IPAC2013 - List of Authors (Tecker, F.)

Paper	Title	Page
MOPWA038	Flashbox Compact Beam Spectrometer and its Application to the High-gradient Acceleration Study	753
	A. Dubrovskiy, F. Tecker CERN, Geneva, Switzerland M. Jacewicz, R.J.M.Y. Ruber, V.G. Ziemann Uppsala University, Uppsala, Sweden
	A Flashbox compact spectrometer has been developed for the Two-beam Test Stand (TBTS), which is a part of the CLIC test facility CTF3 at CERN. It is used to study limitations of high-gradient acceleration in X-band structures being prototyped in the TBTS. The Flashbox is built around the beam tube such that an electron beam can pass to be accelerated in the X-band structure while charged particles emitted from the accelerating structure can be intercepted on the spectrometer consisting of detector plates aligned along the beam axis in combination with magnetic and electric fields. The Flashbox has made it possible to identify electrons and ions emitted by the accelerating structure during RF breakdown. We describe the Flashbox and first results.

TUPFI040	Experimental Verification of the CLIC Two-Beam Acceleration Technology in CTF3	1436
	P. Skowroński, A. Andersson, J. Barranco, B. Constance, R. Corsini, S. Döbert, A. Dubrovskiy, W. Farabolini, E. Ikarios, R.L. Lillestøl, T. Persson, F. Tecker CERN, Geneva, Switzerland W. Farabolini CEA/DSM/IRFU, France E. Ikarios National Technical University of Athens, Athens, Greece M. Jacewicz, A. Palaia, R.J.M.Y. Ruber Uppsala University, Uppsala, Sweden R.L. Lillestøl University of Oslo, Oslo, Norway T. Persson Chalmers University of Technology, Chalmers Tekniska Högskola, Gothenburg, Sweden
	The Compact Linear Collider (CLIC) International Collaboration is pursuing an extensive R&D program towards a multi-TeV electron-positron collider. In particular, the development of two beam acceleration technology is the focus of the CLIC test facility CTF3. In this paper we summarize the most recent results obtained at CTF3: the results of the studies on the drive beam generation are presented, the achieved two beam acceleration performance is reported and the measured break-down rates and related observations are summarized. The stability of deceleration process performed over 13 subsequent modules and the comparison of the obtained results with the theoretical expectations are discussed. We also outline and discuss the future experimental program.

TUPME039	The Drive Beam Phase Stability in CTF3 and its Relation to the Bunch Compression Factor	1655
	E. Ikarios, A. Andersson, J. Barranco, B. Constance, R. Corsini, A. Gerbershagen, T. Persson, P. Skowroński, F. Tecker CERN, Geneva, Switzerland
	The proposed Compact Linear Collider (CLIC) is based on a two-beam acceleration scheme. The energy needed to accelerate a low intensity "main" beam is provided by a high intensity, low energy "drive" beam. The precision and stability of the phase relation between two beams is crucial for the performance of the scheme. The tolerable phase jitter is 0.2 deg rms at 12GHz. For this reason it is fundamental to understand the main possible causes of the drive beam timing jitter. Experimental work aimed at such understanding was done in the CLIC Test Facility (CTF3) where a drive beam with characteristics similar to the CLIC one is produced. Several phase measurements allowed us to conclude that the main source of phase jitter is energy jitter of the beam transformed and amplified into phase jitter when passing through a magnetic chicane. This conclusion is supported by measurements done with different momentum compaction values in the chicane. In this paper the results of these several phase measurements will be presented and compared with expectations.

TUPME054	Experimental Study of the Effect of Beam Loading on RF Breakdown Rate in CLIC High-gradient Accelerating Structures	1691
	F. Tecker, R. Corsini, M. Dayyani Kelisani, S. Döbert, A. Grudiev, O. Kononenko, S. Lebet, J.L. Navarro Quirante, G. Riddone, I. Syratchev, W. Wuensch CERN, Geneva, Switzerland A. Solodko JINR, Dubna, Moscow Region, Russia
	RF breakdown is a key issue for the multi-TeV high-luminosity e⁺e⁻ Compact Linear Collider (CLIC). Breakdowns in the high-gradient accelerator structures can deflect the beam and decrease the desired luminosity. The limitations of the accelerating structures due to breakdowns have been studied so far without a beam present in the structure. The presence of the beam modifies the distribution of the electrical and magnetic field distributions, which determine the breakdown rate. Therefore an experiment has been designed for high power testing a CLIC prototype accelerating structure with a beam present in the CLIC Test Facility (CTF3). A special beam line allows extracting a beam with nominal CLIC beam current and duration from the CTF3 linac. The paper describes the beam optics design for this experimental beam line and the commissioning of the experiment with beam.

WEPEA069	Review of the Drive Beam Stabilization in the CLIC Test Facility CTF3	2666
	A. Dubrovskiy, L. Malina, P. Skowroński, F. Tecker CERN, Geneva, Switzerland T. Persson Chalmers University of Technology, Chalmers Tekniska Högskola, Gothenburg, Sweden
	CTF3 is a Test Facility focusing on beam-based studies of the key concepts of the Compact Linear Collider CLIC. Over the past several years many aspects the CLIC two-beam acceleration scheme were studied in CTF3, including the crucial issue of drive beam stability. The main sources of drifts and instabilities have been identified and mitigated, helping to improve the machine performance and showing significant progress towards the experimental demonstration of the very stringent requirements on current, energy and phase stability needed in CLIC. In this paper, the more effective techniques and feed-backs are summarized. The latest measurements on beam stability are reported and their relevance to CLIC is discussed.

Paper

Title

Page

Flashbox Compact Beam Spectrometer and its Application to the High-gradient Acceleration Study

753

A. Dubrovskiy, F. Tecker
CERN, Geneva, Switzerland
M. Jacewicz, R.J.M.Y. Ruber, V.G. Ziemann
Uppsala University, Uppsala, Sweden

A Flashbox compact spectrometer has been developed for the Two-beam Test Stand (TBTS), which is a part of the CLIC test facility CTF3 at CERN. It is used to study limitations of high-gradient acceleration in X-band structures being prototyped in the TBTS. The Flashbox is built around the beam tube such that an electron beam can pass to be accelerated in the X-band structure while charged particles emitted from the accelerating structure can be intercepted on the spectrometer consisting of detector plates aligned along the beam axis in combination with magnetic and electric fields. The Flashbox has made it possible to identify electrons and ions emitted by the accelerating structure during RF breakdown. We describe the Flashbox and first results.

TUPFI040

Experimental Verification of the CLIC Two-Beam Acceleration Technology in CTF3

1436

P. Skowroński, A. Andersson, J. Barranco, B. Constance, R. Corsini, S. Döbert, A. Dubrovskiy, W. Farabolini, E. Ikarios, R.L. Lillestøl, T. Persson, F. Tecker
CERN, Geneva, Switzerland
W. Farabolini
CEA/DSM/IRFU, France
E. Ikarios
National Technical University of Athens, Athens, Greece
M. Jacewicz, A. Palaia, R.J.M.Y. Ruber
Uppsala University, Uppsala, Sweden
R.L. Lillestøl
University of Oslo, Oslo, Norway
T. Persson
Chalmers University of Technology, Chalmers Tekniska Högskola, Gothenburg, Sweden

The Compact Linear Collider (CLIC) International Collaboration is pursuing an extensive R&D program towards a multi-TeV electron-positron collider. In particular, the development of two beam acceleration technology is the focus of the CLIC test facility CTF3. In this paper we summarize the most recent results obtained at CTF3: the results of the studies on the drive beam generation are presented, the achieved two beam acceleration performance is reported and the measured break-down rates and related observations are summarized. The stability of deceleration process performed over 13 subsequent modules and the comparison of the obtained results with the theoretical expectations are discussed. We also outline and discuss the future experimental program.

TUPME039

The Drive Beam Phase Stability in CTF3 and its Relation to the Bunch Compression Factor

1655

E. Ikarios, A. Andersson, J. Barranco, B. Constance, R. Corsini, A. Gerbershagen, T. Persson, P. Skowroński, F. Tecker
CERN, Geneva, Switzerland

The proposed Compact Linear Collider (CLIC) is based on a two-beam acceleration scheme. The energy needed to accelerate a low intensity "main" beam is provided by a high intensity, low energy "drive" beam. The precision and stability of the phase relation between two beams is crucial for the performance of the scheme. The tolerable phase jitter is 0.2 deg rms at 12GHz. For this reason it is fundamental to understand the main possible causes of the drive beam timing jitter. Experimental work aimed at such understanding was done in the CLIC Test Facility (CTF3) where a drive beam with characteristics similar to the CLIC one is produced. Several phase measurements allowed us to conclude that the main source of phase jitter is energy jitter of the beam transformed and amplified into phase jitter when passing through a magnetic chicane. This conclusion is supported by measurements done with different momentum compaction values in the chicane. In this paper the results of these several phase measurements will be presented and compared with expectations.

TUPME054

Experimental Study of the Effect of Beam Loading on RF Breakdown Rate in CLIC High-gradient Accelerating Structures

1691

F. Tecker, R. Corsini, M. Dayyani Kelisani, S. Döbert, A. Grudiev, O. Kononenko, S. Lebet, J.L. Navarro Quirante, G. Riddone, I. Syratchev, W. Wuensch
CERN, Geneva, Switzerland
A. Solodko
JINR, Dubna, Moscow Region, Russia

RF breakdown is a key issue for the multi-TeV high-luminosity e⁺e⁻ Compact Linear Collider (CLIC). Breakdowns in the high-gradient accelerator structures can deflect the beam and decrease the desired luminosity. The limitations of the accelerating structures due to breakdowns have been studied so far without a beam present in the structure. The presence of the beam modifies the distribution of the electrical and magnetic field distributions, which determine the breakdown rate. Therefore an experiment has been designed for high power testing a CLIC prototype accelerating structure with a beam present in the CLIC Test Facility (CTF3). A special beam line allows extracting a beam with nominal CLIC beam current and duration from the CTF3 linac. The paper describes the beam optics design for this experimental beam line and the commissioning of the experiment with beam.

WEPEA069

Review of the Drive Beam Stabilization in the CLIC Test Facility CTF3

2666

A. Dubrovskiy, L. Malina, P. Skowroński, F. Tecker
CERN, Geneva, Switzerland
T. Persson
Chalmers University of Technology, Chalmers Tekniska Högskola, Gothenburg, Sweden

CTF3 is a Test Facility focusing on beam-based studies of the key concepts of the Compact Linear Collider CLIC. Over the past several years many aspects the CLIC two-beam acceleration scheme were studied in CTF3, including the crucial issue of drive beam stability. The main sources of drifts and instabilities have been identified and mitigated, helping to improve the machine performance and showing significant progress towards the experimental demonstration of the very stringent requirements on current, energy and phase stability needed in CLIC. In this paper, the more effective techniques and feed-backs are summarized. The latest measurements on beam stability are reported and their relevance to CLIC is discussed.