IBIC2014 - Classification: Beam Charge Monitors

Paper	Title	Page
WECZB1	A SQUID-Based Beam Current Monitor for FAIR/CRYRING	510
	R. Geithner, T. Stöhlker IOQ, Jena, Germany R. Geithner, T. Stöhlker HIJ, Jena, Germany F. Kurian, H. Reeg, M. Schwickert, T. Stöhlker GSI, Darmstadt, Germany R. Neubert, P. Seidel FSU Jena, Jena, Germany
	A SQUID-based beam current monitor was developed for the upcoming FAIR-Project, providing a non-destructive online monitoring of the beam currents in the nA-range. The Cryogenic Current Comparator (CCC) was optimized for a lowest possible noise-limited current resolution together with a high system bandwidth. This CCC should be installed in the CRYRING facility, working as a test bench for FAIR. In this contribution we present results of the completed CCC for FAIR/CRYRING and also arrangements that have been done for the installation of the CCC at CRYRING, regarding the cryostat design.
	Slides WECZB1 [6.109 MB]
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WEPF02	A Toroid Based Bunch Charge Monitor System with Machine Protection Features for FLASH and XFEL	521
	M. Werner, T. Lensch, J. Lund-Nielsen, Re. Neumann, D. Nölle, N. Wentowski DESY, Hamburg, Germany
	For the superconducting linear accelerators FLASH and XFEL, a new toroid based charge measurement system has been designed as a standard diagnostic tool. It is also a sensor for the bunch charge stabilization feedback and for machine protection. The system is based on MTCA.4 technology and will offer a high dynamic range and high sensitivity. The machine protection features will cover recognition of poor transmission between adjacent toroid sensors, bunch pattern consistency checks, and protection of the beam dumps. The concept, an overview of the algorithms, and the implementation will be described. A summary of first operation experience at FLASH will be presented.
	Poster WEPF02 [1.113 MB]
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WEPF03	Upgrade of the Fast Beam Intensity Measurement System for the CERN PS Complex	525
	D. Belohrad, J.C.A. Allica, M. Andersen, W. Andreazza, G. Favre, N. Favre, L.K. Jensen, L. Lenardon, W. Vollenberg CERN, Geneva, Switzerland
	The CERN Proton Synchrotron complex (CPS) has been operational for over 50 years. During this time the Fast Beam Current Transformers (FBCTs) have only been repaired when they ceased to function, or individually modified to cope with new requests. This strategy resulted in a large variation of designs, making their maintenance difficult and limiting the precision with which comparisons could be made between transformers for the measurement of beam intensity transmission. During the first long shut-down of the CERN LHC and its injectors (LS1) these systems have undergone a major consolidation, with detectors and acquisition electronics upgraded to provide a uniform measurement system throughout the PS complex. This paper discusses the solutions used and analyses the first beam measurement results.
	Poster WEPF03 [7.547 MB]
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WEPF04	A Cryogenic Current Comparator for the Low Energy Antiproton Facitities at CERN	530
	M.F. Fernandes, J. Tan CERN, Geneva, Switzerland C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom C.P. Welsch The University of Liverpool, Liverpool, United Kingdom
	Funding: Funded by the European Unions Seventh Framework Programme for research, technological development and demonstration under grant agreement no 289485. Several laboratories have shown the potential of using Superconducting QUantum Interference Device (SQUID) magnetometers together with superconductor magnetic shields to measure beam current intensities in the sub-micro-Ampere regime. CERN, in collaboration with GSI, Jena university and Helmholtz Institute Jena, is currently working on developing an improved version of such a current monitor for the Antiproton Decelerator (AD) and Extra Low ENergy Antiproton (ELENA) rings at CERN, aiming for better current resolution and overall system availability. This contribution will present the current design, including theoretical estimation of the current resolution; stability limits of SQUID systems and adaptation of the coupling circuit to the AD beam parameters; the analysis of thermal and mechanical cryostat modes.
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WEPF05	Simulation of the Beam Dump for a High Intensity Electron Gun	536
	A. Jeff, S. Döbert, T. Lefèvre CERN, Geneva, Switzerland A. Jeff The University of Liverpool, Liverpool, United Kingdom K. Pepitone CEA, LE BARP cedex, France
	The CLIC Drive Beam is a high-intensity pulsed electron beam. A test facility for the Drive Beam electron gun will soon be commissioned at CERN. In this contribution we outline the design of a beam dump / Faraday cup capable of resisting the beam’s thermal load. The test facility will operate initially up to 140 keV. At such low energies, the electrons are absorbed very close to the surface of the dump, leading to a large energy deposition density in this thin layer. In order not to damage the dump, the beam must be spread over a large surface. For this reason, a small-angled cone has been chosen. Simulations using geant4 have been performed to estimate the distribution of energy deposition in the dump. The heat transport both within the electron pulse and between pulses has been modelled using finite element methods to check the resistance of the dump at high repetition rates. In addition, the possibility of using a moveable dump to measure the beam profile and emittance is discussed.
	Poster WEPF05 [0.224 MB]
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WEPF06	A New Integrating Current Transformer for the LHC	540
	L. Søby, D. Belohrad, M. Krupa, P. Odier CERN, Geneva, Switzerland J.F. Bergoz, F. Stulle BERGOZ Instrumentation, Saint Genis Pouilly, France
	The existing fast beam current transformers of the LHC have been shown to exhibit both bunch length and bunch position dependency. A new Integrating Current Transformer (ICT) have therefore been developed in collaboration with Bergoz Instrumentation to address these issues. As goals a 0.1 %/mm beam position dependency and 0.1 % bunch length dependency were specified, along with a bandwidth of 100 MHz. This paper describes the principles of ICT operation and presents the laboratory measurement results obtained with the first prototypes at CERN.
	Poster WEPF06 [2.286 MB]
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WEPF07	Optimization of a Short Faraday Cup for Low-Energy Ions Using Numerical Simulations	544
	A.G. Sosa, E. Bravin, E.D. Cantero CERN, Geneva, Switzerland C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom C.P. Welsch The University of Liverpool, Liverpool, United Kingdom
	Funding: CATHI is a Marie Curie Initial Training Network funded by the European Commission under Grant Agreement Number PITN-GA-2010-264330. ISOLDE, the heavy-ion facility at CERN is undergoing a major upgrade with the installation of a superconducting LINAC that will allow post-acceleration of ion beams up to 10 MeV/u. In this framework, customized beam diagnostics are being developed in order to fulfill the design requirements as well as to fit in the compact diagnostic boxes foreseen. The main detector of this system is a compact Faraday cup that will measure beam intensities in the range of 1 pA to 1 nA. In this contribution, simulation results of electrostatic fields and particle tracking are detailed for different Faraday cup prototypes taking into account the energy spectrum and angle of emission of the ion-induced secondary electrons.
	Poster WEPF07 [1.282 MB]
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WEPF08	Dosimetry of Pulsed Beams in Proton Therapy	548
	J. van de Walle, Y. Claereboudt, G. Krier, D. Prieels IBA, Louvain-la-Neuve, Belgium G. Boissonnat, J. Colin, J.-M. Fontbonne LPC, Caen, France
	Ion Beam Applications (IBA) has developed in recent years the ProteusONE proton therapy system, which aims at reducing the cost and footprint of proton therapy systems, making them affordable and accessible to more patients worldwide. The heart of the ProteusONE system is a super conducting synchro-cyclotron (S2C2), which provides short (10 μs) proton bunches at 1 kHz. This is in contrast to the proton therapy systems including the IBA Cyclone230, which delivers a continuous beam. Nevertheless, the same average dose rates are provided by both systems. As a consequence, the instantaneous dose rates with the S2C2 are much higher and recombination losses in the large area beam diagnostics and dosimetry devices become non negligible. Since the proton charge which is send to a patient should be measured with high precision, these recombination losses have to be addressed carefully. In this work, a large area (30x30 cm²) and large gap (>3 mm) ionization chamber (IC) is presented which allows to quantify recombination losses in each beam pulse on-line. The principle is based on the introduction of two ionization volumes in series with slightly different gap sizes. The ratio of detected charges in both IC's is the basic observable which is used to recalculate the efficiency of each IC. The principle of this so-called "asymmetric ionization chamber" (AIC) was tested with beam from the S2C2 prototype. The results show that the efficiency can be re-calculated to 0.5% precision for voltages higher than 1000 V. Together with the experimental results, the theoretical background of the recombination losses will be discussed and it will be shown how this theory is applied in a robust and simple way to correct for these losses in the proton therapy system.
	Poster WEPF08 [0.999 MB]
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WEPF09	Introduction to the Test Result of Turbo-ICT in PAL-ITF	553
	H. J. Choi, M.S. Chae, H.-S. Kang, S.J. Park PAL, Pohang, Kyungbuk, Republic of Korea
	Pohang Accelerator Laboratory (PAL) built a PAL-ITF (Injector Test Facility) at the end of 2012 to successfully complete PAL-XFEL (X-ray Free Electron Laser) in 2015. The PAL-ITF is equipped with various kinds of diagnostic equipment to produce high-quality electron bunches. The three main parameters that an injection testing facility should measure are charge, energy and emittance. Although ICT and Faraday Cup were installed to measure beam charge, the noise generated in a klystron modulator not only interrupted accurate measurement but prevented low charges under tens of pC from being measured. Due to the changes in the overall voltage level of ITF, integration of ICT measured value failed to maintain perfect accuracy in terms of methodology (measured value continuously changed by ± 5pC). Accordingly, to solve the noise problems and accurately measure the quantity of electron beam charge, Turbo-ICT was installed. This paper focuses on the processes and test result of electric bunch charge quantity measurements using Turbo-ICT.
	Poster WEPF09 [2.807 MB]
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Paper

Title

Page

A SQUID-Based Beam Current Monitor for FAIR/CRYRING

510

R. Geithner, T. Stöhlker
IOQ, Jena, Germany
R. Geithner, T. Stöhlker
HIJ, Jena, Germany
F. Kurian, H. Reeg, M. Schwickert, T. Stöhlker
GSI, Darmstadt, Germany
R. Neubert, P. Seidel
FSU Jena, Jena, Germany

A SQUID-based beam current monitor was developed for the upcoming FAIR-Project, providing a non-destructive online monitoring of the beam currents in the nA-range. The Cryogenic Current Comparator (CCC) was optimized for a lowest possible noise-limited current resolution together with a high system bandwidth. This CCC should be installed in the CRYRING facility, working as a test bench for FAIR. In this contribution we present results of the completed CCC for FAIR/CRYRING and also arrangements that have been done for the installation of the CCC at CRYRING, regarding the cryostat design.

Slides WECZB1 [6.109 MB]

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reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

WEPF02

A Toroid Based Bunch Charge Monitor System with Machine Protection Features for FLASH and XFEL

521

M. Werner, T. Lensch, J. Lund-Nielsen, Re. Neumann, D. Nölle, N. Wentowski
DESY, Hamburg, Germany

For the superconducting linear accelerators FLASH and XFEL, a new toroid based charge measurement system has been designed as a standard diagnostic tool. It is also a sensor for the bunch charge stabilization feedback and for machine protection. The system is based on MTCA.4 technology and will offer a high dynamic range and high sensitivity. The machine protection features will cover recognition of poor transmission between adjacent toroid sensors, bunch pattern consistency checks, and protection of the beam dumps. The concept, an overview of the algorithms, and the implementation will be described. A summary of first operation experience at FLASH will be presented.

Poster WEPF02 [1.113 MB]

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reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

WEPF03

Upgrade of the Fast Beam Intensity Measurement System for the CERN PS Complex

525

D. Belohrad, J.C.A. Allica, M. Andersen, W. Andreazza, G. Favre, N. Favre, L.K. Jensen, L. Lenardon, W. Vollenberg
CERN, Geneva, Switzerland

The CERN Proton Synchrotron complex (CPS) has been operational for over 50 years. During this time the Fast Beam Current Transformers (FBCTs) have only been repaired when they ceased to function, or individually modified to cope with new requests. This strategy resulted in a large variation of designs, making their maintenance difficult and limiting the precision with which comparisons could be made between transformers for the measurement of beam intensity transmission. During the first long shut-down of the CERN LHC and its injectors (LS1) these systems have undergone a major consolidation, with detectors and acquisition electronics upgraded to provide a uniform measurement system throughout the PS complex. This paper discusses the solutions used and analyses the first beam measurement results.

Poster WEPF03 [7.547 MB]

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WEPF04

A Cryogenic Current Comparator for the Low Energy Antiproton Facitities at CERN

530

M.F. Fernandes, J. Tan
CERN, Geneva, Switzerland
C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom

Funding: Funded by the European Unions Seventh Framework Programme for research, technological development and demonstration under grant agreement no 289485.
Several laboratories have shown the potential of using Superconducting QUantum Interference Device (SQUID) magnetometers together with superconductor magnetic shields to measure beam current intensities in the sub-micro-Ampere regime. CERN, in collaboration with GSI, Jena university and Helmholtz Institute Jena, is currently working on developing an improved version of such a current monitor for the Antiproton Decelerator (AD) and Extra Low ENergy Antiproton (ELENA) rings at CERN, aiming for better current resolution and overall system availability. This contribution will present the current design, including theoretical estimation of the current resolution; stability limits of SQUID systems and adaptation of the coupling circuit to the AD beam parameters; the analysis of thermal and mechanical cryostat modes.

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

WEPF05

Simulation of the Beam Dump for a High Intensity Electron Gun

536

A. Jeff, S. Döbert, T. Lefèvre
CERN, Geneva, Switzerland
A. Jeff
The University of Liverpool, Liverpool, United Kingdom
K. Pepitone
CEA, LE BARP cedex, France

The CLIC Drive Beam is a high-intensity pulsed electron beam. A test facility for the Drive Beam electron gun will soon be commissioned at CERN. In this contribution we outline the design of a beam dump / Faraday cup capable of resisting the beam’s thermal load. The test facility will operate initially up to 140 keV. At such low energies, the electrons are absorbed very close to the surface of the dump, leading to a large energy deposition density in this thin layer. In order not to damage the dump, the beam must be spread over a large surface. For this reason, a small-angled cone has been chosen. Simulations using geant4 have been performed to estimate the distribution of energy deposition in the dump. The heat transport both within the electron pulse and between pulses has been modelled using finite element methods to check the resistance of the dump at high repetition rates. In addition, the possibility of using a moveable dump to measure the beam profile and emittance is discussed.

Poster WEPF05 [0.224 MB]

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WEPF06

A New Integrating Current Transformer for the LHC

540

L. Søby, D. Belohrad, M. Krupa, P. Odier
CERN, Geneva, Switzerland
J.F. Bergoz, F. Stulle
BERGOZ Instrumentation, Saint Genis Pouilly, France

The existing fast beam current transformers of the LHC have been shown to exhibit both bunch length and bunch position dependency. A new Integrating Current Transformer (ICT) have therefore been developed in collaboration with Bergoz Instrumentation to address these issues. As goals a 0.1 %/mm beam position dependency and 0.1 % bunch length dependency were specified, along with a bandwidth of 100 MHz. This paper describes the principles of ICT operation and presents the laboratory measurement results obtained with the first prototypes at CERN.

Poster WEPF06 [2.286 MB]

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reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

WEPF07

Optimization of a Short Faraday Cup for Low-Energy Ions Using Numerical Simulations

544

A.G. Sosa, E. Bravin, E.D. Cantero
CERN, Geneva, Switzerland
C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom

Funding: CATHI is a Marie Curie Initial Training Network funded by the European Commission under Grant Agreement Number PITN-GA-2010-264330.
ISOLDE, the heavy-ion facility at CERN is undergoing a major upgrade with the installation of a superconducting LINAC that will allow post-acceleration of ion beams up to 10 MeV/u. In this framework, customized beam diagnostics are being developed in order to fulfill the design requirements as well as to fit in the compact diagnostic boxes foreseen. The main detector of this system is a compact Faraday cup that will measure beam intensities in the range of 1 pA to 1 nA. In this contribution, simulation results of electrostatic fields and particle tracking are detailed for different Faraday cup prototypes taking into account the energy spectrum and angle of emission of the ion-induced secondary electrons.

Poster WEPF07 [1.282 MB]

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reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

WEPF08

Dosimetry of Pulsed Beams in Proton Therapy

548

J. van de Walle, Y. Claereboudt, G. Krier, D. Prieels
IBA, Louvain-la-Neuve, Belgium
G. Boissonnat, J. Colin, J.-M. Fontbonne
LPC, Caen, France

Ion Beam Applications (IBA) has developed in recent years the ProteusONE proton therapy system, which aims at reducing the cost and footprint of proton therapy systems, making them affordable and accessible to more patients worldwide. The heart of the ProteusONE system is a super conducting synchro-cyclotron (S2C2), which provides short (10 μs) proton bunches at 1 kHz. This is in contrast to the proton therapy systems including the IBA Cyclone230, which delivers a continuous beam. Nevertheless, the same average dose rates are provided by both systems. As a consequence, the instantaneous dose rates with the S2C2 are much higher and recombination losses in the large area beam diagnostics and dosimetry devices become non negligible. Since the proton charge which is send to a patient should be measured with high precision, these recombination losses have to be addressed carefully. In this work, a large area (30x30 cm²) and large gap (>3 mm) ionization chamber (IC) is presented which allows to quantify recombination losses in each beam pulse on-line. The principle is based on the introduction of two ionization volumes in series with slightly different gap sizes. The ratio of detected charges in both IC's is the basic observable which is used to recalculate the efficiency of each IC. The principle of this so-called "asymmetric ionization chamber" (AIC) was tested with beam from the S2C2 prototype. The results show that the efficiency can be re-calculated to 0.5% precision for voltages higher than 1000 V. Together with the experimental results, the theoretical background of the recombination losses will be discussed and it will be shown how this theory is applied in a robust and simple way to correct for these losses in the proton therapy system.

Poster WEPF08 [0.999 MB]

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reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

WEPF09

Introduction to the Test Result of Turbo-ICT in PAL-ITF

553

H. J. Choi, M.S. Chae, H.-S. Kang, S.J. Park
PAL, Pohang, Kyungbuk, Republic of Korea

Pohang Accelerator Laboratory (PAL) built a PAL-ITF (Injector Test Facility) at the end of 2012 to successfully complete PAL-XFEL (X-ray Free Electron Laser) in 2015. The PAL-ITF is equipped with various kinds of diagnostic equipment to produce high-quality electron bunches. The three main parameters that an injection testing facility should measure are charge, energy and emittance. Although ICT and Faraday Cup were installed to measure beam charge, the noise generated in a klystron modulator not only interrupted accurate measurement but prevented low charges under tens of pC from being measured. Due to the changes in the overall voltage level of ITF, integration of ICT measured value failed to maintain perfect accuracy in terms of methodology (measured value continuously changed by ± 5pC). Accordingly, to solve the noise problems and accurately measure the quantity of electron beam charge, Turbo-ICT was installed. This paper focuses on the processes and test result of electric bunch charge quantity measurements using Turbo-ICT.

Poster WEPF09 [2.807 MB]

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