IPAC2016 - List of Authors (Burrows, P.)

Paper	Title	Page
WEPOR006	Demonstration of CLIC Level Phase Stability using a High Bandwidth, Low Latency Drive Beam Phase Feedforward System at the CLIC Test Facility CTF3	2673
	J. Roberts, P. Burrows, G.B. Christian, C. Perry JAI, Oxford, United Kingdom A. Andersson, R. Corsini, P.K. Skowroński CERN, Geneva, Switzerland A. Ghigo, F. Marcellini INFN/LNF, Frascati (Roma), Italy
	Funding: Work supported by the European Commission under the FP7 Research Infrastructures project Eu-CARD, grant agreement no.~227579. The CLIC acceleration scheme, in which the RF power used to accelerate the main high energy beam is extracted from a second high intensity but low energy beam, places strict requirements on the phase stability of the power producing drive beam. To limit luminosity loss caused by energy jitter leading to emittance growth in the final focus to below 1%, 0.2 degrees of 12 GHz, or 50 fs, drive beam phase stability is needed. A low-latency phase feedforward correction with bandwidth above 17.5 MHz will be used to reduce the drive beam phase jitter to this level. The proposed scheme corrects the phase using fast electromagnetic kickers to vary the path length in a chicane prior to the drive beam power extraction. A prototype of this system has been installed at the CLIC test facility CTF3 to prove its feasibility. The latest results from the system are presented, demonstrating phase stabilisation in agreement with simulations given the beam conditions and power of the kicker amplifiers. Necessary improvements in the phase monitor performance and optics corrections made to remove the phase-energy dependence via R56 in order to achieve this level of stability are also discussed.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOR006
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WEPOR009	Intra-beam IP Feedback Studies for the 380 GeV CLIC Beam Delivery System	2683
	R.M. Bodenstein, P. Burrows, J. Snuverink JAI, Egham, Surrey, United Kingdom F. Plassard CERN, Geneva, Switzerland
	In its currently-envisaged initial stage, the Compact Linear Collider (CLIC) will collide beams with a 380 GeV center of mass energy. To maintain the luminosity within a few percent of the design value, beam stability at the interaction point (IP) must be controlled at the sub-nanometer level. To help achieve such control, use of an intra-pulse IP feedback system is planned. With CLIC's very short bunch spacing of 0.5 ns, and nominal pulse duration of 176 ns, this feedback system presents a significant technical challenge. Furthermore, as part of a study to optimize the design of the beam delivery system (BDS), several L* configurations have been studied. In this paper, we will review the IP feedback simulations for the 380 GeV machine for two L* configurations, and compare luminosity recovery performance with that of the original L* configuration in the 3 TeV machine.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOR009
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THOAA02	The Development of C-Band Cavity Beam Position Monitor with a Position Resolution of Nano Meter	3149
	S.W. Jang, E.-S. Kim Korea University Sejong Campus, Sejong, Republic of Korea P. Bambade, O.R. Blanco-García, S. Wallon LAL, Orsay, France N. Blaskovic Kraljevic, T. Bromwich, P. Burrows JAI, Oxford, United Kingdom T. Tauchi, N. Terunuma KEK, Ibaraki, Japan
	We developed and tested an C-band beam position monitor with position resolution of nano meter in ATF2. The C-band BPM was developed for the fast beam feedback system at the interaction point of ATF in KEK, which C-band beam position monitor called to IPBPM (Interaction Point Beam Position Monitor). The developed IPBPM was measured 26nm with 30% of nominal beam charge of ATF. From the measured beam position resolution, we can expected to 8nm beam position resolution with nominal ATF beam charge condition. In this talk, we will described about the development of IPBPM and the beam test results of nano meter level beam position resolution.
	Slides THOAA02 [4.806 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THOAA02
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THPOR032	Effect and Optimisation of Non-Linear Chromatic Aberrations of the CLIC Drive Beam Recombination at CTF3	3852
	D. Gamba, R. Corsini, P.K. Skowroński, F. Tecker CERN, Geneva, Switzerland P. Burrows JAI, Oxford, United Kingdom P. Burrows Oxford University, Physics Department, Oxford, Oxon, United Kingdom
	The CLIC design relies on the two-beam acceleration principle, i.e. the energy transfer from the so called drive beam to the main colliding beams. At the CLIC Test Facility (CTF3) at CERN the feasibility of this principle is being tested in terms of performance and achievable specifications. The high-current drive beam is generated by recombining its parts in a delay loop and a combiner ring. Preserving the drive beam emittance during the recombination process is crucial to ensure beam-current and power production stability. Present theoretical and experimental studies show that non-linear energy dependence of the transverse optics heavily spoils the quality of the recombined beam. Conventionally these effects are cured by means of non-linear corrections using sextupoles. In this work we propose a mitigation of these effects by optimising the linear lattice, leading to a more robust and easy to operate drive beam recombination complex. The latest results are presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR032
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THPOR034	Bunch-by-bunch Position and Angle Stabilisation at ATF based on Sub-micron Resolution Stripline Beam Position Monitors	3859
	N. Blaskovic Kraljevic, R.M. Bodenstein, T. Bromwich, P. Burrows, G.B. Christian, M.R. Davis, C. Perry, R.L. Ramjiawan JAI, Oxford, United Kingdom D.R. Bett CERN, Geneva, Switzerland
	A low-latency, sub-micron resolution stripline beam position monitoring (BPM) system has been developed and tested with beam at the KEK Accelerator Test Facility (ATF2), where it has been used to drive a beam stabilisation system. The fast analogue front-end signal processor is based on a single-stage radio-frequency down-mixer, with a measured latency of 16 ns and a demonstrated single-pass beam position resolution of below 300 nm using a beam with a bunch charge of approximately 1 nC. The BPM position data are digitised on a digital feedback board which is used to drive a pair of kickers local to the BPMs and nominally orthogonal in phase in closed-loop feedback mode, thus achieving both beam position and angle stabilisation. We report the reduction in jitter as measured at a witness stripline BPM located 30 metres downstream of the feedback system and its propagation to the ATF interaction point.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR034
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THPOR035	Development of a Low-latency, Micrometre-level Precision, Intra-train Beam Feedback System based on Cavity Beam Position Monitors	3862
	N. Blaskovic Kraljevic, R.M. Bodenstein, T. Bromwich, P. Burrows, G.B. Christian, M.R. Davis, C. Perry, R.L. Ramjiawan JAI, Oxford, United Kingdom D.R. Bett CERN, Geneva, Switzerland
	A low-latency, intra-train, beam feedback system utilising a cavity beam position monitor (BPM) has been developed and tested at the final focus of the Accelerator Test Facility (ATF2) at KEK. A low-Q cavity BPM was utilised with custom signal processing electronics, designed for low latency and optimal position resolution, to provide an input beam position signal to the feedback system. A custom stripline kicker and power amplifier, and a digital feedback board, were used to provide beam correction and feedback control, respectively. The system was deployed in single-pass, multi-bunch mode with the aim of demonstrating intra-train beam stabilisation on electron bunches of charge ~1 nC separated in time by c. 220 ns. The system has been used to demonstrate beam stabilisation to below the 75 nm level. Results of the latest beam tests, aimed at even higher performance, will be presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR035
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Demonstration of CLIC Level Phase Stability using a High Bandwidth, Low Latency Drive Beam Phase Feedforward System at the CLIC Test Facility CTF3

2673

J. Roberts, P. Burrows, G.B. Christian, C. Perry
JAI, Oxford, United Kingdom
A. Andersson, R. Corsini, P.K. Skowroński
CERN, Geneva, Switzerland
A. Ghigo, F. Marcellini
INFN/LNF, Frascati (Roma), Italy

Funding: Work supported by the European Commission under the FP7 Research Infrastructures project Eu-CARD, grant agreement no.~227579.
The CLIC acceleration scheme, in which the RF power used to accelerate the main high energy beam is extracted from a second high intensity but low energy beam, places strict requirements on the phase stability of the power producing drive beam. To limit luminosity loss caused by energy jitter leading to emittance growth in the final focus to below 1%, 0.2 degrees of 12 GHz, or 50 fs, drive beam phase stability is needed. A low-latency phase feedforward correction with bandwidth above 17.5 MHz will be used to reduce the drive beam phase jitter to this level. The proposed scheme corrects the phase using fast electromagnetic kickers to vary the path length in a chicane prior to the drive beam power extraction. A prototype of this system has been installed at the CLIC test facility CTF3 to prove its feasibility. The latest results from the system are presented, demonstrating phase stabilisation in agreement with simulations given the beam conditions and power of the kicker amplifiers. Necessary improvements in the phase monitor performance and optics corrections made to remove the phase-energy dependence via R56 in order to achieve this level of stability are also discussed.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOR006

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WEPOR009

Intra-beam IP Feedback Studies for the 380 GeV CLIC Beam Delivery System

2683

R.M. Bodenstein, P. Burrows, J. Snuverink
JAI, Egham, Surrey, United Kingdom
F. Plassard
CERN, Geneva, Switzerland

In its currently-envisaged initial stage, the Compact Linear Collider (CLIC) will collide beams with a 380 GeV center of mass energy. To maintain the luminosity within a few percent of the design value, beam stability at the interaction point (IP) must be controlled at the sub-nanometer level. To help achieve such control, use of an intra-pulse IP feedback system is planned. With CLIC's very short bunch spacing of 0.5 ns, and nominal pulse duration of 176 ns, this feedback system presents a significant technical challenge. Furthermore, as part of a study to optimize the design of the beam delivery system (BDS), several L* configurations have been studied. In this paper, we will review the IP feedback simulations for the 380 GeV machine for two L* configurations, and compare luminosity recovery performance with that of the original L* configuration in the 3 TeV machine.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOR009

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THOAA02

The Development of C-Band Cavity Beam Position Monitor with a Position Resolution of Nano Meter

3149

S.W. Jang, E.-S. Kim
Korea University Sejong Campus, Sejong, Republic of Korea
P. Bambade, O.R. Blanco-García, S. Wallon
LAL, Orsay, France
N. Blaskovic Kraljevic, T. Bromwich, P. Burrows
JAI, Oxford, United Kingdom
T. Tauchi, N. Terunuma
KEK, Ibaraki, Japan

We developed and tested an C-band beam position monitor with position resolution of nano meter in ATF2. The C-band BPM was developed for the fast beam feedback system at the interaction point of ATF in KEK, which C-band beam position monitor called to IPBPM (Interaction Point Beam Position Monitor). The developed IPBPM was measured 26nm with 30% of nominal beam charge of ATF. From the measured beam position resolution, we can expected to 8nm beam position resolution with nominal ATF beam charge condition. In this talk, we will described about the development of IPBPM and the beam test results of nano meter level beam position resolution.

Slides THOAA02 [4.806 MB]

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THOAA02

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THPOR032

Effect and Optimisation of Non-Linear Chromatic Aberrations of the CLIC Drive Beam Recombination at CTF3

3852

D. Gamba, R. Corsini, P.K. Skowroński, F. Tecker
CERN, Geneva, Switzerland
P. Burrows
JAI, Oxford, United Kingdom
P. Burrows
Oxford University, Physics Department, Oxford, Oxon, United Kingdom

The CLIC design relies on the two-beam acceleration principle, i.e. the energy transfer from the so called drive beam to the main colliding beams. At the CLIC Test Facility (CTF3) at CERN the feasibility of this principle is being tested in terms of performance and achievable specifications. The high-current drive beam is generated by recombining its parts in a delay loop and a combiner ring. Preserving the drive beam emittance during the recombination process is crucial to ensure beam-current and power production stability. Present theoretical and experimental studies show that non-linear energy dependence of the transverse optics heavily spoils the quality of the recombined beam. Conventionally these effects are cured by means of non-linear corrections using sextupoles. In this work we propose a mitigation of these effects by optimising the linear lattice, leading to a more robust and easy to operate drive beam recombination complex. The latest results are presented.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR032

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THPOR034

Bunch-by-bunch Position and Angle Stabilisation at ATF based on Sub-micron Resolution Stripline Beam Position Monitors

3859

N. Blaskovic Kraljevic, R.M. Bodenstein, T. Bromwich, P. Burrows, G.B. Christian, M.R. Davis, C. Perry, R.L. Ramjiawan
JAI, Oxford, United Kingdom
D.R. Bett
CERN, Geneva, Switzerland

A low-latency, sub-micron resolution stripline beam position monitoring (BPM) system has been developed and tested with beam at the KEK Accelerator Test Facility (ATF2), where it has been used to drive a beam stabilisation system. The fast analogue front-end signal processor is based on a single-stage radio-frequency down-mixer, with a measured latency of 16 ns and a demonstrated single-pass beam position resolution of below 300 nm using a beam with a bunch charge of approximately 1 nC. The BPM position data are digitised on a digital feedback board which is used to drive a pair of kickers local to the BPMs and nominally orthogonal in phase in closed-loop feedback mode, thus achieving both beam position and angle stabilisation. We report the reduction in jitter as measured at a witness stripline BPM located 30 metres downstream of the feedback system and its propagation to the ATF interaction point.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR034

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THPOR035

Development of a Low-latency, Micrometre-level Precision, Intra-train Beam Feedback System based on Cavity Beam Position Monitors

3862

N. Blaskovic Kraljevic, R.M. Bodenstein, T. Bromwich, P. Burrows, G.B. Christian, M.R. Davis, C. Perry, R.L. Ramjiawan
JAI, Oxford, United Kingdom
D.R. Bett
CERN, Geneva, Switzerland

A low-latency, intra-train, beam feedback system utilising a cavity beam position monitor (BPM) has been developed and tested at the final focus of the Accelerator Test Facility (ATF2) at KEK. A low-Q cavity BPM was utilised with custom signal processing electronics, designed for low latency and optimal position resolution, to provide an input beam position signal to the feedback system. A custom stripline kicker and power amplifier, and a digital feedback board, were used to provide beam correction and feedback control, respectively. The system was deployed in single-pass, multi-bunch mode with the aim of demonstrating intra-train beam stabilisation on electron bunches of charge ~1 nC separated in time by c. 220 ns. The system has been used to demonstrate beam stabilisation to below the 75 nm level. Results of the latest beam tests, aimed at even higher performance, will be presented.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR035

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