IPAC2013 - List of Authors (Christian, G.B.)

Paper

Title

Page

Development of a High-resolution, Broad-band, Stripline Beam Position Monitoring System

804

G.B. Christian, D.R. Bett, N. Blaskovic Kraljevic, P. Burrows, M.R. Davis, Y.I. Kim, C. Perry
JAI, Oxford, United Kingdom
R. Apsimon, B. Constance
CERN, Geneva, Switzerland
P. Burrows, C. Perry
Oxford University, Physics Department, Oxford, Oxon, United Kingdom
J. Resta
IFIC, Valencia, Spain

A low-latency, sub-micron resolution stripline beam position monitoring system has been developed and tested with beam at the KEK Accelerator Test Facility, where it has been used as part of a feedback system for beam stabilisation. The fast analogue front-end signal processor is based on a single-stage down-mixer and is combined with an FPGA-based system for digitisation and feedback control. A resolution as low as 400 nm has been demonstrated for beam intensities of ~1 nC, with single-pass beam. The latest results of recent modifications to balance the input path lengths to the processor will be discussed. These modifications compensate for the inherent phase sensitivity of the processors, and hence improve the intrinsic resolution, without the need for offline correction. Modifications to the FPGA firmware will also be described, to allow for flexible operation with variable system-synchronous data acquisition at up to 400 MHz, with up to nine data channels of 13-bit width, and a nominal record length of 1 KS/channel/pulse (extensible to a total record length of 120 KS per pulse, for example, for use with long bunch trains or wide-band multi-turn measurements in storage rings).

MOPWA058

Cavity Beam Position Monitor at Interaction Point Region of Accelerator Test Facility 2

807

Y.I. Kim, D.R. Bett, N. Blaskovic Kraljevic, P. Burrows, G.B. Christian, M.R. Davis, A. Lyapin
JAI, Egham, Surrey, United Kingdom
S.T. Boogert
Royal Holloway, University of London, Surrey, United Kingdom
J.C. Frisch, D.J. McCormick, J. Nelson, G.R. White
SLAC, Menlo Park, California, USA
Y. Honda, T. Tauchi, N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan

Nanometre resolution cavity beam position monitors (BPMs) have been developed to measure the beam position and linked to a feedback system control the beam position stability within few nanometres in the vertical direction at the focus, or interaction point (IP), of Accelerator Test Facility 2 (ATF2). In addition, for feedback applications a lower-Q and hence faster decay time system is desirable. Two IPBPMs have been installed inside of IP chamber at the ATF2 focus area. To measure the resolution of IPBPMs two additional C-band cavity BPMs have been installed one upstream and one downstream of the IP. One cavity BPM has been installed at an upstream image point of IP. The performance of the BPMs is discussed and the correlation between IP and image point positions is presented along with a discussion of using these BPMs for position stabilisation at the IP.

WEOBB203

Design of Phase Feed Forward System in CTF3 and Performance of Fast Beam Phase Monitors

2097

P. Skowroński, A. Andersson, A. Gerbershagen, E. Ikarios, J. Roberts
CERN, Geneva, Switzerland
P. Burrows, G.B. Christian, A. Gerbershagen, C. Perry, J. Roberts
JAI, Oxford, United Kingdom
P. Burrows, G.B. Christian, A. Gerbershagen, C. Perry
Oxford University, Physics Department, Oxford, Oxon, United Kingdom
A. Ghigo, F. Marcellini
INFN/LNF, Frascati (Roma), Italy
E. Ikarios
National Technical University of Athens, Athens, Greece

Funding: Work supported by the European Commission under the FP7 Research Infrastructures project Eu- CARD, grant agreement no. 227579
The CLIC two beam acceleration technology requires a drive beam phase stability of better than 0.3 deg rms at 12 GHz, corresponding to a timing stability below 50 fs rms. For this reason the CLIC design includes a phase stabilization feed-forward system. It relies on precise beam phase measurement and its subsequent correction in a chicane with help of fast kickers. A prototype of such a system is being installed in CLIC Test Facility CTF3. In this paper we describe in detail its design and implementation. Additionally, we present and discuss the performance of the precision phase monitor prototypes installed at the end of the CTF3 linac, measured with the drive beam.
We would like to acknowledge support of G.Sensolini, A.Zolla (INFN/LNF Frascati), N.S.Chritin and J-M.Scigliuto (CERN) in design and fabrication of components.

Slides WEOBB203 [6.770 MB]

WEPME053

Latest Performance Results from the FONT 5 Intra Train Beam Position Feedback System at ATF

3049

M.R. Davis, D.R. Bett, N. Blaskovic Kraljevic, P. Burrows, G.B. Christian, Y.I. Kim, C. Perry
JAI, Oxford, United Kingdom
R. Apsimon, B. Constance, A. Gerbershagen
CERN, Geneva, Switzerland

A prototype ultra-fast beam-based feedback system for deployment in single-pass beamlines, such as a future lepton collider (ILC or CLIC) or a free-electron laser, has been fabricated and is being tested in the extraction and final focus lines of the Accelerator Test Facility (ATF) at KEK. FONT5 is an intra-train feedback system for stabilising the beam orbit via different methods: a position and angle feedback correction in the extraction line or a vertical feedforward correction applied at the interaction point (IP) . Two systems comprise three stripline beam position monitors (BPMs) and two stripline kickers in the extraction line, two cavity BPMs and a stripline kicker at the IP, a custom FPGA-based digital processing board, custom kicker-drive amplifiers and low-latency analogue front-end BPM processors. Latest results from the experiment are presented. These include beam position correction in the extraction line, as well as preliminary results of beam correction at the IP.

WEOBB203

Design of Phase Feed Forward System in CTF3 and Performance of Fast Beam Phase Monitors

2097

P. Skowroński, A. Andersson, A. Gerbershagen, E. Ikarios, J. Roberts
CERN, Geneva, Switzerland
P. Burrows, G.B. Christian, A. Gerbershagen, C. Perry, J. Roberts
JAI, Oxford, United Kingdom
P. Burrows, G.B. Christian, A. Gerbershagen, C. Perry
Oxford University, Physics Department, Oxford, Oxon, United Kingdom
A. Ghigo, F. Marcellini
INFN/LNF, Frascati (Roma), Italy
E. Ikarios
National Technical University of Athens, Athens, Greece

Funding: Work supported by the European Commission under the FP7 Research Infrastructures project Eu- CARD, grant agreement no. 227579
The CLIC two beam acceleration technology requires a drive beam phase stability of better than 0.3 deg rms at 12 GHz, corresponding to a timing stability below 50 fs rms. For this reason the CLIC design includes a phase stabilization feed-forward system. It relies on precise beam phase measurement and its subsequent correction in a chicane with help of fast kickers. A prototype of such a system is being installed in CLIC Test Facility CTF3. In this paper we describe in detail its design and implementation. Additionally, we present and discuss the performance of the precision phase monitor prototypes installed at the end of the CTF3 linac, measured with the drive beam.
We would like to acknowledge support of G.Sensolini, A.Zolla (INFN/LNF Frascati), N.S.Chritin and J-M.Scigliuto (CERN) in design and fabrication of components.

Slides WEOBB203 [6.770 MB]

Paper	Title	Page
MOPWA057	Development of a High-resolution, Broad-band, Stripline Beam Position Monitoring System	804
	G.B. Christian, D.R. Bett, N. Blaskovic Kraljevic, P. Burrows, M.R. Davis, Y.I. Kim, C. Perry JAI, Oxford, United Kingdom R. Apsimon, B. Constance CERN, Geneva, Switzerland P. Burrows, C. Perry Oxford University, Physics Department, Oxford, Oxon, United Kingdom J. Resta IFIC, Valencia, Spain
	A low-latency, sub-micron resolution stripline beam position monitoring system has been developed and tested with beam at the KEK Accelerator Test Facility, where it has been used as part of a feedback system for beam stabilisation. The fast analogue front-end signal processor is based on a single-stage down-mixer and is combined with an FPGA-based system for digitisation and feedback control. A resolution as low as 400 nm has been demonstrated for beam intensities of ~1 nC, with single-pass beam. The latest results of recent modifications to balance the input path lengths to the processor will be discussed. These modifications compensate for the inherent phase sensitivity of the processors, and hence improve the intrinsic resolution, without the need for offline correction. Modifications to the FPGA firmware will also be described, to allow for flexible operation with variable system-synchronous data acquisition at up to 400 MHz, with up to nine data channels of 13-bit width, and a nominal record length of 1 KS/channel/pulse (extensible to a total record length of 120 KS per pulse, for example, for use with long bunch trains or wide-band multi-turn measurements in storage rings).

MOPWA058	Cavity Beam Position Monitor at Interaction Point Region of Accelerator Test Facility 2	807
	Y.I. Kim, D.R. Bett, N. Blaskovic Kraljevic, P. Burrows, G.B. Christian, M.R. Davis, A. Lyapin JAI, Egham, Surrey, United Kingdom S.T. Boogert Royal Holloway, University of London, Surrey, United Kingdom J.C. Frisch, D.J. McCormick, J. Nelson, G.R. White SLAC, Menlo Park, California, USA Y. Honda, T. Tauchi, N. Terunuma, J. Urakawa KEK, Ibaraki, Japan
	Nanometre resolution cavity beam position monitors (BPMs) have been developed to measure the beam position and linked to a feedback system control the beam position stability within few nanometres in the vertical direction at the focus, or interaction point (IP), of Accelerator Test Facility 2 (ATF2). In addition, for feedback applications a lower-Q and hence faster decay time system is desirable. Two IPBPMs have been installed inside of IP chamber at the ATF2 focus area. To measure the resolution of IPBPMs two additional C-band cavity BPMs have been installed one upstream and one downstream of the IP. One cavity BPM has been installed at an upstream image point of IP. The performance of the BPMs is discussed and the correlation between IP and image point positions is presented along with a discussion of using these BPMs for position stabilisation at the IP.

WEOBB203	Design of Phase Feed Forward System in CTF3 and Performance of Fast Beam Phase Monitors	2097
	P. Skowroński, A. Andersson, A. Gerbershagen, E. Ikarios, J. Roberts CERN, Geneva, Switzerland P. Burrows, G.B. Christian, A. Gerbershagen, C. Perry, J. Roberts JAI, Oxford, United Kingdom P. Burrows, G.B. Christian, A. Gerbershagen, C. Perry Oxford University, Physics Department, Oxford, Oxon, United Kingdom A. Ghigo, F. Marcellini INFN/LNF, Frascati (Roma), Italy E. Ikarios National Technical University of Athens, Athens, Greece
	Funding: Work supported by the European Commission under the FP7 Research Infrastructures project Eu- CARD, grant agreement no. 227579 The CLIC two beam acceleration technology requires a drive beam phase stability of better than 0.3 deg rms at 12 GHz, corresponding to a timing stability below 50 fs rms. For this reason the CLIC design includes a phase stabilization feed-forward system. It relies on precise beam phase measurement and its subsequent correction in a chicane with help of fast kickers. A prototype of such a system is being installed in CLIC Test Facility CTF3. In this paper we describe in detail its design and implementation. Additionally, we present and discuss the performance of the precision phase monitor prototypes installed at the end of the CTF3 linac, measured with the drive beam. We would like to acknowledge support of G.Sensolini, A.Zolla (INFN/LNF Frascati), N.S.Chritin and J-M.Scigliuto (CERN) in design and fabrication of components.
	Slides WEOBB203 [6.770 MB]

WEPME053	Latest Performance Results from the FONT 5 Intra Train Beam Position Feedback System at ATF	3049
	M.R. Davis, D.R. Bett, N. Blaskovic Kraljevic, P. Burrows, G.B. Christian, Y.I. Kim, C. Perry JAI, Oxford, United Kingdom R. Apsimon, B. Constance, A. Gerbershagen CERN, Geneva, Switzerland
	A prototype ultra-fast beam-based feedback system for deployment in single-pass beamlines, such as a future lepton collider (ILC or CLIC) or a free-electron laser, has been fabricated and is being tested in the extraction and final focus lines of the Accelerator Test Facility (ATF) at KEK. FONT5 is an intra-train feedback system for stabilising the beam orbit via different methods: a position and angle feedback correction in the extraction line or a vertical feedforward correction applied at the interaction point (IP) . Two systems comprise three stripline beam position monitors (BPMs) and two stripline kickers in the extraction line, two cavity BPMs and a stripline kicker at the IP, a custom FPGA-based digital processing board, custom kicker-drive amplifiers and low-latency analogue front-end BPM processors. Latest results from the experiment are presented. These include beam position correction in the extraction line, as well as preliminary results of beam correction at the IP.

WEOBB203	Design of Phase Feed Forward System in CTF3 and Performance of Fast Beam Phase Monitors	2097
	P. Skowroński, A. Andersson, A. Gerbershagen, E. Ikarios, J. Roberts CERN, Geneva, Switzerland P. Burrows, G.B. Christian, A. Gerbershagen, C. Perry, J. Roberts JAI, Oxford, United Kingdom P. Burrows, G.B. Christian, A. Gerbershagen, C. Perry Oxford University, Physics Department, Oxford, Oxon, United Kingdom A. Ghigo, F. Marcellini INFN/LNF, Frascati (Roma), Italy E. Ikarios National Technical University of Athens, Athens, Greece
	Funding: Work supported by the European Commission under the FP7 Research Infrastructures project Eu- CARD, grant agreement no. 227579 The CLIC two beam acceleration technology requires a drive beam phase stability of better than 0.3 deg rms at 12 GHz, corresponding to a timing stability below 50 fs rms. For this reason the CLIC design includes a phase stabilization feed-forward system. It relies on precise beam phase measurement and its subsequent correction in a chicane with help of fast kickers. A prototype of such a system is being installed in CLIC Test Facility CTF3. In this paper we describe in detail its design and implementation. Additionally, we present and discuss the performance of the precision phase monitor prototypes installed at the end of the CTF3 linac, measured with the drive beam. We would like to acknowledge support of G.Sensolini, A.Zolla (INFN/LNF Frascati), N.S.Chritin and J-M.Scigliuto (CERN) in design and fabrication of components.
	Slides WEOBB203 [6.770 MB]