IPAC2014 - Classification: 04 Hadron Accelerators / T12 Beam Injection/Extraction and Transport

Paper	Title	Page
MOPME076	Upgrade of the SPS Injection Kicker System for LHC High Luminosity Operation with Heavy Ion Beam	547
	T. Kramer, J. Borburgh, L. Ducimetière, B. Goddard, L. Sermeus, J.A. Uythoven, F.M. Velotti CERN, Geneva, Switzerland
	In the context of the LHC High Luminosity Upgrade project a performance upgrade for heavy ions is envisaged. One of the performance limitations is the rise time of the present SPS injection kicker system MKP. A reduction of the rise time for lead ions was studied in line with a modification of the whole injection system. This paper briefly describes the different rise time options studied for an initially proposed dedicated ion kicker system MKP-I, focuses however on a cost effective alternative using the presently installed 12 MKPS magnets connected to a new fast pulse forming line. As only 12 out of the 16 injection kicker magnets would be fast enough to be used in an upgraded system, additional deflection has to be provided by the septa. The beam optics for that variant is highlighted and first requirements for the septum elements are stipulated. The paper concludes with a failure analysis of the proposed scheme.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPME076
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MOPRI087	Challenges of the Technical Layout of the SIS 100 Extraction System	815
	N. Pyka, L.H.J. Bozyk, U. Kopf, C. Mühle, D. Ondreka, P. Rottländer, P.J. Spiller, St. Wilfert GSI, Darmstadt, Germany A.G. Kalimov St. Petersburg State Polytechnic University, St. Petersburg, Russia
	The FAIR synchrotron SIS100 which is under construction will provide heavy ion and proton beams of high intensity with fast and slow extraction. All extraction devices, including an internal emergency beam dump system, are installed within one straight section. This way, expected systematic beam loss is kept in a relatively small area of the synchrotron. In this area, it is rather challenging to protect components against high radiation fields, to keep XHV conditions, and to allow for maintenance of highly activated components to assure reliable beam operation. In this contribution, the technical measures to fulfill the requirements for the extraction straight section of SIS100 will be presented. These include remote controlled devices to move apart magnet yokes for the purpose of placing beam pipe heater; dedicated star-shaped vacuum chambers with integrated collimators and NEG-panels to reduce pressure bumps due to lost particles behind the electrostatic septa; a high-power multi-stage vertical extraction septum including a variable horizontal deflection.
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MOPRI088	Beam Transport Experiments Using Gabor Lenses	818
	K. Schulte, M. Droba, S. Klaproth, O. Meusel, D. Noll, U. Ratzinger IAP, Frankfurt am Main, Germany
	A prototype Gabor lens has successfully been tested at the GSI High Current Test Injector (HOSTI). The experiments comprised the investigation of an emittance dominated and a space-charge dominated beam transport. In particular, the high-current measurements represent a necessary step towards evaluating the focusing performance of the lens and to gain experience in a real accelerator environment. Besides the evaluation of the technical feasibility, the behavior of the electron cloud was characterized by the parameter analysis of the confined non-neutral plasma during beam transport measurements as well as subsequently performed diagnostic experiments. This contribution will present experimental results as well as numerical studies on an improved Gabor lens design for the possible application at the GSI High Current Injector (HSI) in the context of an upgrade program for FAIR. K. Schulte et al., Proc. of IPAC'13, Shanghai, China, 2013, THPWO021 **L. Dahl, Proc. of HIAT’09, Venice, Italy, 2009, FR-01
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MOPRI089	Upgrade of J-PARC Fast Extraction System	821
	K. Fan, K. Ishii, H. Matsumoto, N. Matsumoto, T. Sugimoto KEK, Ibaraki, Japan T. Shibata JAEA, Ibaraki-ken, Japan
	The J-PARC main ring (MR) fast extraction (FX) system has two functions: to deliver a high power beam to the neutrino experimental facility and to dump the beam at any time in case of hardware failures. The present FX system consists of five bipolar kickers and eight bipolar septa. In order to raise the beam power to the design limit, both the beam intensity and the repetition rate will increase gradually. The FX system needs to be upgraded to satisfy the new requirements. The upgrade includes FX orbit optimization and new design of devices. Firstly, two high performance eddy current septa have been designed and fabricated. Then downstream high field septa are redesigned and using ceramic beam pipe to eliminate eddy current effects, which meets the requirement of high repetition rate operation. A new large physical aperture quadrupole is needed to accommodate high intensity beam. In order to evaluate the beam loss in the new system, realistic 3D beam tracking is studied.
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MOPRI090	Beam Distribution Transformation with SFMs at 3MeV C-ADS Beamline	824
	H. Geng, P. Cheng, C. Meng, S. Pei, B. Sun, H.J. Wang, B. Xu, F. Yan, Y.L. Zhao IHEP, Beijing, People's Republic of China
	The C-ADS project is building a test facility at the Institute of High Energy Physics. The design goal of the test facility is 10MeV beam energy with a continuous beam current of 10mA. To sustain the 100kW CW beam power at the beam dump, a beam distribution transform system is designed. The Step Field Magnets (SFMs) are used to transform the beam distribution from Gaussian to uniform. In this test stand, two sets of SFMs will be employed to manipulate the beam distribution. At the first commissioning stage, the bump dump line will be connected to the Medium Energy Beam Transport-1 (MEBT1) to test the beam manipulation scheme. The design and error analysis of this 3MeV beam dump line will be discussed in this paper.
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MOPRI091	Resonant Slow Extraction in Synchrotrons by Using Anti-symmetric Sextupole Fields	827
SUSPSNE044	use link to see paper's listing under its alternate paper code
	Y. Zou, J.Y. Tang IHEP, Beijing, People's Republic of China
	This paper proposes a novel method for non-resonant slow extraction by using special anti-symmetric sextupole field in synchrotrons. The method has the potential in applications asking for stable slow extraction and in the halo collimation of very large machine such as LHC. Our studies show that the slow extraction by using anti-symmetric sextupole field has some advantages compared to the normal sextupole field which is the normal extraction method. One of them is that it can work at almost arbitrary tune, so that it can avoid the problem of the intensity variation caused by the ripples of magnet supplies. Studies by Hamiltonian theory and simulations which meet well show that the stable region only depends on the anti-symmetric sextupole field strength and the particles outside will be driven out in two directions which are similar to the second-order resonant extraction but with spiral steps as in the third-order resonance extraction. The beam can be extracted with a very stable intensity by gradually increasing the field strength. The multi-particle simulations by a self-made program have been carried out with a proton lattice designed for proton therapy.
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MOPRI093	Technical Design of Normal Conducting Re-buncher in the MEBT for Rare Isotope Science Project	830
	H.J. Kim, W.K. Han, I.S. Hong, D. Jeon IBS, Daejeon, Republic of Korea
	Funding: This work was supported by the RISP of Institute for Basic Science funded by Ministry of Science, ICT and Future Planning and National Research Foundation of Korea.(2011-0032011) The front-end system of RISP heavy-ion accelerator(RAON) consists of an electron cyclotron resonance ion source, a low energy beam transport line, a radio frequency quadrupole accelerator and a medium energy beam transport(MEBT) line. The MEBT system, which consists of quadrupole magnets, three normal-conducting re-bunchers and diagnostic devices, is installed between the RFQ accelerator and the superconducting linac(SCL). The three normal-conducting re-bunchers are used to minimize the growths of the longitudinal emittance and to manipulate the particle distribution on longitudinal phase space for beam transportation in SCL. Several combination of the number of cavities was examined, and the quarter wave resonator(QWR) type re-buncher was chosen for MEBT line in RAON. The QWR cavity has a frequency of 81.25 MHz, a maximum electric field of 2.53 MV/m on the cavity surface with an electric field of 1 MV/m on the beam axis, a geometrical beta factor of 0.032 and an effective length of 24 cm. In this presentation, I will present the results of baseline design for electro-magnetic field analysis and mechanical design for stress analysis, thermal stress analysis and cooling channel.
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MOPRI094	Proposal for a Slow Extraction System for a Biomedical Research Facility at CERN based on LEIR	833
	A. Garonna, D. Abler, C. Carli CERN, Geneva, Switzerland
	Funding: This work was partly funded by the Marie Curie Initial Training Network Fellowship of the European Community’s Seventh Framework Programme under contract number PITN-GA-2008-215840-PARTNER. A proposal has been made to accelerate ion beams ranging from hydrogen to neon with magnetic rigidities up to 6.7 Tm for biomedical experiments at CERN using the Low Energy Ion Ring (LEIR), in parallel to its continued operation for LHC and for SPS fixed target physics experiments. The feasibility of a new slow extraction system for LEIR based on the third integer resonance was studied with two possible resonance driving mechanisms: quadrupole-driven extraction and RF-knockout extraction. The extraction of fully stripped carbon ions (20-440 MeV/u kinetic energies) has been studied in detail. The requirement to keep the present performance of the machine for physics experiments imposes tight space constraints for the upgrade. The extraction scheme and the hardware requirements are described in this paper.
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MOPRI095	Study of Beam Transport Lines for a Biomedical Research Facility at CERN based on LEIR	836
SUSPSNE043	use link to see paper's listing under its alternate paper code
	D. Abler Oxford University, Physics Department, Oxford, Oxon, United Kingdom C. Carli, A. Garonna CERN, Geneva, Switzerland K.J. Peach JAI, Oxford, United Kingdom
	Funding: This work was supported by EU FP7 PARTNER (215840) and ULICE (228436). The Low Energy Ion Ring (LEIR) at CERN has been proposed to provide ion beams with magnetic rigidities up to 6.7 Tm for biomedical research, in parallel to its continued operation for LHC and SPS fixed target physics experiments. In the context of this project, two beamlines are proposed for transporting the extracted beam to future experimental end-stations: a vertical beamline for specific low-energy radiobiological research, and a horizontal beamline for radiobiology and medical physics experimentation. This study presents a first linear-optics design for the delivery of 1-5 mm FWHM pencil beams and 5 cm x 5 cm homogeneous broad beams to both endstations. High field uniformity is achieved by selection of the central part of a strongly defocused Gaussian beam, resulting in low beam utilisation.
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MOPRI096	The New Transfer Line Collimation System for the LHC High Luminosity Era	839
	V. Kain, C. Bracco, B. Goddard, F.L. Maciariello, M. Meddahi, A. Mereghetti, G.E. Steele, F.M. Velotti CERN, Geneva, Switzerland E. Gianfelice-Wendt Fermilab, Batavia, Illinois, USA
	A set of passive absorbers is located at the end of each of the 3 km long injection lines to protect the LHC in case of failures during the extraction process from the LHC’s last pre-injector or the beam transfer itself. In case of an erroneous extraction, the absorbers have to attenuate the beam to a safe level and be robust enough themselves to survive the impact. These requirements are difficult to fulfil with the very bright and intense beams produced by the LHC injectors for the high luminosity era. This paper revisits the requirements for the SPS-to-LHC transfer line collimation system and the adapted strategy to fulfill these for the LHC high luminosity operation. A possible solution for the new transfer line collimation system is presented.
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MOPRI097	Feasibility Studies for the Extraction of both LHC Beams from CERN SPS using a Common Kicker	842
	F.M. Velotti, W. Bartmann, C. Bracco, E. Carlier, K. Cornelis, B. Goddard, V. Kain, M. Meddahi CERN, Geneva, Switzerland
	The CERN Super Proton Synchrotron has to fulfil the demanding intensity specifications for the High Luminosity LHC (HL-LHC) era, with a doubling of the presently achieved operational beam intensity. One of the main problems to be addressed is given by impedance-driven beam instabilities. About 40 % of the total measured SPS impedance is due to the kickers, of which the extraction kickers in two of the SPS straight sections are the largest systems. A potential upgrade is explored which would strongly reduce the number of extraction kickers required in the SPS, by performing non-local extraction. In this scenario LHC Beam 1 would be kicked by the extraction kicker in SPS Long Straight Section 4 (LSS4), normally only used for Beam 2, to be extracted in LSS6. The concept and the expected performance of such a scheme are presented along with detailed simulation results.
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MOPRI098	Design Studies of the Upgraded Collimation System in the SPS-to-LHC Transfer Lines	845
	A. Mereghetti, C. Bracco, F. Cerutti, B. Goddard, J. Hrivnak, V. Kain, F.L. Maciariello, M. Meddahi, G.E. Steele CERN, Geneva, Switzerland R. Appleby UMAN, Manchester, United Kingdom
	In the framework of the LHC Injectors Upgrade (LIU) Project, the collimators in the SPS-to-LHC transfer lines are presently under re-design, in order to cope with the unprecedented beam intensities and emittances required by the High Luminosity LHC (HL-LHC). Factors ruling the design phase are the robustness of the jaws on one side and, on the other side, the proton absorption and the emittance blow-up, essential for an effective protection of the equipment in the LHC injection regions and the LHC machine. In view of the new design, based on the one of the currently installed TCDI collimators and past investigations, the FLUKA Monte Carlo code is used to address these two factors. The present studies are intended to give essential feedback to the identification of viable solutions.
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MOPRI101	Field Simulations and Mechanical Implementation of Electrostatic Elements for the ELENA Transfer Lines	855
	D. Barna University of Tokyo, Tokyo, Japan W. Bartmann, J. Borburgh, C. Carli, G. Vanbavinckhove CERN, Geneva, Switzerland
	The Antiproton Decelerator (AD) complex at CERN will be extended by an extra low energy anti-proton ring (ELENA) further decelerating the anti-protons thus improving their trapping. The kinetic energy of 100 keV at ELENA extraction facilitates the use of electrostatic transfer lines to the experiments. The mechanical implementation of the electrostatic devices are presented with focus on their alignment, bakeout compatibility, ultra-high vacuum compatibility and polarity switching. Field optimisations for an electrostatic crossing device of three beam lines are shown.
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MOPRI102	Upgrades of the CERN PS Booster Ejection Lines	858
	W. Bartmann, J.L. Abelleira, K. Hanke, M. Kowalska CERN, Geneva, Switzerland
	The PS Booster extraction energy will be augmented from 1.4 to 2 GeV to reduce intensity limits due to space charge at the PS proton injection. For this upgrade the transfer line between PS Booster and PS will be modified for 2 GeV operation and pulse to pulse optics modulation for different beam types. Also the PS Booster measurement line will also be upgraded to 2 GeV and shall provide improved optics solutions for emittance measurements while reducing the loss levels recorded during operation. This paper describes the foreseen optics solutions for both transfer lines.
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MOPRI103	Longitudinal Bunch Shortening for the Laser Stripping Project	861
	T.V. Gorlov, A.V. Aleksandrov, S.M. Cousineau, V.V. Danilov, Y. Liu, M.A. Plum ORNL, Oak Ridge, Tennessee, USA
	Funding: This work is funded by the U.S. DOE under grant number DE-FG02-13ER41967, and by the U.S. DOE under contract number DE-AC05-00OR22725 with UT-Battelle Corporation. Realization of high efficiency laser stripping at the SNS accelerator needs good longitudinal overlap between H⁻ bunch and laser pulse. The default H⁻ bunch length at the interaction point is 5 times bigger than needed in order to achieve 90% stripping efficiency. Theoretical and experimental studies of longitudinal H⁻ bunch shortening are presented in this paper.
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WEOBA03	Status of Preparations for a 10 μs Laser-Assisted H⁻ Beam Stripping Experiment	1864
	S.M. Cousineau, A.V. Aleksandrov, V.V. Danilov, T.V. Gorlov, Y. Liu, A.A. Menshov, M.A. Plum, A.P. Shishlo, Y. Wang ORNL, Oak Ridge, Tennessee, USA F.G. Garcia, N.F. Luttrell UTK, Knoxville, Tennessee, USA D.E. Johnson Fermilab, Batavia, Illinois, USA A. Rakhman ORNL RAD, Oak Ridge, Tennessee, USA Y. Takeda KEK, Ibaraki, Japan
	Funding: This work is funded by the U.S. DOE under grant number DE-FG02-13ER41967, and by the U.S. DOE under contract number DE-AC05-00OR22725 with UT-Battelle Corporation. The concept of laser-assisted H⁻ stripping, originated over three decades ago, was successfully demonstrated for a 6 ns, 900 MeV H⁻ beam in 2006. Plans are underway to build on this foundation by performing laser-assisted H⁻ stripping of a 10 μs, 1 GeV H⁻ beam at the Spallation Neutron Source facility; this constitutes a three orders of magnitude improvement over the initial proof of principle demonstration. The central theme of the experiment is the reduction of the required laser power through ion beam manipulations and laser-ion beam temporal matching. This paper discusses the configuration of the experiment, the current and anticipated challenges, and the schedule.
	Slides WEOBA03 [2.549 MB]
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Paper

Title

Page

Upgrade of the SPS Injection Kicker System for LHC High Luminosity Operation with Heavy Ion Beam

547

T. Kramer, J. Borburgh, L. Ducimetière, B. Goddard, L. Sermeus, J.A. Uythoven, F.M. Velotti
CERN, Geneva, Switzerland

In the context of the LHC High Luminosity Upgrade project a performance upgrade for heavy ions is envisaged. One of the performance limitations is the rise time of the present SPS injection kicker system MKP. A reduction of the rise time for lead ions was studied in line with a modification of the whole injection system. This paper briefly describes the different rise time options studied for an initially proposed dedicated ion kicker system MKP-I, focuses however on a cost effective alternative using the presently installed 12 MKPS magnets connected to a new fast pulse forming line. As only 12 out of the 16 injection kicker magnets would be fast enough to be used in an upgraded system, additional deflection has to be provided by the septa. The beam optics for that variant is highlighted and first requirements for the septum elements are stipulated. The paper concludes with a failure analysis of the proposed scheme.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPME076

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MOPRI087

Challenges of the Technical Layout of the SIS 100 Extraction System

815

N. Pyka, L.H.J. Bozyk, U. Kopf, C. Mühle, D. Ondreka, P. Rottländer, P.J. Spiller, St. Wilfert
GSI, Darmstadt, Germany
A.G. Kalimov
St. Petersburg State Polytechnic University, St. Petersburg, Russia

The FAIR synchrotron SIS100 which is under construction will provide heavy ion and proton beams of high intensity with fast and slow extraction. All extraction devices, including an internal emergency beam dump system, are installed within one straight section. This way, expected systematic beam loss is kept in a relatively small area of the synchrotron. In this area, it is rather challenging to protect components against high radiation fields, to keep XHV conditions, and to allow for maintenance of highly activated components to assure reliable beam operation. In this contribution, the technical measures to fulfill the requirements for the extraction straight section of SIS100 will be presented. These include remote controlled devices to move apart magnet yokes for the purpose of placing beam pipe heater; dedicated star-shaped vacuum chambers with integrated collimators and NEG-panels to reduce pressure bumps due to lost particles behind the electrostatic septa; a high-power multi-stage vertical extraction septum including a variable horizontal deflection.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-MOPRI087

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MOPRI088

Beam Transport Experiments Using Gabor Lenses

818

K. Schulte, M. Droba, S. Klaproth, O. Meusel, D. Noll, U. Ratzinger
IAP, Frankfurt am Main, Germany

A prototype Gabor lens has successfully been tested at the GSI High Current Test Injector (HOSTI)*. The experiments comprised the investigation of an emittance dominated and a space-charge dominated beam transport. In particular, the high-current measurements represent a necessary step towards evaluating the focusing performance of the lens and to gain experience in a real accelerator environment. Besides the evaluation of the technical feasibility, the behavior of the electron cloud was characterized by the parameter analysis of the confined non-neutral plasma during beam transport measurements as well as subsequently performed diagnostic experiments. This contribution will present experimental results as well as numerical studies on an improved Gabor lens design for the possible application at the GSI High Current Injector (HSI) in the context of an upgrade program for FAIR**.
*K. Schulte et al., Proc. of IPAC'13, Shanghai, China, 2013, THPWO021
**L. Dahl, Proc. of HIAT’09, Venice, Italy, 2009, FR-01

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MOPRI089

Upgrade of J-PARC Fast Extraction System

821

K. Fan, K. Ishii, H. Matsumoto, N. Matsumoto, T. Sugimoto
KEK, Ibaraki, Japan
T. Shibata
JAEA, Ibaraki-ken, Japan

The J-PARC main ring (MR) fast extraction (FX) system has two functions: to deliver a high power beam to the neutrino experimental facility and to dump the beam at any time in case of hardware failures. The present FX system consists of five bipolar kickers and eight bipolar septa. In order to raise the beam power to the design limit, both the beam intensity and the repetition rate will increase gradually. The FX system needs to be upgraded to satisfy the new requirements. The upgrade includes FX orbit optimization and new design of devices. Firstly, two high performance eddy current septa have been designed and fabricated. Then downstream high field septa are redesigned and using ceramic beam pipe to eliminate eddy current effects, which meets the requirement of high repetition rate operation. A new large physical aperture quadrupole is needed to accommodate high intensity beam. In order to evaluate the beam loss in the new system, realistic 3D beam tracking is studied.

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MOPRI090

Beam Distribution Transformation with SFMs at 3MeV C-ADS Beamline

824

H. Geng, P. Cheng, C. Meng, S. Pei, B. Sun, H.J. Wang, B. Xu, F. Yan, Y.L. Zhao
IHEP, Beijing, People's Republic of China

The C-ADS project is building a test facility at the Institute of High Energy Physics. The design goal of the test facility is 10MeV beam energy with a continuous beam current of 10mA. To sustain the 100kW CW beam power at the beam dump, a beam distribution transform system is designed. The Step Field Magnets (SFMs) are used to transform the beam distribution from Gaussian to uniform. In this test stand, two sets of SFMs will be employed to manipulate the beam distribution. At the first commissioning stage, the bump dump line will be connected to the Medium Energy Beam Transport-1 (MEBT1) to test the beam manipulation scheme. The design and error analysis of this 3MeV beam dump line will be discussed in this paper.

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MOPRI091

Resonant Slow Extraction in Synchrotrons by Using Anti-symmetric Sextupole Fields

827

SUSPSNE044

use link to see paper's listing under its alternate paper code

Y. Zou, J.Y. Tang
IHEP, Beijing, People's Republic of China

This paper proposes a novel method for non-resonant slow extraction by using special anti-symmetric sextupole field in synchrotrons. The method has the potential in applications asking for stable slow extraction and in the halo collimation of very large machine such as LHC. Our studies show that the slow extraction by using anti-symmetric sextupole field has some advantages compared to the normal sextupole field which is the normal extraction method. One of them is that it can work at almost arbitrary tune, so that it can avoid the problem of the intensity variation caused by the ripples of magnet supplies. Studies by Hamiltonian theory and simulations which meet well show that the stable region only depends on the anti-symmetric sextupole field strength and the particles outside will be driven out in two directions which are similar to the second-order resonant extraction but with spiral steps as in the third-order resonance extraction. The beam can be extracted with a very stable intensity by gradually increasing the field strength. The multi-particle simulations by a self-made program have been carried out with a proton lattice designed for proton therapy.

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MOPRI093

Technical Design of Normal Conducting Re-buncher in the MEBT for Rare Isotope Science Project

830

H.J. Kim, W.K. Han, I.S. Hong, D. Jeon
IBS, Daejeon, Republic of Korea

Funding: This work was supported by the RISP of Institute for Basic Science funded by Ministry of Science, ICT and Future Planning and National Research Foundation of Korea.(2011-0032011)
The front-end system of RISP heavy-ion accelerator(RAON) consists of an electron cyclotron resonance ion source, a low energy beam transport line, a radio frequency quadrupole accelerator and a medium energy beam transport(MEBT) line. The MEBT system, which consists of quadrupole magnets, three normal-conducting re-bunchers and diagnostic devices, is installed between the RFQ accelerator and the superconducting linac(SCL). The three normal-conducting re-bunchers are used to minimize the growths of the longitudinal emittance and to manipulate the particle distribution on longitudinal phase space for beam transportation in SCL. Several combination of the number of cavities was examined, and the quarter wave resonator(QWR) type re-buncher was chosen for MEBT line in RAON. The QWR cavity has a frequency of 81.25 MHz, a maximum electric field of 2.53 MV/m on the cavity surface with an electric field of 1 MV/m on the beam axis, a geometrical beta factor of 0.032 and an effective length of 24 cm. In this presentation, I will present the results of baseline design for electro-magnetic field analysis and mechanical design for stress analysis, thermal stress analysis and cooling channel.

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MOPRI094

Proposal for a Slow Extraction System for a Biomedical Research Facility at CERN based on LEIR

833

A. Garonna, D. Abler, C. Carli
CERN, Geneva, Switzerland

Funding: This work was partly funded by the Marie Curie Initial Training Network Fellowship of the European Community’s Seventh Framework Programme under contract number PITN-GA-2008-215840-PARTNER.
A proposal has been made to accelerate ion beams ranging from hydrogen to neon with magnetic rigidities up to 6.7 Tm for biomedical experiments at CERN using the Low Energy Ion Ring (LEIR), in parallel to its continued operation for LHC and for SPS fixed target physics experiments. The feasibility of a new slow extraction system for LEIR based on the third integer resonance was studied with two possible resonance driving mechanisms: quadrupole-driven extraction and RF-knockout extraction. The extraction of fully stripped carbon ions (20-440 MeV/u kinetic energies) has been studied in detail. The requirement to keep the present performance of the machine for physics experiments imposes tight space constraints for the upgrade. The extraction scheme and the hardware requirements are described in this paper.

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MOPRI095

Study of Beam Transport Lines for a Biomedical Research Facility at CERN based on LEIR

836

SUSPSNE043

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D. Abler
Oxford University, Physics Department, Oxford, Oxon, United Kingdom
C. Carli, A. Garonna
CERN, Geneva, Switzerland
K.J. Peach
JAI, Oxford, United Kingdom

Funding: This work was supported by EU FP7 PARTNER (215840) and ULICE (228436).
The Low Energy Ion Ring (LEIR) at CERN has been proposed to provide ion beams with magnetic rigidities up to 6.7 Tm for biomedical research, in parallel to its continued operation for LHC and SPS fixed target physics experiments. In the context of this project, two beamlines are proposed for transporting the extracted beam to future experimental end-stations: a vertical beamline for specific low-energy radiobiological research, and a horizontal beamline for radiobiology and medical physics experimentation. This study presents a first linear-optics design for the delivery of 1-5 mm FWHM pencil beams and 5 cm x 5 cm homogeneous broad beams to both endstations. High field uniformity is achieved by selection of the central part of a strongly defocused Gaussian beam, resulting in low beam utilisation.

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MOPRI096

The New Transfer Line Collimation System for the LHC High Luminosity Era

839

V. Kain, C. Bracco, B. Goddard, F.L. Maciariello, M. Meddahi, A. Mereghetti, G.E. Steele, F.M. Velotti
CERN, Geneva, Switzerland
E. Gianfelice-Wendt
Fermilab, Batavia, Illinois, USA

A set of passive absorbers is located at the end of each of the 3 km long injection lines to protect the LHC in case of failures during the extraction process from the LHC’s last pre-injector or the beam transfer itself. In case of an erroneous extraction, the absorbers have to attenuate the beam to a safe level and be robust enough themselves to survive the impact. These requirements are difficult to fulfil with the very bright and intense beams produced by the LHC injectors for the high luminosity era. This paper revisits the requirements for the SPS-to-LHC transfer line collimation system and the adapted strategy to fulfill these for the LHC high luminosity operation. A possible solution for the new transfer line collimation system is presented.

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MOPRI097

Feasibility Studies for the Extraction of both LHC Beams from CERN SPS using a Common Kicker

842

F.M. Velotti, W. Bartmann, C. Bracco, E. Carlier, K. Cornelis, B. Goddard, V. Kain, M. Meddahi
CERN, Geneva, Switzerland

The CERN Super Proton Synchrotron has to fulfil the demanding intensity specifications for the High Luminosity LHC (HL-LHC) era, with a doubling of the presently achieved operational beam intensity. One of the main problems to be addressed is given by impedance-driven beam instabilities. About 40 % of the total measured SPS impedance is due to the kickers, of which the extraction kickers in two of the SPS straight sections are the largest systems. A potential upgrade is explored which would strongly reduce the number of extraction kickers required in the SPS, by performing non-local extraction. In this scenario LHC Beam 1 would be kicked by the extraction kicker in SPS Long Straight Section 4 (LSS4), normally only used for Beam 2, to be extracted in LSS6. The concept and the expected performance of such a scheme are presented along with detailed simulation results.

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MOPRI098

Design Studies of the Upgraded Collimation System in the SPS-to-LHC Transfer Lines

845

A. Mereghetti, C. Bracco, F. Cerutti, B. Goddard, J. Hrivnak, V. Kain, F.L. Maciariello, M. Meddahi, G.E. Steele
CERN, Geneva, Switzerland
R. Appleby
UMAN, Manchester, United Kingdom

In the framework of the LHC Injectors Upgrade (LIU) Project, the collimators in the SPS-to-LHC transfer lines are presently under re-design, in order to cope with the unprecedented beam intensities and emittances required by the High Luminosity LHC (HL-LHC). Factors ruling the design phase are the robustness of the jaws on one side and, on the other side, the proton absorption and the emittance blow-up, essential for an effective protection of the equipment in the LHC injection regions and the LHC machine. In view of the new design, based on the one of the currently installed TCDI collimators and past investigations, the FLUKA Monte Carlo code is used to address these two factors. The present studies are intended to give essential feedback to the identification of viable solutions.

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MOPRI101

Field Simulations and Mechanical Implementation of Electrostatic Elements for the ELENA Transfer Lines

855

D. Barna
University of Tokyo, Tokyo, Japan
W. Bartmann, J. Borburgh, C. Carli, G. Vanbavinckhove
CERN, Geneva, Switzerland

The Antiproton Decelerator (AD) complex at CERN will be extended by an extra low energy anti-proton ring (ELENA) further decelerating the anti-protons thus improving their trapping. The kinetic energy of 100 keV at ELENA extraction facilitates the use of electrostatic transfer lines to the experiments. The mechanical implementation of the electrostatic devices are presented with focus on their alignment, bakeout compatibility, ultra-high vacuum compatibility and polarity switching. Field optimisations for an electrostatic crossing device of three beam lines are shown.

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MOPRI102

Upgrades of the CERN PS Booster Ejection Lines

858

W. Bartmann, J.L. Abelleira, K. Hanke, M. Kowalska
CERN, Geneva, Switzerland

The PS Booster extraction energy will be augmented from 1.4 to 2 GeV to reduce intensity limits due to space charge at the PS proton injection. For this upgrade the transfer line between PS Booster and PS will be modified for 2 GeV operation and pulse to pulse optics modulation for different beam types. Also the PS Booster measurement line will also be upgraded to 2 GeV and shall provide improved optics solutions for emittance measurements while reducing the loss levels recorded during operation. This paper describes the foreseen optics solutions for both transfer lines.

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MOPRI103

Longitudinal Bunch Shortening for the Laser Stripping Project

861

T.V. Gorlov, A.V. Aleksandrov, S.M. Cousineau, V.V. Danilov, Y. Liu, M.A. Plum
ORNL, Oak Ridge, Tennessee, USA

Funding: This work is funded by the U.S. DOE under grant number DE-FG02-13ER41967, and by the U.S. DOE under contract number DE-AC05-00OR22725 with UT-Battelle Corporation.
Realization of high efficiency laser stripping at the SNS accelerator needs good longitudinal overlap between H⁻ bunch and laser pulse. The default H⁻ bunch length at the interaction point is 5 times bigger than needed in order to achieve 90% stripping efficiency. Theoretical and experimental studies of longitudinal H⁻ bunch shortening are presented in this paper.

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WEOBA03

Status of Preparations for a 10 μs Laser-Assisted H⁻ Beam Stripping Experiment

1864

S.M. Cousineau, A.V. Aleksandrov, V.V. Danilov, T.V. Gorlov, Y. Liu, A.A. Menshov, M.A. Plum, A.P. Shishlo, Y. Wang
ORNL, Oak Ridge, Tennessee, USA
F.G. Garcia, N.F. Luttrell
UTK, Knoxville, Tennessee, USA
D.E. Johnson
Fermilab, Batavia, Illinois, USA
A. Rakhman
ORNL RAD, Oak Ridge, Tennessee, USA
Y. Takeda
KEK, Ibaraki, Japan

Funding: This work is funded by the U.S. DOE under grant number DE-FG02-13ER41967, and by the U.S. DOE under contract number DE-AC05-00OR22725 with UT-Battelle Corporation.
The concept of laser-assisted H⁻ stripping, originated over three decades ago, was successfully demonstrated for a 6 ns, 900 MeV H⁻ beam in 2006. Plans are underway to build on this foundation by performing laser-assisted H⁻ stripping of a 10 μs, 1 GeV H⁻ beam at the Spallation Neutron Source facility; this constitutes a three orders of magnitude improvement over the initial proof of principle demonstration. The central theme of the experiment is the reduction of the required laser power through ion beam manipulations and laser-ion beam temporal matching. This paper discusses the configuration of the experiment, the current and anticipated challenges, and the schedule.

Slides WEOBA03 [2.549 MB]

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