DIPAC2011 - List of Keywords (rfq)

Paper	Title	Other Keywords	Page
MOPD35	Improved Signal Treatment for Capacitive Linac Pick-Ups	pick-up, DTL, linac, radio-frequency	128
	A. Reiter, C.M. Kleffner, B. Schlitt GSI, Darmstadt, Germany
	Phase probes are a crucial diagnostic tool for pulsed particle beams of linear accelerators. In this contribution we present a simple, but very effective analysis procedure which has been established in various applications during commissioning campaigns of injector linacs for medical facilities. These injectors consist of a 400 keV/u radio-frequency quadrupole followed by a 7 MeV/u inter-digital drift tube linac, both operating at 216.8 MHz. At GSI, the new analysis was recently applied at the HITRAP decelerator, also with promising results. The data analysis exploits the periodic nature of sampling process and bunch signal improving the detector sensitivity and achieving an effective resolution of < 10 ps. If the macro-pulse is sufficiently long, the quality of the data can be improved further by a statistical average of subsequent data blocks acquired within one single macro-pulse. The latter is important for experiments with low beam intensity and low repetition rate like HITRAP where averaging over many macro-pulses is cumbersome.

MOPD36	Development of a Silicon Detector Monitor for the Superconducting Upgrade of the REX-ISOLDE Heavy-Ion Linac at CERN	linac, cavity, ion, diagnostics	131
	F. Zocca IEM, Madrid, Spain E. Bravin, M.A. Fraser, D. Voulot, F.J.C. Wenander, F. Zocca CERN, Geneva, Switzerland M. Pasini Instituut voor Kern- en Stralingsfysica, K. U. Leuven, Leuven, Belgium
	A silicon detector monitor has been developed and tested in the frame of the beam diagnostics development program for the HIE-ISOLDE superconducting upgrade of the REX-ISOLDE heavy-ion linac at CERN. The monitor is intended for beam energy and timing measurements as well as for phase scanning of the superconducting cavities. Tests have been performed with a stable ion beam, composed of carbon, oxygen and neon ions accelerated to energies from 300 keV/u to 2.85 MeV/u. The silicon detector was placed directly in the beam line and tested with a beam which was strongly attenuated to simulate the single particle detection regime for which the monitor is intended to finally function. The energy measurements performed allowed for beam spectroscopy and ion identification with a resolution of 3%. The principle of cavity phase scanning was also demonstrated with the REX 7-gap resonator thanks to the accurate peak energy identification. The time structure of the beam, characterized by a bunch period of 9.87 ns, was measured with a resolution better than 200 ps. This paper describes the results from all these tests as well as providing details of the detector.

MOPD52	First Results from Beam Measurements at the 3 MeV Test Stand for CERN Linac4	emittance, solenoid, linac, proton	167
	B. Cheymol, J.-B. Lallement, A.E. Lokhovitskiy, O. Midttun, U. Raich, F. Roncarolo, R. Scrivens, E. Zorin CERN, Geneva, Switzerland B. Cheymol Université Blaise Pascal, Clermont-Ferrand, France
	The H⁻ source and the low energy beam line will determine to a large extend the performance of Linac-4, the new machine foreseen as injector into the PS Booster. For this reason a test stand will be set up consisting of the source, Low Energy Beam Transport (LEBT), RFQ and chopper line. Up to now only the source and LEBT are installed. First measurements have been performed using a Faraday Cup to measure the total source intensity, a slit-&-grid emittance meter for transverse emittance measurements and a spectrometer for energy spread measurements. This paper discusses the results from measurements on H⁻ beams at 35kV extraction voltage as well as protons at 45 kV, showing the emittance dependence on source RF power as well as the influence of a solenoid in splitting the beam into its various constituents: protons, H0, H²⁺ and H³⁺. Energy spread measurements are also presented.

MOPD85	Beam Emittance Studies at the Heavy Ion Linac UNILAC	emittance, ion, linac, DTL	245
	P. Gerhard, W.A. Barth, L.A. Dahl, L. Groening, H. Vormann GSI, Darmstadt, Germany
	New accelerating structures for the UNILAC at GSI were commissioned in the last two years [1, 2], and major machine upgrades in order to meet the requirements for FAIR are in preparation [3, 4]. Beam emittance is one of the key beam parameters that are essential for any beam dynamics calculation, for the design of new accelerators as well as verification or investigation of existing machines. Its measurement is intricate and often time consuming. Extensive emittance measurements went along with the commissionings and were conducted to provide a reliable basis for beam dynamics simulations. In addition to the 10 permanent transverse emittance measurement devices installed all over the UNILAC, two "mobile" devices had been built and mounted at four different sites in the UNILAC. This work shows the standard slid-grid device used for transverse beam emittance measurements and gives an overview of the activities and results. The following topics will be presented with respect to design studies and simulations: Emittance growth of high current ion beams along the UNILAC, stripping, and resonance effects. [1] H. Vormann et al., LINAC10, MOP040 [2] P. Gerhard et al., IPAC10, MOPD028 [3] W. Barth et al., PAC09, FR5REP059 [4] S. Mickat et al., LINAC10, MOP042
	Poster MOPD85 [10.077 MB]

TUOA03	The Fermilab HINS Test Facility and Beam Measurements of the Ion Source and 325 MHz RFQ	diagnostics, proton, laser, linac	283
	V.E. Scarpine, S. Chaurize, B.M. Hanna, S. Hays, J. Steimel, R.C. Webber, D. Wildman Fermilab, Batavia, USA
	Funding: This work was supported by the U.S. Department of Energy under contract No. DE-AC02-07CH11359. The Fermilab High Intensity Neutrino Source (HINS) project is intended to test new concepts for low-energy, high-intensity superconducting linacs. HINS initial design consists of a 50 KeV ion source, a 2.5 MeV Radiofrequency Quadrupole (RFQ) followed by room temperature and superconducting spoke resonator acceleration sections. At present, a proton ion source and the 325 MHz RFQ, followed by a beam diagnostics section, have been operated with beam. This paper will present the beam measurement results for the proton ion source and for the 325 MHz RFQ module. In addition, this paper will discuss the role of HINS as a test facility for the development of beam diagnostic instrumentation required for future high-intensity linacs.
	Slides TUOA03 [1.864 MB]

TUPD05	Diagnostic Scheme for the HITRAP Decelerator	ion, pick-up, diagnostics, dipole	311
	G. Vorobjev, C.A. Andre, W.A. Barth, E. Berdermann, M.I. Ciobanu, G. Clemente, L.A. Dahl, P. Forck, P. Gerhard, R. Haseitl, F. Herfurth, M. Kaiser, W. Kaufmann, H.J. Kluge, N. Kotovski, C. Kozhuharov, M.T. Maier, W. Quint, A. Reiter, A. Sokolov, T. Stöhlker GSI, Darmstadt, Germany O.K. Kester, J. Pfister, U. Ratzinger, A. Schempp IAP, Frankfurt am Main, Germany
	The HITRAP linear decelerator currently being set up at GSI will provide slow, few keV/u highly charged ions for atomic physics experiments. The expected beam intensity is up to 10⁵ ions per shot. To optimize phase and amplitude of the RF systems intensity, bunch length and kinetic energy of the particles need to be monitored. The bunch length that we need to fit is about 2 ns, which is typically measured by capacitive pickups. However, they do not work for the low beam intensities that we face. We investigated the bunch length with a fast CVD diamond detector working in single particle counting mode. Averaging over 8 shots yields a clear, regular picture of the bunched beam. Energy measurements by capacitive pickups are limited by the presence of intense primary and partially decelerated beam and hence make tuning of the IH-structure impossible. The energy of the decelerated fraction of the beam behind the first deceleration cavity was determined to about 10 % accuracy with a permanent dipole magnet combined with a MCP. Better detector calibration should help reaching the required 1%. Design of the detectors as well as the results of the measurements will be presented.

TUPD17	Spatial Resolution Test of a BPMS for DESIREE Beam Line Diagnostics	ion, electron, diagnostics, simulation	338
	S. Das, A. Källberg MSL, Stockholm, Sweden J. Harasimowicz The University of Liverpool, Liverpool, United Kingdom
	Funding: Two of us (S.Das and J. Harasimowicz) acknowledge the financial support received from the European Commission within FP7 Marie Curie Initial Training Network DITANET Spatial resolution of a beam profile monitoring system (BPMS) was tested. It will be a part of the DESIREE [1] diagnostics to monitor and cover the wide range of beam intensities and energies. The BPMS consists of an aluminum (Al) plate, a grid placed in front of Al, a microchannel plate (MCP), a fluorescent screen (F.S.), a PC, and a CCD camera [2]. A beam collimator containing a set of circular holes of different diameter and separation between them was built to check the spatial resolution of the system [3]. Two holes of diameter 1 mm, separated by 2 mm, in the collimator were used for this purpose. A proton beam was used for the measurements. It was observed that these holes create two beams of approximately same intensity of areas each of 1 mm in diameter with 2 mm separation between the beam centers on the screen, suggesting a resolution of 2 mm of the system. The resolution was tested for different beam energy (0.5-40 keV), and voltages applied on the Al and MCP plates. The experimental results will be compared with the simulations. [1] www.msl.se;www.atom.physto.se/Cederquist/desiree_web_hc.html [2] K. Kruglov et al, NIM A, 441, 595 (2002);Nucl. Phys. A, 701, 193c (2002) [3] S. Das et al, Proceedíngs of DITANET workshop, Nov. 23-25, 2009

TUPD65	Four-Dimensional Transverse Emittance Measurement Unit for High Intensity Ion Beams	emittance, ion, background, vacuum	455
	S.X. Peng, J.E. Chen, Z.Y. Guo, P.N. Lu, Y.R. Lu, Z.X. Yuan, J. Zhao PKU/IHIP, Beijing, People's Republic of China H.T. Ren Graduate University, Chinese Academy of Sciences, Beijing, People's Republic of China
	Funding: National Natural Science Foundation of China An X-Y coplaner High Intensity Beam Emittance Measurement Unit named as HIBEMU-4 has been developed recently to measure the emmitance of 2 MeV/40mA D⁺ beam at the RFQ exit of PeKing University Neutron Imaging FaciliTY (PKUNIFTY). HIBEMU-4 is based on the slit-wire method, and has two groups of slits in the orthogonal directions. Equipped with user-oriented software, it is able to provide results as root-mean-square(rms) emittance, boundary emittance, Twiss-parameters and phase diagram. In this paper we will mainly discuss the strengths and limitations of HIBEMU-4 at the aspects of mechanical designing and data processing method. In addition the testing of HIBEMU-4 on 1MeV O+ beam as well as 2 MeV/40mA D⁺ is closely presented, which shows HIBEMU-4 is competent in high intensity beam (HIB) emmitance measurements.

TUPD92	SPIRAL2 Beam Energy Measurement	pick-up, simulation, linac, instrumentation	524
	W. Le Coz, T.A. André, C. Doutresssoulles, C. Jamet, S. Loret GANIL, Caen, France
	In order to produce high intensity exotic beams in the existing experimental rooms of the GANIL facility, the SPIRAL2 project is under development and under construction at GANIL. The first phase of the SPIRAL2 project consists to build a new accelerator composed of two sources, an ion source and a proton/neutron source, a RFQ and a superconducting Linac. The linac is designed to accelerate 5 mA deuterons up to 40 MeV and 1 mA heavy ions up to 14.5 MeV/u. A new electronic device has been developed at GANIL to measure phase and amplitude of pick-up signals and calculate the beam energy. The principle consists of directly digitizing the pick-up pulses by under-sampling. The Phase and amplitude of different harmonics are then calculated with a FPGA by an I/Q method before the beam energy calculation. This paper gives results of the peak-up tests in laboratory and the comparisons with simulations. The tests in laboratory and on the GANIL accelerator of an electronic prototype are shown and presented.

Paper

Title

Other Keywords

Page

MOPD35

Improved Signal Treatment for Capacitive Linac Pick-Ups

pick-up, DTL, linac, radio-frequency

128

A. Reiter, C.M. Kleffner, B. Schlitt
GSI, Darmstadt, Germany

Phase probes are a crucial diagnostic tool for pulsed particle beams of linear accelerators. In this contribution we present a simple, but very effective analysis procedure which has been established in various applications during commissioning campaigns of injector linacs for medical facilities. These injectors consist of a 400 keV/u radio-frequency quadrupole followed by a 7 MeV/u inter-digital drift tube linac, both operating at 216.8 MHz. At GSI, the new analysis was recently applied at the HITRAP decelerator, also with promising results. The data analysis exploits the periodic nature of sampling process and bunch signal improving the detector sensitivity and achieving an effective resolution of < 10 ps. If the macro-pulse is sufficiently long, the quality of the data can be improved further by a statistical average of subsequent data blocks acquired within one single macro-pulse. The latter is important for experiments with low beam intensity and low repetition rate like HITRAP where averaging over many macro-pulses is cumbersome.

MOPD36

Development of a Silicon Detector Monitor for the Superconducting Upgrade of the REX-ISOLDE Heavy-Ion Linac at CERN

linac, cavity, ion, diagnostics

131

F. Zocca
IEM, Madrid, Spain
E. Bravin, M.A. Fraser, D. Voulot, F.J.C. Wenander, F. Zocca
CERN, Geneva, Switzerland
M. Pasini
Instituut voor Kern- en Stralingsfysica, K. U. Leuven, Leuven, Belgium

A silicon detector monitor has been developed and tested in the frame of the beam diagnostics development program for the HIE-ISOLDE superconducting upgrade of the REX-ISOLDE heavy-ion linac at CERN. The monitor is intended for beam energy and timing measurements as well as for phase scanning of the superconducting cavities. Tests have been performed with a stable ion beam, composed of carbon, oxygen and neon ions accelerated to energies from 300 keV/u to 2.85 MeV/u. The silicon detector was placed directly in the beam line and tested with a beam which was strongly attenuated to simulate the single particle detection regime for which the monitor is intended to finally function. The energy measurements performed allowed for beam spectroscopy and ion identification with a resolution of 3%. The principle of cavity phase scanning was also demonstrated with the REX 7-gap resonator thanks to the accurate peak energy identification. The time structure of the beam, characterized by a bunch period of 9.87 ns, was measured with a resolution better than 200 ps. This paper describes the results from all these tests as well as providing details of the detector.

MOPD52

First Results from Beam Measurements at the 3 MeV Test Stand for CERN Linac4

emittance, solenoid, linac, proton

167

B. Cheymol, J.-B. Lallement, A.E. Lokhovitskiy, O. Midttun, U. Raich, F. Roncarolo, R. Scrivens, E. Zorin
CERN, Geneva, Switzerland
B. Cheymol
Université Blaise Pascal, Clermont-Ferrand, France

The H⁻ source and the low energy beam line will determine to a large extend the performance of Linac-4, the new machine foreseen as injector into the PS Booster. For this reason a test stand will be set up consisting of the source, Low Energy Beam Transport (LEBT), RFQ and chopper line. Up to now only the source and LEBT are installed. First measurements have been performed using a Faraday Cup to measure the total source intensity, a slit-&-grid emittance meter for transverse emittance measurements and a spectrometer for energy spread measurements. This paper discusses the results from measurements on H⁻ beams at 35kV extraction voltage as well as protons at 45 kV, showing the emittance dependence on source RF power as well as the influence of a solenoid in splitting the beam into its various constituents: protons, H0, H²⁺ and H³⁺. Energy spread measurements are also presented.

MOPD85

Beam Emittance Studies at the Heavy Ion Linac UNILAC

emittance, ion, linac, DTL

245

P. Gerhard, W.A. Barth, L.A. Dahl, L. Groening, H. Vormann
GSI, Darmstadt, Germany

New accelerating structures for the UNILAC at GSI were commissioned in the last two years [1, 2], and major machine upgrades in order to meet the requirements for FAIR are in preparation [3, 4]. Beam emittance is one of the key beam parameters that are essential for any beam dynamics calculation, for the design of new accelerators as well as verification or investigation of existing machines. Its measurement is intricate and often time consuming. Extensive emittance measurements went along with the commissionings and were conducted to provide a reliable basis for beam dynamics simulations. In addition to the 10 permanent transverse emittance measurement devices installed all over the UNILAC, two "mobile" devices had been built and mounted at four different sites in the UNILAC. This work shows the standard slid-grid device used for transverse beam emittance measurements and gives an overview of the activities and results. The following topics will be presented with respect to design studies and simulations: Emittance growth of high current ion beams along the UNILAC, stripping, and resonance effects.
[1] H. Vormann et al., LINAC10, MOP040
[2] P. Gerhard et al., IPAC10, MOPD028
[3] W. Barth et al., PAC09, FR5REP059
[4] S. Mickat et al., LINAC10, MOP042

Poster MOPD85 [10.077 MB]

TUOA03

The Fermilab HINS Test Facility and Beam Measurements of the Ion Source and 325 MHz RFQ

diagnostics, proton, laser, linac

283

V.E. Scarpine, S. Chaurize, B.M. Hanna, S. Hays, J. Steimel, R.C. Webber, D. Wildman
Fermilab, Batavia, USA

Funding: This work was supported by the U.S. Department of Energy under contract No. DE-AC02-07CH11359.
The Fermilab High Intensity Neutrino Source (HINS) project is intended to test new concepts for low-energy, high-intensity superconducting linacs. HINS initial design consists of a 50 KeV ion source, a 2.5 MeV Radiofrequency Quadrupole (RFQ) followed by room temperature and superconducting spoke resonator acceleration sections. At present, a proton ion source and the 325 MHz RFQ, followed by a beam diagnostics section, have been operated with beam. This paper will present the beam measurement results for the proton ion source and for the 325 MHz RFQ module. In addition, this paper will discuss the role of HINS as a test facility for the development of beam diagnostic instrumentation required for future high-intensity linacs.

Slides TUOA03 [1.864 MB]

TUPD05

Diagnostic Scheme for the HITRAP Decelerator

ion, pick-up, diagnostics, dipole

311

G. Vorobjev, C.A. Andre, W.A. Barth, E. Berdermann, M.I. Ciobanu, G. Clemente, L.A. Dahl, P. Forck, P. Gerhard, R. Haseitl, F. Herfurth, M. Kaiser, W. Kaufmann, H.J. Kluge, N. Kotovski, C. Kozhuharov, M.T. Maier, W. Quint, A. Reiter, A. Sokolov, T. Stöhlker
GSI, Darmstadt, Germany
O.K. Kester, J. Pfister, U. Ratzinger, A. Schempp
IAP, Frankfurt am Main, Germany

The HITRAP linear decelerator currently being set up at GSI will provide slow, few keV/u highly charged ions for atomic physics experiments. The expected beam intensity is up to 10⁵ ions per shot. To optimize phase and amplitude of the RF systems intensity, bunch length and kinetic energy of the particles need to be monitored. The bunch length that we need to fit is about 2 ns, which is typically measured by capacitive pickups. However, they do not work for the low beam intensities that we face. We investigated the bunch length with a fast CVD diamond detector working in single particle counting mode. Averaging over 8 shots yields a clear, regular picture of the bunched beam. Energy measurements by capacitive pickups are limited by the presence of intense primary and partially decelerated beam and hence make tuning of the IH-structure impossible. The energy of the decelerated fraction of the beam behind the first deceleration cavity was determined to about 10 % accuracy with a permanent dipole magnet combined with a MCP. Better detector calibration should help reaching the required 1%. Design of the detectors as well as the results of the measurements will be presented.

TUPD17

Spatial Resolution Test of a BPMS for DESIREE Beam Line Diagnostics

ion, electron, diagnostics, simulation

338

S. Das, A. Källberg
MSL, Stockholm, Sweden
J. Harasimowicz
The University of Liverpool, Liverpool, United Kingdom

Funding: Two of us (S.Das and J. Harasimowicz) acknowledge the financial support received from the European Commission within FP7 Marie Curie Initial Training Network DITANET
Spatial resolution of a beam profile monitoring system (BPMS) was tested. It will be a part of the DESIREE [1] diagnostics to monitor and cover the wide range of beam intensities and energies. The BPMS consists of an aluminum (Al) plate, a grid placed in front of Al, a microchannel plate (MCP), a fluorescent screen (F.S.), a PC, and a CCD camera [2]. A beam collimator containing a set of circular holes of different diameter and separation between them was built to check the spatial resolution of the system [3]. Two holes of diameter 1 mm, separated by 2 mm, in the collimator were used for this purpose. A proton beam was used for the measurements. It was observed that these holes create two beams of approximately same intensity of areas each of 1 mm in diameter with 2 mm separation between the beam centers on the screen, suggesting a resolution of 2 mm of the system. The resolution was tested for different beam energy (0.5-40 keV), and voltages applied on the Al and MCP plates. The experimental results will be compared with the simulations.
[1] www.msl.se;www.atom.physto.se/Cederquist/desiree_web_hc.html
[2] K. Kruglov et al, NIM A, 441, 595 (2002);Nucl. Phys. A, 701, 193c (2002)
[3] S. Das et al, Proceedíngs of DITANET workshop, Nov. 23-25, 2009

TUPD65

Four-Dimensional Transverse Emittance Measurement Unit for High Intensity Ion Beams

emittance, ion, background, vacuum

455

S.X. Peng, J.E. Chen, Z.Y. Guo, P.N. Lu, Y.R. Lu, Z.X. Yuan, J. Zhao
PKU/IHIP, Beijing, People's Republic of China
H.T. Ren
Graduate University, Chinese Academy of Sciences, Beijing, People's Republic of China

Funding: National Natural Science Foundation of China
An X-Y coplaner High Intensity Beam Emittance Measurement Unit named as HIBEMU-4 has been developed recently to measure the emmitance of 2 MeV/40mA D⁺ beam at the RFQ exit of PeKing University Neutron Imaging FaciliTY (PKUNIFTY). HIBEMU-4 is based on the slit-wire method, and has two groups of slits in the orthogonal directions. Equipped with user-oriented software, it is able to provide results as root-mean-square(rms) emittance, boundary emittance, Twiss-parameters and phase diagram. In this paper we will mainly discuss the strengths and limitations of HIBEMU-4 at the aspects of mechanical designing and data processing method. In addition the testing of HIBEMU-4 on 1MeV O+ beam as well as 2 MeV/40mA D⁺ is closely presented, which shows HIBEMU-4 is competent in high intensity beam (HIB) emmitance measurements.

TUPD92

SPIRAL2 Beam Energy Measurement

pick-up, simulation, linac, instrumentation

524

W. Le Coz, T.A. André, C. Doutresssoulles, C. Jamet, S. Loret
GANIL, Caen, France

In order to produce high intensity exotic beams in the existing experimental rooms of the GANIL facility, the SPIRAL2 project is under development and under construction at GANIL. The first phase of the SPIRAL2 project consists to build a new accelerator composed of two sources, an ion source and a proton/neutron source, a RFQ and a superconducting Linac. The linac is designed to accelerate 5 mA deuterons up to 40 MeV and 1 mA heavy ions up to 14.5 MeV/u. A new electronic device has been developed at GANIL to measure phase and amplitude of pick-up signals and calculate the beam energy. The principle consists of directly digitizing the pick-up pulses by under-sampling. The Phase and amplitude of different harmonics are then calculated with a FPGA by an I/Q method before the beam energy calculation. This paper gives results of the peak-up tests in laboratory and the comparisons with simulations. The tests in laboratory and on the GANIL accelerator of an electronic prototype are shown and presented.