA Project, a coupled cavity type of RFQ, which has a longitudinal length of 9.78m, was proposed to accelerate deuteron beam up to 5MeV. The operation frequency of 175MHz was selected to accelerate a large current of 125mA in CW mode. The driving RF power of 1.28 MW by 8 RF input couplers has to be injected to the RFQ cavity. As the RF input coupler design, RF losses including a loop antenna and an RF vacuum window, based on a 6 1/8 inch co-axial waveguide were calculated. In this conference, these results and thermal analysis results in CW operation mode will be presented in details.

MOPC047

RF Design of the Re-buncher Cavities for the LIPAC Deuteron Accelerator

cavity, impedance, vacuum, linac

184

A. Lara, I. Podadera, F. Toral
CIEMAT, Madrid, Spain

Funding: Work partially supported by Spanish Ministry of Science and Innovation under project ENE2009-11230.
Re-buncher cavities are an essential component of LIPAC (Linear IFMIF Prototype Accelerator), presently being built at Rokkasho (Japan). The deuteron beam exiting from the RFQ (Radio Frequency Quadrupole) structure has to be properly adapted to the superconducting RF (SRF) linac. Re-bunchers are placed in the Medium Energy Beam Transport (MEBT) line and their objective is to longitudinally focus the deuteron beam. IFMIF re-bunchers must provide a 350 kV E0LT at 175 MHz continuous wave (CW). The available length for the re-buncher is limited by the general layout of the MEBT. The high power dissipation derived from the high effective voltage and the short available length is an important design challenge. Four different normal conducting cavity designs were investigated: the pillbox type, double gap coaxial resonators, and multi-gap quarter wave and H resonators. The performance of these cavities was studied with the numerical codes HFSS and ANSYS. The fundamental frequency and field pattern of each re-buncher was investigated in HFSS. This work presents the results of such analyses.

MOPS025

Studies of Emittance Measurement by Quadrupole Variation for the IFMIF-EVEDA High Space Charge Beam

emittance, quadrupole, space-charge, simulation

652

P.A.P. Nghiem, E. Counienc
CEA/DSM/IRFU, France
N. Chauvin
CEA/IRFU, Gif-sur-Yvette, France
C. Oliver
CIEMAT, Madrid, Spain

For the high-power (1 MW) beam of the IFMIF-EVEDA prototype accelerator, emittance measurements at nearly full power are only possible in a non-interceptive way. The method of quadrupole variation is explored here. Due to the high space charge regime, beam transport is strongly non-linear, and the classical matrix inversion is no more relevant. Inverse calculations using a multiparticle code is mandatory. In this paper, such emittance measurements are studied, aiming at checking its feasibility and evaluating its precision, taking into account the constraints of losses and quadrupole limitations.

MOPS043

Beam Performance in H⁻ Injector of LANSCE

emittance, simulation, space-charge, ion-source

697

Y.K. Batygin, C. Pillai, L. Rybarcyk
LANL, Los Alamos, New Mexico, USA

During beam development time in 2010 we performed a series of beam emittance and beam profile scans along 750-keV H⁻ beam transport and 800-MeV linac. The purpose of the measurements was to determine the effects of space charge, slow-wave intensity modulation or chopping, RF buncher fields, and vacuum conditions on beam performance. As previously reported*, from our observation and analysis we concluded that the 750 keV H⁻ beam transport is space-charge uncompensated. This presentation will look at the relative importance of space-charge, chopping, and RF-buncher on the observed emittance growth for beam in the short and long pulse regime as well as the effects of beam line vacuum degradation on beam size and emittance at the end of the linac.
* Y. Batygin et al., “Space-charge effects in H⁻ Low-Energy Beam Transport of LANSCE,” to be published in Proc. of the 2011 Particle Accelerator Conference, March 28-April 1, 2011, New York, NY.

MOPZ037

Extension of the 3-spectrometer Beam Transport Line for the KAOS Spectrometer at MAMI and Recent Status of MAMI

target, dipole, electron, status

880

R.G. Heine, M. Dehn, K.-H. Kaiser, H.-J. Kreidel, U.L. Ludwig-Mertin
IKP, Mainz, Germany

Funding: Work supported by DFG (CRC443) and the German Federal State of Rhineland-Palatinate
The institute for nuclear physics (KPH) at Mainz University is operating a 1.6 GeV c.w. microtron cascade (MAMI) for nuclear physics research. One of the vast experimental activities is electron scattering. A 3-spectrometer setup is used for cross-section measurements of hadron knock-out and meson production. The KAOS spectrometer magnet of GSI is installed there in parallel to detect particles from (e,e'K)reactions under small forward angles. So the primary electron beam has to transit the spectrometer and after this it has to hit the existing beam dump. Because of the existing experimental setup, this must be realised by deflecting the beam before the target that is rotated to be in line with the KAOS spectrometer's inlet. This paper will deal with the basic concept of a flexible beam transport line (BTL) magnet chicane for different KAOS forward angles, while keeping the forward beam direction for the 3-spectrometer setup untouched. A survey concept for assembly and adjustment of the BTL will be introduced, that is also useful for future adjustments of the target mount after target change. Results of the BTL commissioning and a general MAMI status will be presented as well.

TUPC055

Strongly Space Charge Dominated Beam Transport at 50 keV

solenoid, simulation, space-charge, electron

1123

D. Heiliger, W. Hillert, B. Neff
ELSA, Bonn, Germany

Funding: supported by DFG (SFB/TR16)
A pulsed (100 nC in 1 us), low energetic beam of polarized electrons is routinely provided by an inverted source of polarized electrons at ELSA. The beam transport to the linear accelerator is strongly space charge dominated due to the beam energy of 50 keV. Thus, the actual beam current has an impact on the beam dynamics, and the optics of the transfer line to the linear accelerator must be optimized with respect to the chosen beam intensity. Numerical simulations of the beam transport demonstrate that an intensity upgrade from 100 mA to 200 mA is feasible. In order to successfully adjust the focussing strength of the magnets according to the final results of the simulation, dedicated beam diagnostics like wire scanners suitable for extreme-high vacuum applications are required.

TUPC070

SAFARI, an Optimized Beam Stop Device for High Intensity Beams at the SPIRAL2 Facility

linac, neutron, beam-losses, vacuum

1162

E. Schibler
IN2P3 IPNL, Villeurbanne, France
L. Perrot
IPN, Orsay, France

The SPIRAL2 facility at GANIL-Caen is now in its construction phase, with a project group including the participation of many French laboratories (CNRS, CEA) and international partners. The facility will be able to produce various accelerated beams at high intensities: 40 MeV Deuterons, 33 MeV Protons with intensity until 5mA and heavy ions with A/Q=3 up to 14.5MeV/u until 1mA current. We will present the final status of the 200kW beam stop located in the high energy beam transport lines. From the beam characteristics (HEBT line up to beam stop) and activation constraints, we studied and developed a complete design of a new high efficiency Beam Stop that has been nicknamed SAFARI (Système Arrêt Faisceau Adapté Rayons Intenses - Optimized Beam Stop Device for High Intensity Beams). Special focus will be done on the adequacy between beam dynamic and thermo-mechanical behavior. The Beam Stop shape marries to the beam characteristics in order to smooth for the best power density and improve thermo-mechanical behavior under nominal and critical beams. Optimization by various fluids studies and calculations led us to a new high efficiency counter-current water cooling system.

TUPC106

Courant-Snyder Invariant Density Screening Method for Emittance Analysis

emittance, hadron, background, ion-source

1263

J.L. Sun, H.T. Jing, J. Tang
IHEP Beijing, Beijing, People's Republic of China

The emittance is an important characteristic of describing charged particle beams. In hadron accelerators, we often meet irregular beam distributions that are not appropriate to be described with a single rms or 95% or total emittance. In many cases beam halo should be described with very different Courant-Snyder parameters from the ones for beam core. A new method – Courant-Snyder invariant density screening method is developed for analyzing emittance data clearly and accurately. The method treats emittance data from both measurements and numerical simulations. The method uses the statistical distribution of the beam around each particle in phase space to mark its local density parameter, and then uses the density distribution to calculate the beam parameters such as Courant-Snyder parameters and emittance for different beam boundary definitions. The method has been used in the calculations for the beams from difference sources, and shows its advantages over other methods. An application code based on the method including the graphic interface has also been designed using the Matlab software.

TUPC130

Beam Test Performance of the Beam Position Monitors for the TBL Line of the CTF3 at CERN

pick-up, quadrupole, monitoring, linac

1326

J.J. García-Garrigós, C. Blanch Gutierrez, J.V. Civera, A. Faus-Golfe
IFIC, Valencia, Spain
S. Döbert
CERN, Geneva, Switzerland

Funding: Funding Agency: FPA2010-21456-C02-01
A series of Inductive Pick-Ups (IPU) for Beam Position Monitoring (BPM) with its associated electronics were designed, constructed and tested at IFIC. A full set of 16 BPMs, so called BPS units, were successfully installed in the Test Beam Line (TBL) of the CLIC Test Facility (CTF3) at CERN. In this paper we present the results of the beam test carried out on the BPS units of the TBL in order to determine their beam performances and check the specified operational requirements. We focus particularly on the position resolution parameter which is the BPS figure of merit according to TBL demands and is expected to reach the 5um resolution at maximum beam current (28A). The beam test results of the BPS units are also compared with the parameters from their previous characterization test at lab.

WEPC043

Beam Transport in a Dielectric Wall Accelerator for Intensity Modulated Proton Therapy

proton, focusing, emittance, accelerating-gradient

2106

Y.-J. Chen, D.T. Blackfield, S.D. Nelson, B. R. Poole
LLNL, Livermore, California, USA

Funding: This work performed under the auspices of the U. S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA2A27344.
We are developing a compact dielectric wall accelerator (DWA) for intensity modulated proton therapy (IMPT) with a goal of fitting the compact proton DWA in a single room*. To make the accelerator compact, the DWA needs to have a very high accelerating gradient. Also, beam transport in the DWA should be done with as few external lenses as possible. We have developed a transport scheme to transport the proton bunch in the DWA and to focus the charge bunch on the patient without using any external focusing lenses. The transport scheme would allow us change the proton beam spot size on the patient easily and rapidly. Results of simulations using 3-D, EM PIC code, LSP** will be presented.
* G. J. Caporaso, Y-J Chen and S. E. Sampayan, Rev. of Accelerator Science and Technology, vol. 2, p. 253 (2009).
** Alliant Techsystems Inc., http://www.lspsuite.com/.

WEPC062

Second Order Achromats with Arbitrary Linear Transfer Matrices

quadrupole, sextupole, focusing, longitudinal-dynamics

2160

V. Balandin, R. Brinkmann, W. Decking, N. Golubeva
DESY, Hamburg, Germany

The most obvious method to construct a second order achromat with an arbitrary (predefined) linear transfer matrix is to take a bend magnet system arranged in an achromat like fashion with the total transfer matrix equal to the identity matrix, attach a drift-quadrupole block with the desired linear transfer matrix and then adjust the sextupoles installed in the first part in such a way that the total system becomes a second order achromat. Unfortunately this is not always possible and, in general, the parts of such a system can not be designed independently. In this paper we give the necessary and sufficient conditions which must be satisfied for both parts of the system in order to become a second order achromat. In addition we provide some practical recommendations showing how these conditions can be fulfilled. We formulate these necessary and sufficient conditions using the group-theoretical point of view for the design of magnetic optical achromats as introduced in *.
* V. Balandin, R. Brinkmann, W. Decking, N. Golubeva, "Two Cell Repetitive Achromats and Four Cell Mirror Symmetric Achromats", Proc. IPAC'10, Kyoto, Japan (2010).

WEPC063

Apochromatic Twiss Parameters of Drift-quadrupole Systems with Symmetries

quadrupole, betatron, lattice, chromatic-effects

2163

V. Balandin, R. Brinkmann, W. Decking, N. Golubeva
DESY, Hamburg, Germany

It was shown in *, that for every drift-quadrupole system there exists an unique set of Twiss parameters (apochromatic Twiss parameters), which will be transported through that system without first order chromatic distortions. In this paper we investigate apochromatic Twiss parameters of periodic, mirror symmetric and other drift-quadrupole systems with symmetries.
* V. Balandin, R. Brinkmann, W. Decking, N. Golubeva, "Apochromatic Beam Transport in Drift-Quadrupole Systems", Proc. IPAC'10, Kyoto, Japan (2010).

WEPC117

Symmetry Based Design for Beam Lines*

quadrupole, controls, target, insertion

2286

S.N. Andrianov, A.N. Ivanov, M. Kosovtsov
St. Petersburg State University, St. Petersburg, Russia

Usually, the beam line design problems are solved using numerical optimization methods (for example, in the frame of so called global optimization paradigm). But this approach demonstrates enough effectiveness only after sufficient reduction of a control parameters set. In this paper we present the symmetry design concept based on symbolic computations for the corresponding beam line propagator. The combination of symbolic algebra codes (such as Maple, Mathematica, Maxima and so on) with the matrix formalism for Lie algebraic tools enables us to carry out the entire theoretical and computing processes for design of the beam line under study. For this purpose some of necessary physical requirements are formulated in the terms of the corresponding symmetry conditions. The suggested approach can be realized in both exact and approximate forms of the symmetry terms. The found conditions can sufficiently reduce the number of control parameters for the next optimization step.

WEPO014

Magnetic Design of Quadrupoles for the Medium and High Energy Beam Transport line of the LIPAC Accelerator

quadrupole, coupling, simulation, dipole

2424

C. Oliver, B. Brañas, A. Ibarra, I. Podadera, F. Toral
CIEMAT, Madrid, Spain

Funding: Work partially supported by Spanish Ministry of Science and Innovation under project AIC10-A-000441 and ENE2009-11230.
The LIPAC accelerator will be a 9 MeV, 125 mA cw deuteron accelerator which will verify the validity of the design of the future IFMIF accelerator. A Medium Energy Beam Transport line (MEBT) is necessary to handle the high current beam from the RFQ to the Superconducting RF accelerating cavities (SRF) whereas a High Energy Beam Transport line (HEBT) is used to match the beam from the SRF to the beam dump. The high space charge and beam power determine the beam dynamics in both transport lines. As a consequence, magnets with strong fields in a reduced space are required. Along the transport beamlines, there are different types of quadrupoles with steerers and a dipole. Special care is devoted to maximize the integrated fields in the available space. Both 2-D and 3-D magnetic calculations are used to optimize coil configurations. Magnetic performance and cost, both of magnet and power supply, have been taken into account for final choice. In this paper, the design of the resistive quadrupoles of the MEBT and HEBT of the LIPAC accelerator is presented.

WEPO021

Quadrupole Magnet with an Integrated Dipole Steering Element for the ISIS Beam Transport Line

dipole, quadrupole, target, proton

2445

S.J.S. Jago, J. Shih, S.F.S. Tomlinson
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
S.M. Gurov
BINP SB RAS, Novosibirsk, Russia

A refurbishment of beam transport line to the original ISIS target station at the Rutherford Appleton Laboratory has recently been completed. This work involved a slight change to the optics in the area, which included the requirement for extra steering capabilities. Due to the space constraints in the region, a quadrupole magnet with an integrated dipole steering element was developed. The steering dipole consists of four saddle shaped coils situated within the bore of the quadrupole magnet providing a maximum steering angle of 2.5mrad. This paper outlines the magnetic and mechanical design of the steering element.

WEPS004

Confinement, Accumulation and Diagnostic of Low Energy Ion Beams in Toroidal Fields

ion, diagnostics, electron, injection

2487

M. Droba, A. Ates, O. Meusel, H. Niebuhr, U. Ratzinger, J.F. Wagner
IAP, Frankfurt am Main, Germany

An optimized design of a stellarator-type storage ring for low energy ion beams was numerically investigated. The magnetic field variation along the circumference and therefore magnetic heating is suppressed by using simple circular correction coils. Particle-in-Cell (PIC) simulations in a magnetic flux coordinate system show the ability of high current ion beam accumulation in such a configuration with unique features for clockwise and anticlockwise moving beams. Additionally scaled down experiments with two 30 degree room temperature toroidal segments were performed to demonstrate toroidal transport and to develop optical beam diagnostics. Properties of multi-component beams, redistribution of transversal momenta in the non-adiabatic part of the experimental configuration and investigation of strongly confined beam induced electron clouds will be addressed.

WEPS068

Progress towards an RFQ-based Front End for LANSCE

rfq, linac, neutron, proton

2658

R.W. Garnett, S.S. Kurennoy, J.F. O'Hara, L. Rybarcyk
LANL, Los Alamos, New Mexico, USA
A. Schempp
IAP, Frankfurt am Main, Germany

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 provides H⁻ and H⁺ beams to several user facilities that support Isotope Production, NNSA Stockpile Stewardship, and Basic Energy Science programs. These beams are initially accelerated to 750 keV using Cockcroft-Walton (CW) based injectors that have been in operation for over 37 years. They have failure modes which can result in prolonged operational downtime due to the unavailability of replacement parts. To reduce long-term operational risks and to realize future beam performance goals in support of the Materials Test Station (MTS) and the Matter-Radiation Interactions in Extremes (MaRIE) Facility, plans are underway to develop a Radio-Frequency Quadrupole (RFQ) based front end as a modern injector replacement for the existing CW injectors. Our progress to date will be discussed.

WEPS074

H⁻ Injection Studies of FFAG Accelerator at KURRI

injection, linac, proton, neutron

2676

K. Okabe, Y. Niwa, I. Sakai
University of Fukui, Faculty of Engineering, Fukui, Japan
Y. Ishi, Y. Kuriyama, J.-B. Lagrange, Y. Mori, R. Nakano, B. Qin, T. Uesugi, E. Yamakawa
KURRI, Osaka, Japan

Aiming to demonstrate the basic feasibility of the accelerator driven sub-critical reactor (ADSR), proton Fixed Field Alternating Gradient (FFAG) accelerator complex as a neutron production driver has been constructed in Kyoto University Research Reactor Institute (KURRI). In order to upgrade beam power of the FFAG neutron source, a project about a new H⁻ linac injector for FFAG main ring instead of present injector has been started. A charge exchange multi-turn beam injection has been performed for the first time at FFAG main ring in KURRI. In this paper, the detail of injection system and beam study of low energy H⁻ injection at FFAG is described.

THPC030

Design of a BeamTransport Line from the SACLA Linac to the SPring-8 Storage Ring

lattice, emittance, linac, storage-ring

2975

K. Tsumaki, K. Fukami, T. Watanabe
JASRI/SPring-8, Hyogo-ken, Japan
S. Itakura, N. Kumagai
RIKEN/SPring-8, Hyogo, Japan

The SPring-8 Angstrom Compact Free Electron Laser (SACLA) linac has high beam qualities. The normalized emittance is less than 1 mm.mrad and the bunch length is less than 100 fs. If this high quality beam is injected to the SPring-8 storage ring, many interesting experiments can be done. On the other hand, the upgrade of the SPring-8 storage ring is under contemplation. The dynamic aperture of the new storage ring is expected to be so small that the small emittance beam is required to keep high beam injection efficiency. The SACLA linac beam also fulfills this requirement. For these reasons, it was decided to connect the SACLA linac and the SPring-8 storage ring. Since there is already an injection transport line from the SPring-8 synchrotron to the storage ring, the new transport line from the linac to this transport line has been constructed*. We designed the three types of magnet lattice for the new transport line; FODO, Double Bend Achromat and Triple Bend Achromat lattice. Emittance growth and bunch lengthening are calculated for each lattice and the beam qualities are compared. In this paper, lattice design and the comparison of the beam quality for each lattice are described.
* C. Mitsuda et al., this conference.

THPC144

The Construction Status of Beam Transport Line from XFEL-linac to SPring-8 Storage Ring

lattice, linac, alignment, storage-ring

3224

C. Mitsuda, N. Azumi, T. Fujita, K. Fukami, H. Kimura, H. Ohkuma, M. Oishi, Y. Okayasu, M. Shoji, K. Tsumaki, T. Watanabe
JASRI/SPring-8, Hyogo-ken, Japan
M. Hasegawa, Y. Maeda, T. Nakanishi, Y. Tukamoto, M. Yamashita
SES, Hyogo-pref., Japan
N. Kumagai, S. Matsui
RIKEN/SPring-8, Hyogo, Japan

The beam transport line from XFEL-linac to SPring-8 storage ring is now under construction to use the ultra short bunched electron beam at the storage ring. The newly constructed line is about 300 m, which is just a half of the whole path from the XFEL linac to the storage ring. The beam extracted from XFEL-linac is guided to the beam transport tunnel connected to the matching section of booster synchrotron bending by 55.2 degrees horizontally and by 10.0 degrees vertically. A double-bend based lattice was adopted to reasonably suppress emittance growth and bunch lengthening. Supposing a bunch length and horizontal emittance at the exit of the XFEL-linac are estimated about 100 fs and 0.04 nmrad respectively, it is expected that the current beam emittance in storage ring is improved to about 0.4 nmrad and almost same bunch length including coherent synchrotron radiation effect. In 2010, the construction of extracting part from XFEL-linac was completed and we finished the installation and alignment of main components. The conceptual design and construction status of transport line will be presented with the emphasis on the detail magnet design and the fabrication.

THPS086

Compact Beam Delivery Systems for Ion Beam Therapy

ion, simulation, quadrupole, focusing

3633

C. Sun, D. Arbelaez, S. Caspi, D. Robin, A. Sessler, W. Wan
LBNL, Berkeley, California, USA
M. Yoon
POSTECH, Pohang, Kyungbuk, Republic of Korea

Funding: Work supported by the United States Department of Energy under Contract No. DE-AC02-05CH11231
In this paper we present a coil winding concept for a large aperture, combined-function 90 degree magnet that allows for a significantly more compact carbon ion gantry. The winding concept enables the reduction in the size and weight of the magnet without compromising the important beam transport properties. Alternatively, a small aperture gantry requires a post-gantry scanner. We present a compact design for a post-gantry point-to-parallel scanning system.