IBIC2015 - List of Authors (Welsch, C.P.)

Paper	Title	Page
MOPB043	A Cryogenic Current Comparator for the Low-Energy Antiproton Facilities at CERN	143
	M.F. Fernandes, J. Tan CERN, Geneva, Switzerland M.F. Fernandes, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom M.F. Fernandes, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom R. Geithner, T. Stöhlker IOQ, Jena, Germany R. Geithner, T. Stöhlker HIJ, Jena, Germany R. Neubert FSU Jena, Jena, Germany M. Schwickert, T. Stöhlker GSI, Darmstadt, Germany
	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 Cryogenic Current Comparators (CCC) for an absolute measurement of beam intensity down to the nA level. This type of current monitor relies on the use of Superconducting QUantum Interference Device (SQUID) magnetometers and superconductor magnetic shields. CERN, in collaboration with GSI Helmholtz Centre for Heavy Ion Research, Jena University, and the Helmholtz Institute Jena are currently developing an improved version of such a current monitor for the Antiproton Decelerator (AD) and Extra Low ENergy Antiproton (ELENA) rings. The primary goals are a better current measurement accuracy and overall enhanced system availability. This contribution presents the design of the CCC, an estimation of its resolution, dynamic limitations of the SQUID, as well as a description of the modifications to the coupling circuit and cryostat that were required to optimize the monitor for the anticipated beam parameters. First results from beam measurements are also presented. To our knowledge these are the first CCC beam current measurements performed in a synchrotron and the first to be performed with both coasting and bunched beams.
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MOPB045	BLM Crosstalk Studies on the CLIC Two-Beam Module	148
	M. Kastriotou, S. Döbert, F.S. Domingues Sousa, E. Effinger, W. Farabolini, E.B. Holzer, E. Nebot Del Busto, W. Viganò CERN, Geneva, Switzerland W. Farabolini CEA/DSM/IRFU, CEA/DSM/IRFU, France M. Kastriotou, E. Nebot Del Busto, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom M. Kastriotou, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	The Compact Linear Collider (CLIC) is a proposal for a future linear e⁺-e⁻ accelerator that can reach 3 TeV centre of mass energy. It is based on a two-beam acceleration scheme, with two accelerators operating in parallel. One of the main CLIC elements is a 2 m long two-beam module where power from a high intensity, low energy drive beam is extracted through Power Extraction and Transfer Structures (PETS) and transferred as RF power for the acceleration of the low intensity, high energy main beam. One of the main potential limitations for a Beam Loss Monitoring (BLM) system in a two-beam accelerator is so-called 'crosstalk', i.e. signals generated by losses in one beam, but detected by a monitor protecting the other beam. This contribution presents results from comprehensive studies into crosstalk that have been performed at a two-beam module at the CLIC Test Facility (CTF3) at CERN. The capability of estimating the origin of losses for different scenarios is also discussed.
	Poster MOPB045 [2.471 MB]
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MOPB067	Optical Diagnostics within LA3NET	211
	C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom C.P. Welsch The University of Liverpool, Liverpool, United Kingdom
	Funding: This project has received funding from the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement no 289191. The Laser Applications at Accelerators network (LA3NET) is a pan-European project that has received 4.6 MEUR of funding within the European Union's 7th Framework Programme. It closely links research into lasers and accelerators to develop advanced particle sources, new accelerating schemes, and in particular beyond state-of-the-art beam diagnostics. This contribution summarizes the research achievements in optical diagnostics of this 4 year research and training initiative. It presents the achievable resolution of a laser-based velocimeter to measure the velocity of neutral particle beams, results from the measurement of bunch shape using electro-optical crystals with tens of fs resolution, experimental data using a laser wire scanner, and discusses the resolution limits in energy measurements using Compton backscattering at a synchrotron light source. Finally, it also provides a summary of events that have been organized by the LA3NET consortium.
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MOPB068	Advanced Beam Diagnostics R&D within oPAC	216
	C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom C.P. Welsch The University of Liverpool, Liverpool, United Kingdom
	Funding: This project has received funding from the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement no 289485. oPAC 'Optimization of Particle Accelerators' is a European research and training network that has received funding by the EU within the 7th Framework Programme. With a total budget of 6 M' and 23 Fellows that are employed within the project, it is the largest Marie Curie network to date. oPAC was started in 2011 and will come to an end at the end of 2015. It currently joins more than 30 partner institutions from all around the world, including research centres, universities and the private sector. One of the projects largest work packages addresses advanced R&D in beam diagnostics. This includes studies into advanced instrumentation for synchrotron light sources and medical accelerators, enhanced beam loss monitoring technologies, ultra-low emittance beam size diagnostics, beam diagnostics for high intensity beams, as well as the development of compact electronics for beam position monitors. This contribution will present the research outcomes of this work package and discuss the demonstrated performance of each diagnostic. A summary of the various events the network has organized for the accelerator community will also be given.
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TUPB070	Beam Characterization Using Laser Self-Mixing	516
	A.S. Alexandrova, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom A.S. Alexandrova, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: The European Union's Seventh Framework Programme under grant agreement no 289191; HGF and GSI under contract VH-NG-328 and STFC under the Cockcroft Institute Core Grant No.ST/G008248/1 Non-destructive diagnostics of particle beams is highly desirable for essentially any accelerator or storage ring. This concerns the characterization of the primary beam itself, but also for example of atom and molecular jets that are crossed with the primary beam as experimental targets or for diagnostics purposes. A laser-feedback interferometer based on the optical self-mixing effect provides a low-cost, robust, compact and non-invasive sensor for velocity, displacement and density measurements of various targets. This contribution presents results from theoretical and experimental studies into the factors influencing the performance and accuracy of this sensor. Parameters that have been assessed include the target velocity, the size of scattering particles, their density, type and scattering properties.
	Poster TUPB070 [3.390 MB]
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TUPB075	Development of a Supersonic Gas Jet Beam Profile Monitor	530
	H.D. Zhang, A. Jeff, V. Tzoganis, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom A. Jeff CERN, Geneva, Switzerland A. Jeff, V. Tzoganis, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom V. Tzoganis RIKEN, Saitama, Japan V. Tzoganis RIKEN Nishina Center, Wako, Japan
	A supersonic gas jet beam profile monitor has been developed by the QUASAR Group at the Cockcroft Institute, UK. It creates a supersonic gas curtain which interacts with the primary beam, and then images the beam cross-section by collecting the generated ions. The gas curtain is inclined at 45 degrees to the beam and functions as a minimally intercepting screen, which allows it to be used in high energy and high power beams without worrying about material damage. An accurate profile measurement requires homogeneous gas density across the curtain, while high resolution measurement requires a very thin jet. In order to characterize the gas curtain density distribution and understand the jet better, a new movable gauge module has been installed in the gas jet test stand. In this contribution, we discuss the monitor design and the characterization of the gas curtain with the newly installed movable gauge module. In addition, we present a new method for the generation of a very narrow pencil jet using deBroglie wave focusing. Such a narrow jet could be used as a non-invasive counterpart to wire scanners in high-intensity beams where the latter cannot be used.
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WEBLA03	Position Resolution of Optical Fibre-Based Beam Loss Monitors Using Long Electron Pulses	580
	E. Nebot Del Busto, S. Döbert, F.S. Domingues Sousa, E. Effinger, W. Farabolini, E.B. Holzer, M. Kastriotou, W. Viganò CERN, Geneva, Switzerland M.J. Boland ASCo, Clayton, Victoria, Australia M.J. Boland SLSA, Clayton, Australia M.J. Boland, R.P. Rassool The University of Melbourne, Melbourne, Victoria, Australia W. Farabolini CEA/DSM/IRFU, France M. Kastriotou, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom M. Kastriotou, E. Nebot Del Busto, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom
	Beam loss monitoring systems based on optical fibres (oBLM), have been under consideration for future colliders for several years. To distinguish losses between consecutive quadrupoles, a position resolution of less than 1 m is required. A resolution of better than 0.5 m has been achieved in machines with single, nanosecond long pulses. For longer beam pulses, such as the ~150 ns CLIC pulse, the longitudinal length of signals in the fibre is close to the duration of the beam pulse itself which makes loss reconstruction very challenging. In this contribution, results from experiments into the position resolution of an oBLM based on long beam pulses are presented. These measurements have been performed at the CLIC Test Facility (CTF3) and the Australian Synchrotron Light Source (ASLS). In CTF3, controlled beam losses were created at different quadrupoles in the 28 m long decelerating Test Beam Line (TBL) LINAC by altering the current supplied or misaligning them. In ASLS the flexibility of the facility allowed the location of beam losses generated by single bunches to be studied as well as losses for longer bunch trains up to 600 ns in duration.
	Slides WEBLA03 [2.109 MB]
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Paper

Title

Page

A Cryogenic Current Comparator for the Low-Energy Antiproton Facilities at CERN

143

M.F. Fernandes, J. Tan
CERN, Geneva, Switzerland
M.F. Fernandes, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
M.F. Fernandes, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
R. Geithner, T. Stöhlker
IOQ, Jena, Germany
R. Geithner, T. Stöhlker
HIJ, Jena, Germany
R. Neubert
FSU Jena, Jena, Germany
M. Schwickert, T. Stöhlker
GSI, Darmstadt, Germany

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 Cryogenic Current Comparators (CCC) for an absolute measurement of beam intensity down to the nA level. This type of current monitor relies on the use of Superconducting QUantum Interference Device (SQUID) magnetometers and superconductor magnetic shields. CERN, in collaboration with GSI Helmholtz Centre for Heavy Ion Research, Jena University, and the Helmholtz Institute Jena are currently developing an improved version of such a current monitor for the Antiproton Decelerator (AD) and Extra Low ENergy Antiproton (ELENA) rings. The primary goals are a better current measurement accuracy and overall enhanced system availability. This contribution presents the design of the CCC, an estimation of its resolution, dynamic limitations of the SQUID, as well as a description of the modifications to the coupling circuit and cryostat that were required to optimize the monitor for the anticipated beam parameters. First results from beam measurements are also presented. To our knowledge these are the first CCC beam current measurements performed in a synchrotron and the first to be performed with both coasting and bunched beams.

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MOPB045

BLM Crosstalk Studies on the CLIC Two-Beam Module

148

M. Kastriotou, S. Döbert, F.S. Domingues Sousa, E. Effinger, W. Farabolini, E.B. Holzer, E. Nebot Del Busto, W. Viganò
CERN, Geneva, Switzerland
W. Farabolini
CEA/DSM/IRFU, CEA/DSM/IRFU, France
M. Kastriotou, E. Nebot Del Busto, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
M. Kastriotou, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

The Compact Linear Collider (CLIC) is a proposal for a future linear e⁺-e⁻ accelerator that can reach 3 TeV centre of mass energy. It is based on a two-beam acceleration scheme, with two accelerators operating in parallel. One of the main CLIC elements is a 2 m long two-beam module where power from a high intensity, low energy drive beam is extracted through Power Extraction and Transfer Structures (PETS) and transferred as RF power for the acceleration of the low intensity, high energy main beam. One of the main potential limitations for a Beam Loss Monitoring (BLM) system in a two-beam accelerator is so-called 'crosstalk', i.e. signals generated by losses in one beam, but detected by a monitor protecting the other beam. This contribution presents results from comprehensive studies into crosstalk that have been performed at a two-beam module at the CLIC Test Facility (CTF3) at CERN. The capability of estimating the origin of losses for different scenarios is also discussed.

Poster MOPB045 [2.471 MB]

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MOPB067

Optical Diagnostics within LA3NET

211

C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom

Funding: This project has received funding from the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement no 289191.
The Laser Applications at Accelerators network (LA3NET) is a pan-European project that has received 4.6 MEUR of funding within the European Union's 7th Framework Programme. It closely links research into lasers and accelerators to develop advanced particle sources, new accelerating schemes, and in particular beyond state-of-the-art beam diagnostics. This contribution summarizes the research achievements in optical diagnostics of this 4 year research and training initiative. It presents the achievable resolution of a laser-based velocimeter to measure the velocity of neutral particle beams, results from the measurement of bunch shape using electro-optical crystals with tens of fs resolution, experimental data using a laser wire scanner, and discusses the resolution limits in energy measurements using Compton backscattering at a synchrotron light source. Finally, it also provides a summary of events that have been organized by the LA3NET consortium.

Export •

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

MOPB068

Advanced Beam Diagnostics R&D within oPAC

216

C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom

Funding: This project has received funding from the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement no 289485.
oPAC 'Optimization of Particle Accelerators' is a European research and training network that has received funding by the EU within the 7th Framework Programme. With a total budget of 6 M' and 23 Fellows that are employed within the project, it is the largest Marie Curie network to date. oPAC was started in 2011 and will come to an end at the end of 2015. It currently joins more than 30 partner institutions from all around the world, including research centres, universities and the private sector. One of the projects largest work packages addresses advanced R&D in beam diagnostics. This includes studies into advanced instrumentation for synchrotron light sources and medical accelerators, enhanced beam loss monitoring technologies, ultra-low emittance beam size diagnostics, beam diagnostics for high intensity beams, as well as the development of compact electronics for beam position monitors. This contribution will present the research outcomes of this work package and discuss the demonstrated performance of each diagnostic. A summary of the various events the network has organized for the accelerator community will also be given.

Export •

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

TUPB070

Beam Characterization Using Laser Self-Mixing

516

A.S. Alexandrova, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
A.S. Alexandrova, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: The European Union's Seventh Framework Programme under grant agreement no 289191; HGF and GSI under contract VH-NG-328 and STFC under the Cockcroft Institute Core Grant No.ST/G008248/1
Non-destructive diagnostics of particle beams is highly desirable for essentially any accelerator or storage ring. This concerns the characterization of the primary beam itself, but also for example of atom and molecular jets that are crossed with the primary beam as experimental targets or for diagnostics purposes. A laser-feedback interferometer based on the optical self-mixing effect provides a low-cost, robust, compact and non-invasive sensor for velocity, displacement and density measurements of various targets. This contribution presents results from theoretical and experimental studies into the factors influencing the performance and accuracy of this sensor. Parameters that have been assessed include the target velocity, the size of scattering particles, their density, type and scattering properties.

Poster TUPB070 [3.390 MB]

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TUPB075

Development of a Supersonic Gas Jet Beam Profile Monitor

530

H.D. Zhang, A. Jeff, V. Tzoganis, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
A. Jeff
CERN, Geneva, Switzerland
A. Jeff, V. Tzoganis, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
V. Tzoganis
RIKEN, Saitama, Japan
V. Tzoganis
RIKEN Nishina Center, Wako, Japan

A supersonic gas jet beam profile monitor has been developed by the QUASAR Group at the Cockcroft Institute, UK. It creates a supersonic gas curtain which interacts with the primary beam, and then images the beam cross-section by collecting the generated ions. The gas curtain is inclined at 45 degrees to the beam and functions as a minimally intercepting screen, which allows it to be used in high energy and high power beams without worrying about material damage. An accurate profile measurement requires homogeneous gas density across the curtain, while high resolution measurement requires a very thin jet. In order to characterize the gas curtain density distribution and understand the jet better, a new movable gauge module has been installed in the gas jet test stand. In this contribution, we discuss the monitor design and the characterization of the gas curtain with the newly installed movable gauge module. In addition, we present a new method for the generation of a very narrow pencil jet using deBroglie wave focusing. Such a narrow jet could be used as a non-invasive counterpart to wire scanners in high-intensity beams where the latter cannot be used.

Export •

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

WEBLA03

Position Resolution of Optical Fibre-Based Beam Loss Monitors Using Long Electron Pulses

580

E. Nebot Del Busto, S. Döbert, F.S. Domingues Sousa, E. Effinger, W. Farabolini, E.B. Holzer, M. Kastriotou, W. Viganò
CERN, Geneva, Switzerland
M.J. Boland
ASCo, Clayton, Victoria, Australia
M.J. Boland
SLSA, Clayton, Australia
M.J. Boland, R.P. Rassool
The University of Melbourne, Melbourne, Victoria, Australia
W. Farabolini
CEA/DSM/IRFU, France
M. Kastriotou, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
M. Kastriotou, E. Nebot Del Busto, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom

Beam loss monitoring systems based on optical fibres (oBLM), have been under consideration for future colliders for several years. To distinguish losses between consecutive quadrupoles, a position resolution of less than 1 m is required. A resolution of better than 0.5 m has been achieved in machines with single, nanosecond long pulses. For longer beam pulses, such as the ~150 ns CLIC pulse, the longitudinal length of signals in the fibre is close to the duration of the beam pulse itself which makes loss reconstruction very challenging. In this contribution, results from experiments into the position resolution of an oBLM based on long beam pulses are presented. These measurements have been performed at the CLIC Test Facility (CTF3) and the Australian Synchrotron Light Source (ASLS). In CTF3, controlled beam losses were created at different quadrupoles in the 28 m long decelerating Test Beam Line (TBL) LINAC by altering the current supplied or misaligning them. In ASLS the flexibility of the facility allowed the location of beam losses generated by single bunches to be studied as well as losses for longer bunch trains up to 600 ns in duration.

Slides WEBLA03 [2.109 MB]

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