IBIC2013 - List of Keywords (CLIC)

Paper	Title	Other Keywords	Page
MOCL3	Emittance and Momentum Diagnostics for Beams with Large Momentum Spread	quadrupole, emittance, diagnostics, transverse	37
	M. Olvegård, V.G. Ziemann Uppsala University, Uppsala, Sweden
	In the drive beam complex of CLIC, but also in plasma wakefield accelerators, the momentum spread can be on the order of tens of percent while conventional diagnostic methods often assume a very small momentum spread. This leads to systematic misinterpretations of the measurements. Spectrometry and emittance measurements based on quadrupole scan rely on measuring the beam size, which depends on the beam envelope. This, in turn, depends on the momentum distribution. We have studied the systematic errors that arise and developed novel algorithms to correctly analyze these measurements for arbitrary momentum distributions. As an application we consider the CLIC drive beam decelerator, where extraction of up to 90% of the kinetic energy leads to a very large momentum spread. We study a measurement of the time-resolved momentum distribution, based on sweeping the beam in a circular pattern and recording the beam size on a screen using optical transition radiation. We present the algorithm to extract the time-resolved momentum distribution, together with simulation results to prove its applicability.
	Slides MOCL3 [2.984 MB]

MOPC47	Monte Carlo Simulations of Beam Losses in the Test Beam Line of CTF3	beam-losses, quadrupole, electron, simulation	189
	E. Nebot Del Busto, S. Mallows, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom E. Branger Linköping University, Linköping, Sweden S. Döbert, E.B. Holzer, R.L. Lillestøl, S. Mallows, E. Nebot Del Busto CERN, Geneva, Switzerland R.L. Lillestøl University of Oslo, Oslo, Norway C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	The Test Beam Line (TBL) of the CLIC Test Facility 3 (CTF3) aims to validate the drive beam deceleration concept of CLIC, in which the RF power requested to boost particles to multi-TeV energies is obtained via deceleration of a high current and low energy drive beam (DB). Despite a TBL beam energy (150-80 MeV) significantly lower than the minimum nominal energy of the CLIC DB (250 MeV), the pulse time structure of the TBL provides the opportunity to measure beam losses with CLIC-like DB timing conditions. In this contribution, a simulation study on the detection of beam losses along the TBL for the commissioning of the recently installed beam loss monitoring system is presented. The most likely loss locations during stable beam conditions are studied by considering the beam envelope defined by the FODO lattice as well as the emittance growth due to the deceleration process. Moreover, the optimization of potential detector locations is discussed. Several factors are considered, namely: the distance to the beam, the shielding provided by the different elements of the line, the detector sensitivity and possible saturation effects of both the radiation detectors and electronics.

MOPF09	A Gas-Jet Profile Monitor for the CLIC Drive Beam	electron, ion, space-charge, focusing	224
	A. Jeff, E.B. Holzer, T. Lefèvre CERN, Geneva, Switzerland A. Jeff, V. Tzoganis, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom V. Tzoganis, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	The Compact LInear Collider (CLIC) will use a novel acceleration scheme in which energy extracted from a very intense beam of relatively low-energy electrons (the Drive Beam) is used to accelerate a lower intensity Main Beam to very high energy. The high intensity of the Drive Beam, with pulses of more than 10¹⁵ electrons, poses a challenge for conventional profile measurements such as wire scanners. Thus, new non-invasive profile measurements are being investigated. Profile monitors using gas ionisation or fluorescence have been used at a number of accelerators. Typically, extra gas must be injected at the monitor and the rise in pressure spreads some distance down the beampipe. In contrast, a gas jet can be fired across the beam into a receiving chamber, with little gas escaping into the rest of the beam pipe. In addition, a gas jet shaped into a thin plane can be used like a screen on which the beam cross-section is imaged. In this paper we present some arrangements for the generation of such a jet. In addition to jet shaping using nozzles and skimmers, we propose a new scheme to use matter-wave interference with a Fresnel Zone Plate to bring an atomic jet to a narrow focus.

MOPF10	Off-Axis Undulator Radiation for CLIC Drive Beam Diagnostics	undulator, radiation, electron, transverse	228
	A. Jeff, T. Lefèvre CERN, Geneva, Switzerland A. Jeff, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom A. Jeff, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom
	The Compact LInear Collider (CLIC) will use a novel acceleration scheme in which energy extracted from a very intense beam of relatively low-energy electrons (the Drive Beam) is used to accelerate a lower intensity Main Beam to very high energy. The high intensity of the Drive Beam, with pulses of more than 10¹⁵ electrons, poses a challenge for conventional profile measurements such as wire scanners. Thus, new non-invasive profile measurements are being investigated. In this paper we propose the use of relatively inexpensive permanent-magnet undulators to generate off-axis visible Synchrotron Radiation from the CLIC Drive Beam. The field strength and period length of the undulator should be designed such that the on-axis undulator wavelength is in the ultra-violet. A smaller but still useable amount of visible light is then generated in a hollow cone. This light can be reflected out of the beam pipe by a ring-shaped mirror placed downstream and imaged on a camera. In this contribution, results of SRW and ZEMAX simulations using the CLIC Drive Beam parameters are shown.

MOPF30	Novel Diagnostics for Breakdown Studies	electron, simulation, klystron, diagnostics	287
	M. Jacewicz, Ch. Borgmann, M. Olvegård, R.J.M.Y. Ruber, V.G. Ziemann Uppsala University, Uppsala, Sweden J.W. Kovermann CERN, Geneva, Switzerland
	The phenomenon that currently prevents achieving high accelerating gradients in high energy accelerators such as the CLIC linear collider is electrical breakdown at very high electrical field. The ongoing experimental work is trying to benchmark the theoretical models focusing on the physics of vacuum breakdown which is responsible for the discharges. The CLIC collaboration has commissioned a dedicated 12 GHz test-stand to validate the feasibility of accelerating structures and observe the characteristics of the RF discharges and their eroding effects on the structure. A versatile system for detection of the dark and breakdown currents and light emission is being developed for the test-stand. It consists of a collimation system with an external magnetic spectrometer for measurement of the spatial and energy distributions of the electrons emitted from the acceleration structure during a single RF pulse. These measurements can be correlated with e.g. the location of the breakdown inside the structure using information from the incident, reflected and transmitted RF powers giving a complete picture of the vacuum breakdown phenomenon.

TUPC12	Status of the Stripline Beam Position Monitor Development for the CLIC Drive Beam	BPM, beam-position, CTF3, impedance	384
	A. Benot-Morell, L. Søby, M. Wendt CERN, Geneva, Switzerland A. Benot-Morell, A. Faus-Golfe IFIC, Valencia, Spain J.M. Nappa, S. Vilalte IN2P3-LAPP, Annecy-le-Vieux, France S.R. Smith SLAC, Menlo Park, California, USA
	Funding: MINECO contract FPA2010-21456-C02-01, SEIC-2010-00028, U.S. Department of Energy contract DE-AC02-76SF00515 In collaboration with SLAC, LAPP and IFIC, a first prototype of a strip-line Beam Position Monitor (BPM) for the CLIC Drive Beam and its associated readout electronics has been successfully tested in the CLIC Test Facility linac (CTF3) at CERN. In addition, a modified prototype with downstream terminated strip-lines is under development to better suppress any unwanted RF signal interference. This paper presents the results of the beam tests, the most relevant design aspects for the modified strip-line BPM version and its expected performance.
	Poster TUPC12 [1.729 MB]

TUPC20	Technologies and R&D for a High Resolution Cavity BPM for the CLIC Main Beam	BPM, CTF3, pick-up, coupling	415
	J.R. Towler, T. Lefèvre, L. Søby, M. Wendt CERN, Geneva, Switzerland S.T. Boogert, F.J. Cullinan, A. Lyapin JAI, Egham, Surrey, United Kingdom
	The Main Beam (MB) LINAC of the Compact Linear Collider (CLIC) requires a beam orbit measurement system with a high spatial (50 nm) and high temporal (50 ns) resolution to resolve the beam position within the 156 ns long bunch train, traveling on an energy-chirped, minimum dispersive trajectory. A 15 GHz prototype cavity BPM has been commissioned in the probe beam-line of the CTF3 CLIC Test Facility. The performance and technical details of this prototype installation are discussed in this paper, including the 15 GHz analog down-converter, the data acquisition and the control electronics and software. An R&D outlook is given for the next steps, which requires a system of 3 cavity BPMs to investigate the full resolution potential.

TUPC41	A Femtosecond Resolution Electro-Optic Diagnostic Using a Nanosecond-Pulse Laser	laser, diagnostics, alignment, longitudinal	474
	S.P. Jamison STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom W.A. Gillespie, D.A. Walsh University of Dundee, Nethergate, Dundee, Scotland, United Kingdom
	Funding: We gratefully acknowledge support under CERN collaboration agreement KE1865/TE Electro-optic longitudinal profile diagnostic systems with intrinsically improved reliability and a time resolution of 20 fs rms are being developed for CLIC. Exploiting the electro-optic effect, the bunch electric field 'pulse carves' an optical replica from a narrow bandwidth nanosecond duration laser probe. All-optical characterisation of the optical replica is via spectrally resolved auto-correlation, providing a sub-20fs resolution capability. An optical parametric amplification stage following the pulse carving, and driven by same nanosecond laser that provides the probe, enables sufficient intensity for single-shot measurement. In basing the optical system on nanosecond Q-switched lasers, bypassing complex femtosecond laser systems, the potential for robust instrumentation development is enhanced. The bandwidth limitations of the electro-optic materials are being addressed through investigations into multiple crystal detectors, and THz induced second harmonic generation on metal surfaces. Experimental results on the optical subsystems, using laser-produced THz as an electron bunch mimic, are presented together with performance projections for the integrated system.

WEAL3	Diffraction Radiation Test at CesrTA for Non-Intercepting Micron-Scale Beam Size Measurement	target, radiation, electron, CERN	619
	L.M. Bobb, E. Bravin, T. Lefèvre, S. Mazzoni CERN, Geneva, Switzerland T. Aumeyr, P. Karataev Royal Holloway, University of London, Surrey, United Kingdom M.G. Billing, J.V. Conway Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA L.M. Bobb JAI, Egham, Surrey, United Kingdom
	Diffraction radiation (DR) is produced when a relativistic charged particle moves in the vicinity of a medium. The electric field of the charged particle polarizes the target atoms which then oscillate, emitting radiation with a very broad spectrum. The spatial-spectral properties of DR are sensitive to a range of electron beam parameters. Furthermore, the energy loss due to DR is so small that the electron beam parameters are unchanged. DR can therefore be used to develop non-invasive diagnostic tools. To achieve the micron-scale resolution required to measure the transverse (vertical) beam size using incoherent DR in CLIC, DR in UV and X-ray spectral-range must be investigated. Experimental validation of such a scheme is ongoing at CesrTA at Cornell University, USA. Here we report on the test using 0.5 mm and 1 mm target apertures on a 2.1 GeV electron beam and 400 nm wavelength.
	Slides WEAL3 [2.893 MB]

WEPC43	Update on Beam Loss Monitoring at CTF3 for CLIC	DIAMOND, beam-losses, photon, quadrupole	787
	L.J. Devlin, S. Mallows, C.P. Welsch, E.N. del Busto Cockcroft Institute, Warrington, Cheshire, United Kingdom E. Branger Linköping University, Linköping, Sweden L.J. Devlin, S. Mallows, C.P. Welsch, E.N. del Busto The University of Liverpool, Liverpool, United Kingdom E. Effinger, E.B. Holzer, S. Mallows, E.N. del Busto CERN, Geneva, Switzerland
	Funding: Work supported by STFC Cockcroft Institute Core Grant No. ST/G008248/1 The primary role of the beam loss monitoring (BLM) system for the compact linear collider (CLIC) study is to work within the machine protection system. Due to the size of the CLIC facility, a BLM that covers large distances along the beamline is highly desirable, in particular for the CLIC drive beam decelerators, which would alternatively require some ~40,000 localised monitors. Therefore, an optical fiber BLM system is currently under investigation which can cover large sections of beamline at a time. A multimode fiber has been installed along the Test Beam Line at the CLIC test facility (CTF3) where the detection principle is based on the production of Cherenkov photons within the fiber resulting from beam loss and their subsequent transport along the fiber where they are then detected at the fiber ends using silicon photomultipliers. Several additional monitors including ACEMs, PEP-II and diamond detectors have also been installed. In this contribution the first results from the BLMs are presented, comparisons of the signals from each BLM are made and the possible achievable longitudinal resolution from the fiber BLM signal considering various loss patterns is discussed.

WEPC46	Beam Delivery Simulation (BDSIM): A Geant4 Based Toolkit for Diagnostics and Loss Simulation	LHC, simulation, lattice, background	799
	S.T. Boogert Royal Holloway, University of London, Surrey, United Kingdom S.T. Boogert, S.M. Gibson, R. Kwee-Hinzmann, L.J. Nevay, J. Snuverink JAI, Egham, Surrey, United Kingdom L.C. Deacon CERN, Geneva, Switzerland
	BDSIM is a Geant4 and C++ based particle tracking code which seamlessly tracks particles in accelerators and particle detectors, including the full range of particle interaction physics processes in Geant4. The code has been used to model the backgrounds in the International Linear Collider (ILC), Compact Linear Collider (CLIC), Accelerator Test Facility 2 (ATF2) and more recently the Large Hadron Collider (LHC). This paper outlines the current code and possible example applications and presents a roadmap for future developments.

Paper

Title

Other Keywords

Page

MOCL3

Emittance and Momentum Diagnostics for Beams with Large Momentum Spread

quadrupole, emittance, diagnostics, transverse

37

M. Olvegård, V.G. Ziemann
Uppsala University, Uppsala, Sweden

In the drive beam complex of CLIC, but also in plasma wakefield accelerators, the momentum spread can be on the order of tens of percent while conventional diagnostic methods often assume a very small momentum spread. This leads to systematic misinterpretations of the measurements. Spectrometry and emittance measurements based on quadrupole scan rely on measuring the beam size, which depends on the beam envelope. This, in turn, depends on the momentum distribution. We have studied the systematic errors that arise and developed novel algorithms to correctly analyze these measurements for arbitrary momentum distributions. As an application we consider the CLIC drive beam decelerator, where extraction of up to 90% of the kinetic energy leads to a very large momentum spread. We study a measurement of the time-resolved momentum distribution, based on sweeping the beam in a circular pattern and recording the beam size on a screen using optical transition radiation. We present the algorithm to extract the time-resolved momentum distribution, together with simulation results to prove its applicability.

Slides MOCL3 [2.984 MB]

MOPC47

Monte Carlo Simulations of Beam Losses in the Test Beam Line of CTF3

beam-losses, quadrupole, electron, simulation

189

E. Nebot Del Busto, S. Mallows, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
E. Branger
Linköping University, Linköping, Sweden
S. Döbert, E.B. Holzer, R.L. Lillestøl, S. Mallows, E. Nebot Del Busto
CERN, Geneva, Switzerland
R.L. Lillestøl
University of Oslo, Oslo, Norway
C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

The Test Beam Line (TBL) of the CLIC Test Facility 3 (CTF3) aims to validate the drive beam deceleration concept of CLIC, in which the RF power requested to boost particles to multi-TeV energies is obtained via deceleration of a high current and low energy drive beam (DB). Despite a TBL beam energy (150-80 MeV) significantly lower than the minimum nominal energy of the CLIC DB (250 MeV), the pulse time structure of the TBL provides the opportunity to measure beam losses with CLIC-like DB timing conditions. In this contribution, a simulation study on the detection of beam losses along the TBL for the commissioning of the recently installed beam loss monitoring system is presented. The most likely loss locations during stable beam conditions are studied by considering the beam envelope defined by the FODO lattice as well as the emittance growth due to the deceleration process. Moreover, the optimization of potential detector locations is discussed. Several factors are considered, namely: the distance to the beam, the shielding provided by the different elements of the line, the detector sensitivity and possible saturation effects of both the radiation detectors and electronics.

MOPF09

A Gas-Jet Profile Monitor for the CLIC Drive Beam

electron, ion, space-charge, focusing

224

A. Jeff, E.B. Holzer, T. Lefèvre
CERN, Geneva, Switzerland
A. Jeff, V. Tzoganis, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
V. Tzoganis, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

The Compact LInear Collider (CLIC) will use a novel acceleration scheme in which energy extracted from a very intense beam of relatively low-energy electrons (the Drive Beam) is used to accelerate a lower intensity Main Beam to very high energy. The high intensity of the Drive Beam, with pulses of more than 10¹⁵ electrons, poses a challenge for conventional profile measurements such as wire scanners. Thus, new non-invasive profile measurements are being investigated. Profile monitors using gas ionisation or fluorescence have been used at a number of accelerators. Typically, extra gas must be injected at the monitor and the rise in pressure spreads some distance down the beampipe. In contrast, a gas jet can be fired across the beam into a receiving chamber, with little gas escaping into the rest of the beam pipe. In addition, a gas jet shaped into a thin plane can be used like a screen on which the beam cross-section is imaged. In this paper we present some arrangements for the generation of such a jet. In addition to jet shaping using nozzles and skimmers, we propose a new scheme to use matter-wave interference with a Fresnel Zone Plate to bring an atomic jet to a narrow focus.

MOPF10

Off-Axis Undulator Radiation for CLIC Drive Beam Diagnostics

undulator, radiation, electron, transverse

228

A. Jeff, T. Lefèvre
CERN, Geneva, Switzerland
A. Jeff, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
A. Jeff, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom

The Compact LInear Collider (CLIC) will use a novel acceleration scheme in which energy extracted from a very intense beam of relatively low-energy electrons (the Drive Beam) is used to accelerate a lower intensity Main Beam to very high energy. The high intensity of the Drive Beam, with pulses of more than 10¹⁵ electrons, poses a challenge for conventional profile measurements such as wire scanners. Thus, new non-invasive profile measurements are being investigated. In this paper we propose the use of relatively inexpensive permanent-magnet undulators to generate off-axis visible Synchrotron Radiation from the CLIC Drive Beam. The field strength and period length of the undulator should be designed such that the on-axis undulator wavelength is in the ultra-violet. A smaller but still useable amount of visible light is then generated in a hollow cone. This light can be reflected out of the beam pipe by a ring-shaped mirror placed downstream and imaged on a camera. In this contribution, results of SRW and ZEMAX simulations using the CLIC Drive Beam parameters are shown.

MOPF30

Novel Diagnostics for Breakdown Studies

electron, simulation, klystron, diagnostics

287

M. Jacewicz, Ch. Borgmann, M. Olvegård, R.J.M.Y. Ruber, V.G. Ziemann
Uppsala University, Uppsala, Sweden
J.W. Kovermann
CERN, Geneva, Switzerland

The phenomenon that currently prevents achieving high accelerating gradients in high energy accelerators such as the CLIC linear collider is electrical breakdown at very high electrical field. The ongoing experimental work is trying to benchmark the theoretical models focusing on the physics of vacuum breakdown which is responsible for the discharges. The CLIC collaboration has commissioned a dedicated 12 GHz test-stand to validate the feasibility of accelerating structures and observe the characteristics of the RF discharges and their eroding effects on the structure. A versatile system for detection of the dark and breakdown currents and light emission is being developed for the test-stand. It consists of a collimation system with an external magnetic spectrometer for measurement of the spatial and energy distributions of the electrons emitted from the acceleration structure during a single RF pulse. These measurements can be correlated with e.g. the location of the breakdown inside the structure using information from the incident, reflected and transmitted RF powers giving a complete picture of the vacuum breakdown phenomenon.

TUPC12

Status of the Stripline Beam Position Monitor Development for the CLIC Drive Beam

BPM, beam-position, CTF3, impedance

384

A. Benot-Morell, L. Søby, M. Wendt
CERN, Geneva, Switzerland
A. Benot-Morell, A. Faus-Golfe
IFIC, Valencia, Spain
J.M. Nappa, S. Vilalte
IN2P3-LAPP, Annecy-le-Vieux, France
S.R. Smith
SLAC, Menlo Park, California, USA

Funding: MINECO contract FPA2010-21456-C02-01, SEIC-2010-00028, U.S. Department of Energy contract DE-AC02-76SF00515
In collaboration with SLAC, LAPP and IFIC, a first prototype of a strip-line Beam Position Monitor (BPM) for the CLIC Drive Beam and its associated readout electronics has been successfully tested in the CLIC Test Facility linac (CTF3) at CERN. In addition, a modified prototype with downstream terminated strip-lines is under development to better suppress any unwanted RF signal interference. This paper presents the results of the beam tests, the most relevant design aspects for the modified strip-line BPM version and its expected performance.

Poster TUPC12 [1.729 MB]

TUPC20

Technologies and R&D for a High Resolution Cavity BPM for the CLIC Main Beam

BPM, CTF3, pick-up, coupling

415

J.R. Towler, T. Lefèvre, L. Søby, M. Wendt
CERN, Geneva, Switzerland
S.T. Boogert, F.J. Cullinan, A. Lyapin
JAI, Egham, Surrey, United Kingdom

The Main Beam (MB) LINAC of the Compact Linear Collider (CLIC) requires a beam orbit measurement system with a high spatial (50 nm) and high temporal (50 ns) resolution to resolve the beam position within the 156 ns long bunch train, traveling on an energy-chirped, minimum dispersive trajectory. A 15 GHz prototype cavity BPM has been commissioned in the probe beam-line of the CTF3 CLIC Test Facility. The performance and technical details of this prototype installation are discussed in this paper, including the 15 GHz analog down-converter, the data acquisition and the control electronics and software. An R&D outlook is given for the next steps, which requires a system of 3 cavity BPMs to investigate the full resolution potential.

TUPC41

A Femtosecond Resolution Electro-Optic Diagnostic Using a Nanosecond-Pulse Laser

laser, diagnostics, alignment, longitudinal

474

S.P. Jamison
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
W.A. Gillespie, D.A. Walsh
University of Dundee, Nethergate, Dundee, Scotland, United Kingdom

Funding: We gratefully acknowledge support under CERN collaboration agreement KE1865/TE
Electro-optic longitudinal profile diagnostic systems with intrinsically improved reliability and a time resolution of 20 fs rms are being developed for CLIC. Exploiting the electro-optic effect, the bunch electric field 'pulse carves' an optical replica from a narrow bandwidth nanosecond duration laser probe. All-optical characterisation of the optical replica is via spectrally resolved auto-correlation, providing a sub-20fs resolution capability. An optical parametric amplification stage following the pulse carving, and driven by same nanosecond laser that provides the probe, enables sufficient intensity for single-shot measurement. In basing the optical system on nanosecond Q-switched lasers, bypassing complex femtosecond laser systems, the potential for robust instrumentation development is enhanced. The bandwidth limitations of the electro-optic materials are being addressed through investigations into multiple crystal detectors, and THz induced second harmonic generation on metal surfaces. Experimental results on the optical subsystems, using laser-produced THz as an electron bunch mimic, are presented together with performance projections for the integrated system.

WEAL3

Diffraction Radiation Test at CesrTA for Non-Intercepting Micron-Scale Beam Size Measurement

target, radiation, electron, CERN

619

L.M. Bobb, E. Bravin, T. Lefèvre, S. Mazzoni
CERN, Geneva, Switzerland
T. Aumeyr, P. Karataev
Royal Holloway, University of London, Surrey, United Kingdom
M.G. Billing, J.V. Conway
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
L.M. Bobb
JAI, Egham, Surrey, United Kingdom

Diffraction radiation (DR) is produced when a relativistic charged particle moves in the vicinity of a medium. The electric field of the charged particle polarizes the target atoms which then oscillate, emitting radiation with a very broad spectrum. The spatial-spectral properties of DR are sensitive to a range of electron beam parameters. Furthermore, the energy loss due to DR is so small that the electron beam parameters are unchanged. DR can therefore be used to develop non-invasive diagnostic tools. To achieve the micron-scale resolution required to measure the transverse (vertical) beam size using incoherent DR in CLIC, DR in UV and X-ray spectral-range must be investigated. Experimental validation of such a scheme is ongoing at CesrTA at Cornell University, USA. Here we report on the test using 0.5 mm and 1 mm target apertures on a 2.1 GeV electron beam and 400 nm wavelength.

Slides WEAL3 [2.893 MB]

WEPC43

Update on Beam Loss Monitoring at CTF3 for CLIC

DIAMOND, beam-losses, photon, quadrupole

787

L.J. Devlin, S. Mallows, C.P. Welsch, E.N. del Busto
Cockcroft Institute, Warrington, Cheshire, United Kingdom
E. Branger
Linköping University, Linköping, Sweden
L.J. Devlin, S. Mallows, C.P. Welsch, E.N. del Busto
The University of Liverpool, Liverpool, United Kingdom
E. Effinger, E.B. Holzer, S. Mallows, E.N. del Busto
CERN, Geneva, Switzerland

Funding: Work supported by STFC Cockcroft Institute Core Grant No. ST/G008248/1
The primary role of the beam loss monitoring (BLM) system for the compact linear collider (CLIC) study is to work within the machine protection system. Due to the size of the CLIC facility, a BLM that covers large distances along the beamline is highly desirable, in particular for the CLIC drive beam decelerators, which would alternatively require some ~40,000 localised monitors. Therefore, an optical fiber BLM system is currently under investigation which can cover large sections of beamline at a time. A multimode fiber has been installed along the Test Beam Line at the CLIC test facility (CTF3) where the detection principle is based on the production of Cherenkov photons within the fiber resulting from beam loss and their subsequent transport along the fiber where they are then detected at the fiber ends using silicon photomultipliers. Several additional monitors including ACEMs, PEP-II and diamond detectors have also been installed. In this contribution the first results from the BLMs are presented, comparisons of the signals from each BLM are made and the possible achievable longitudinal resolution from the fiber BLM signal considering various loss patterns is discussed.

WEPC46

Beam Delivery Simulation (BDSIM): A Geant4 Based Toolkit for Diagnostics and Loss Simulation

LHC, simulation, lattice, background

799

S.T. Boogert
Royal Holloway, University of London, Surrey, United Kingdom
S.T. Boogert, S.M. Gibson, R. Kwee-Hinzmann, L.J. Nevay, J. Snuverink
JAI, Egham, Surrey, United Kingdom
L.C. Deacon
CERN, Geneva, Switzerland

BDSIM is a Geant4 and C++ based particle tracking code which seamlessly tracks particles in accelerators and particle detectors, including the full range of particle interaction physics processes in Geant4. The code has been used to model the backgrounds in the International Linear Collider (ILC), Compact Linear Collider (CLIC), Accelerator Test Facility 2 (ATF2) and more recently the Large Hadron Collider (LHC). This paper outlines the current code and possible example applications and presents a roadmap for future developments.