IPAC2019 - List of Authors (Burrows, P.)

Paper	Title	Page
MOPGW081	Measurements of Stray Magnetic Fields at CERN for CLIC	289
SUSPFO099	use link to see paper's listing under its alternate paper code
	C. Gohil, N. Blaskovic Kraljevic, D. Schulte CERN, Meyrin, Switzerland P. Burrows JAI, Oxford, United Kingdom B. Heilig MFGI, Budapest, Hungary
	Simulations have shown that the Compact Linear Collider (CLIC) is sensitive to external dynamic magnetic fields (stray fields) to the nT level. Magnetic fields are not typically measured to this precision at CERN. Past measurements of the background magnetic field at CERN are limited. In this paper new measurements are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW081
About •	paper received ※ 01 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPGW082	Mitigation of Stray Magnetic Field Effects in CLIC with Passive Shielding	293
	C. Gohil, N. Blaskovic Kraljevic, D. Schulte CERN, Meyrin, Switzerland P. Burrows JAI, Oxford, United Kingdom
	Simulations have shown the Compact Linear Collider (CLIC) is sensitive to external dynamic magnetic fields (stray fields) to the nT level. Due to these extremely tight tolerances, mitigation techniques will be required to prevent performance loss. A passive shielding technique is envisaged as a potential solution. A model for passive shielding is presented along with calculations of its transfer function. Measurements of the transfer function of a promising material (mu-metal) that can be used for passive shielding are presented. The validity of passive shielding models in small amplitude magnetic fields is also discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW082
About •	paper received ※ 01 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMP038	Investigation of CLIC 380 GeV Post-Collision Line	528
	R.M. Bodenstein, A. Abramov, S.T. Boogert, P. Burrows, L.J. Nevay JAI, Egham, Surrey, United Kingdom D. Schulte, R. Tomás CERN, Geneva, Switzerland
	It has been proposed that the Compact Linear Collider (CLIC) be commissioned in stages, starting with a lower-energy, 380 GeV version for the first stage, and concluding with a 3 TeV version for the final stage. In the Conceptual Design Report (CDR) published in 2012, the post-collision line is described for the 3 TeV and 500 GeV stages. However, the post-collision line for the 380 GeV design was not investigated. This work will describe the simulation studies performed in BDSIM for the 380 GeV post-collision line.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP038
About •	paper received ※ 13 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPGW092	Nanosecond-Latency Sub-Micron Resolution Stripline Beam Position Monitor Signal Processor for CLIC	2705
SUSPFO118	use link to see paper's listing under its alternate paper code
	R.L. Ramjiawan, D.R. Bett, P. Burrows, G.B. Christian, C. Perry JAI, Oxford, United Kingdom
	A high-resolution, low-latency stripline beam position monitor (BPM) signal processor has been developed for use in an intra-train feedback system for the Compact Linear Collider (CLIC). The processor was designed to have extremely low latency of order nanoseconds and a target position resolution of order 1 micron. The processor consists of a pair of diodes to form the difference and sum of a pair of stripline BPM inputs with microstrip filters to reduce out-of-band noise. The assembled prototype was optimized for use with the electron beam in the extraction line of the Accelerator Test Facility at the High Energy Accelerator Research Organization (KEK) in Japan but the underlying design is readily scaleable to a higher frequency response relevant for CLIC. A latency of 3 ns was measured in a testbench setup. We report the results of performance tests with beam in which the position resolution was measured to be c. 325 nm.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW092
About •	paper received ※ 15 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPRB062	Spatially Resolved Dark Current in High Gradient Traveling Wave Structures	2956
SUSPFO106	use link to see paper's listing under its alternate paper code
	J. Paszkiewicz, W. Wuensch CERN, Meyrin, Switzerland P. Burrows JAI, Oxford, United Kingdom P. Burrows Oxford University, Physics Department, Oxford, Oxon, United Kingdom
	High-gradient accelerating structures are known to produce field-emitted current from regions of high surface field, which are captured and accelerated by the fields within the structure. This current is routinely measured in structures under test in the CLIC high-gradient test stands using Faraday cups. This paper presents a novel technique to spatially resolve the longitudinal distribution of field emitted current by analysing downstream Faraday cup signals when the structure is fed with RF pulses much shorter than its filling time. Results from this method applied to X-band cavities operating at 100 MV/m are presented, and are compared to breakdown position distributions. A decay in emitted current as conditioning progressed in regions with a low breakdown rate and large jumps in regions with a large breakdown rate are observed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB062
About •	paper received ※ 29 April 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB096	Real-Time Beam Orbit Stabilisation to 200 Nanometres in Single-Pass Mode Using a High-Precision Dual-Phase Feedback System	4049
	D.R. Bett, P. Burrows, G.B. Christian, C. Perry, R.L. Ramjiawan JAI, Oxford, United Kingdom
	A high-resolution, low-latency, stripline beam position monitor (BPM) system has been developed for use at particle accelerators and beamlines that operate with trains of particle bunches with bunch separations as low as several tens of nanoseconds, such as future linear electron-positron colliders and free-electron lasers. The system consists of fast analogue stripline BPM signal processors input to a custom FPGA-based digital feedback board which drives 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. The feedback system was tested with the electron beam in the extraction line of the Accelerator Test Facility at the High Energy Accelerator Research Organization (KEK) in Japan. Recent upgrades to the BPMs have increased the single-shot, real-time position resolution of the system to ~150 nm for a beam charge of 1.3 nC. We report the latest results which demonstrate the feedback system operating at this resolution limit and a beam stabilisation performance of 200 nm.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB096
About •	paper received ※ 13 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPGW085	Intensity Dependent Effects in the ILC BDS	305
	P. Korysko, A. Latina CERN, Geneva, Switzerland P. Burrows Oxford University, Physics Department, Oxford, Oxon, United Kingdom
	The International Linear Collider (ILC) is an electron-positron collider being considered for the post-LHC era. Its Beam Delivery System (BDS) receives the beam from the main linac. This beam is then focused to the nanometer scale after going through collimators, beam diagnostic systems, strong magnets, etc. Effects such as wakefields due to resistive-wall, BPMs and collimators make the system very sensitive to the beam intensity. Understanding these effects is crucial in order to demonstrate that the nominal beam size at the Interaction Point (IP) can be reached in realistic scenarios. In this paper, results of the intensity dependence effects in the ILC BDS, simulated with PLACET, are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW085
About •	paper received ※ 23 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPGW086	Intensity Dependent Effects at ATF2, KEK	308
SUSPFO104	use link to see paper's listing under its alternate paper code
	P. Korysko, A. Latina CERN, Geneva, Switzerland P. Burrows Oxford University, Physics Department, Oxford, Oxon, United Kingdom A. Faus-Golfe LAL, Orsay, France K. Kubo, T. Okugi KEK, Ibaraki, Japan
	The Accelerator Test Facility 2 (ATF2) at KEK is a prototype for the Final Focus Systems of the future e⁺e⁻ linear colliders, the International Linear Collider (ILC) and the Compact Linear Collider (CLIC). In this paper both simulation and experimental results are presented with special emphasis on intensity-dependent effects. The importance of these effects is shown using the PLACET code and realistic ATF2 machine simulations (including beam jitter, misalignment, wakefield, Beam Based Alignment (BBA) correction, …). The latest experimental results are also presented, in particular the impact of the beam intensity on the beam size at the IP.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW086
About •	paper received ※ 23 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

MOPGW081

Measurements of Stray Magnetic Fields at CERN for CLIC

289

SUSPFO099

use link to see paper's listing under its alternate paper code

C. Gohil, N. Blaskovic Kraljevic, D. Schulte
CERN, Meyrin, Switzerland
P. Burrows
JAI, Oxford, United Kingdom
B. Heilig
MFGI, Budapest, Hungary

Simulations have shown that the Compact Linear Collider (CLIC) is sensitive to external dynamic magnetic fields (stray fields) to the nT level. Magnetic fields are not typically measured to this precision at CERN. Past measurements of the background magnetic field at CERN are limited. In this paper new measurements are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW081

About •

paper received ※ 01 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPGW082

Mitigation of Stray Magnetic Field Effects in CLIC with Passive Shielding

293

C. Gohil, N. Blaskovic Kraljevic, D. Schulte
CERN, Meyrin, Switzerland
P. Burrows
JAI, Oxford, United Kingdom

Simulations have shown the Compact Linear Collider (CLIC) is sensitive to external dynamic magnetic fields (stray fields) to the nT level. Due to these extremely tight tolerances, mitigation techniques will be required to prevent performance loss. A passive shielding technique is envisaged as a potential solution. A model for passive shielding is presented along with calculations of its transfer function. Measurements of the transfer function of a promising material (mu-metal) that can be used for passive shielding are presented. The validity of passive shielding models in small amplitude magnetic fields is also discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW082

About •

paper received ※ 01 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPMP038

Investigation of CLIC 380 GeV Post-Collision Line

528

R.M. Bodenstein, A. Abramov, S.T. Boogert, P. Burrows, L.J. Nevay
JAI, Egham, Surrey, United Kingdom
D. Schulte, R. Tomás
CERN, Geneva, Switzerland

It has been proposed that the Compact Linear Collider (CLIC) be commissioned in stages, starting with a lower-energy, 380 GeV version for the first stage, and concluding with a 3 TeV version for the final stage. In the Conceptual Design Report (CDR) published in 2012, the post-collision line is described for the 3 TeV and 500 GeV stages. However, the post-collision line for the 380 GeV design was not investigated. This work will describe the simulation studies performed in BDSIM for the 380 GeV post-collision line.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP038

About •

paper received ※ 13 May 2019 paper accepted ※ 18 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPGW092

Nanosecond-Latency Sub-Micron Resolution Stripline Beam Position Monitor Signal Processor for CLIC

2705

SUSPFO118

use link to see paper's listing under its alternate paper code

R.L. Ramjiawan, D.R. Bett, P. Burrows, G.B. Christian, C. Perry
JAI, Oxford, United Kingdom

A high-resolution, low-latency stripline beam position monitor (BPM) signal processor has been developed for use in an intra-train feedback system for the Compact Linear Collider (CLIC). The processor was designed to have extremely low latency of order nanoseconds and a target position resolution of order 1 micron. The processor consists of a pair of diodes to form the difference and sum of a pair of stripline BPM inputs with microstrip filters to reduce out-of-band noise. The assembled prototype was optimized for use with the electron beam in the extraction line of the Accelerator Test Facility at the High Energy Accelerator Research Organization (KEK) in Japan but the underlying design is readily scaleable to a higher frequency response relevant for CLIC. A latency of 3 ns was measured in a testbench setup. We report the results of performance tests with beam in which the position resolution was measured to be c. 325 nm.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW092

About •

paper received ※ 15 May 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPRB062

Spatially Resolved Dark Current in High Gradient Traveling Wave Structures

2956

SUSPFO106

use link to see paper's listing under its alternate paper code

J. Paszkiewicz, W. Wuensch
CERN, Meyrin, Switzerland
P. Burrows
JAI, Oxford, United Kingdom
P. Burrows
Oxford University, Physics Department, Oxford, Oxon, United Kingdom

High-gradient accelerating structures are known to produce field-emitted current from regions of high surface field, which are captured and accelerated by the fields within the structure. This current is routinely measured in structures under test in the CLIC high-gradient test stands using Faraday cups. This paper presents a novel technique to spatially resolve the longitudinal distribution of field emitted current by analysing downstream Faraday cup signals when the structure is fed with RF pulses much shorter than its filling time. Results from this method applied to X-band cavities operating at 100 MV/m are presented, and are compared to breakdown position distributions. A decay in emitted current as conditioning progressed in regions with a low breakdown rate and large jumps in regions with a large breakdown rate are observed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB062

About •

paper received ※ 29 April 2019 paper accepted ※ 21 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRB096

Real-Time Beam Orbit Stabilisation to 200 Nanometres in Single-Pass Mode Using a High-Precision Dual-Phase Feedback System

4049

D.R. Bett, P. Burrows, G.B. Christian, C. Perry, R.L. Ramjiawan
JAI, Oxford, United Kingdom

A high-resolution, low-latency, stripline beam position monitor (BPM) system has been developed for use at particle accelerators and beamlines that operate with trains of particle bunches with bunch separations as low as several tens of nanoseconds, such as future linear electron-positron colliders and free-electron lasers. The system consists of fast analogue stripline BPM signal processors input to a custom FPGA-based digital feedback board which drives 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. The feedback system was tested with the electron beam in the extraction line of the Accelerator Test Facility at the High Energy Accelerator Research Organization (KEK) in Japan. Recent upgrades to the BPMs have increased the single-shot, real-time position resolution of the system to ~150 nm for a beam charge of 1.3 nC. We report the latest results which demonstrate the feedback system operating at this resolution limit and a beam stabilisation performance of 200 nm.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB096

About •

paper received ※ 13 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPGW085

Intensity Dependent Effects in the ILC BDS

305

P. Korysko, A. Latina
CERN, Geneva, Switzerland
P. Burrows
Oxford University, Physics Department, Oxford, Oxon, United Kingdom

The International Linear Collider (ILC) is an electron-positron collider being considered for the post-LHC era. Its Beam Delivery System (BDS) receives the beam from the main linac. This beam is then focused to the nanometer scale after going through collimators, beam diagnostic systems, strong magnets, etc. Effects such as wakefields due to resistive-wall, BPMs and collimators make the system very sensitive to the beam intensity. Understanding these effects is crucial in order to demonstrate that the nominal beam size at the Interaction Point (IP) can be reached in realistic scenarios. In this paper, results of the intensity dependence effects in the ILC BDS, simulated with PLACET, are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW085

About •

paper received ※ 23 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPGW086

Intensity Dependent Effects at ATF2, KEK

308

SUSPFO104

use link to see paper's listing under its alternate paper code

P. Korysko, A. Latina
CERN, Geneva, Switzerland
P. Burrows
Oxford University, Physics Department, Oxford, Oxon, United Kingdom
A. Faus-Golfe
LAL, Orsay, France
K. Kubo, T. Okugi
KEK, Ibaraki, Japan

The Accelerator Test Facility 2 (ATF2) at KEK is a prototype for the Final Focus Systems of the future e⁺e⁻ linear colliders, the International Linear Collider (ILC) and the Compact Linear Collider (CLIC). In this paper both simulation and experimental results are presented with special emphasis on intensity-dependent effects. The importance of these effects is shown using the PLACET code and realistic ATF2 machine simulations (including beam jitter, misalignment, wakefield, Beam Based Alignment (BBA) correction, …). The latest experimental results are also presented, in particular the impact of the beam intensity on the beam size at the IP.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW086

About •

paper received ※ 23 April 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)