IBIC2019 - List of Authors (Gibson, S.M.)

Paper	Title	Page
WEAO04	Beam Measurements at the CERN SPS Using Interferometric Electro-Optic Pickups	457
	A. Arteche, A. Bosco, S.M. Gibson Royal Holloway, University of London, Surrey, United Kingdom S.E. Bashforth, A. Bosco, S.M. Gibson JAI, Egham, Surrey, United Kingdom M. Krupa, T. Lefèvre CERN, Geneva, Switzerland
	Funding: Work supported by UK STFC grants ST/N001583/1, JAI at Royal Holloway University of London and CERN. Since 2016 a prototype electro-optic pickup has been installed on the SPS as part of the ongoing development of a high bandwidth electro-optic beam position monitor for the High Luminosity LHC. Following the success of initial beam signal observations with the prototype, improvements of the sensitivity and stability of the pickup have become the main focus of the project. A new concept has been developed which uses an interferometric technique to measure the image field of a passing bunch. One arm of an interferometer passes through an electro-optic lithium niobate crystal, embedded in a pickup, whereas the other arm bypasses. The recombination after the pickup results in an interference pattern that changes as a bunch passes by, due to the electro-optic response of the crystal to the image field. This technique enhances the sensitivity to the field and improves control of the working point. Results from high intensity beams at the SPS are presented. These include a comparison between two different interferometric configurations that were tested on different pickups with similar beam conditions. The stability is assessed by frequency scanning interferometry during beam operation.
	Slides WEAO04 [52.252 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-WEAO04
About •	paper received ※ 10 September 2019 paper accepted ※ 12 September 2019 issue date ※ 10 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUBO04	Measuring the Beam Profile by Counting Ionization Electrons	257
	H.S. Sandberg, W. Bertsche UMAN, Manchester, United Kingdom D. Bodart, B. Dehning, S. Levasseur, H.S. Sandberg, G. Schneider, J.W. Storey, R. Veness CERN, Geneva, Switzerland S.M. Gibson Royal Holloway, University of London, Surrey, United Kingdom K. Satou J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	The principle of non-destructive beam profile measurement with rest gas ionization electrons has remained largely unchanged since the technique was first proposed in the late 1960¿s. Ionization electrons (or ions) are transported by an electrostatic field onto an imaging detector, where the spatial distribution of detected electrons is a direct measure of the transverse beam profile. The detector typically consists of one or more Micro-Channel Plates (MCP’s) to amplify the signal, followed by either a phosphor screen and camera, or pickup electrodes. A long-standing problem is the ageing of the MCP’s, which limits the accuracy of the beam profile measurement. A new technique to detect ionization electrons has been developed at CERN, which uses a hybrid pixel detector to detect single ionisation electrons. This allows the application of counting statistics to the beam profile measurement. It will be shown that a meaningful beam profile can be extracted from only 100 electrons. Results from the new instrument will be presented, which demonstrate the ability to measure the beam profile of single bunches turn-by-turn, which offers new opportunities for beam diagnostic insights.
	Slides TUBO04 [2.199 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-TUBO04
About •	paper received ※ 03 September 2019 paper accepted ※ 08 September 2019 issue date ※ 10 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Beam Measurements at the CERN SPS Using Interferometric Electro-Optic Pickups

457

A. Arteche, A. Bosco, S.M. Gibson
Royal Holloway, University of London, Surrey, United Kingdom
S.E. Bashforth, A. Bosco, S.M. Gibson
JAI, Egham, Surrey, United Kingdom
M. Krupa, T. Lefèvre
CERN, Geneva, Switzerland

Funding: Work supported by UK STFC grants ST/N001583/1, JAI at Royal Holloway University of London and CERN.
Since 2016 a prototype electro-optic pickup has been installed on the SPS as part of the ongoing development of a high bandwidth electro-optic beam position monitor for the High Luminosity LHC. Following the success of initial beam signal observations with the prototype, improvements of the sensitivity and stability of the pickup have become the main focus of the project. A new concept has been developed which uses an interferometric technique to measure the image field of a passing bunch. One arm of an interferometer passes through an electro-optic lithium niobate crystal, embedded in a pickup, whereas the other arm bypasses. The recombination after the pickup results in an interference pattern that changes as a bunch passes by, due to the electro-optic response of the crystal to the image field. This technique enhances the sensitivity to the field and improves control of the working point. Results from high intensity beams at the SPS are presented. These include a comparison between two different interferometric configurations that were tested on different pickups with similar beam conditions. The stability is assessed by frequency scanning interferometry during beam operation.

Slides WEAO04 [52.252 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-WEAO04

About •

paper received ※ 10 September 2019 paper accepted ※ 12 September 2019 issue date ※ 10 November 2019

Export •

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

TUBO04

Measuring the Beam Profile by Counting Ionization Electrons

257

H.S. Sandberg, W. Bertsche
UMAN, Manchester, United Kingdom
D. Bodart, B. Dehning, S. Levasseur, H.S. Sandberg, G. Schneider, J.W. Storey, R. Veness
CERN, Geneva, Switzerland
S.M. Gibson
Royal Holloway, University of London, Surrey, United Kingdom
K. Satou
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

The principle of non-destructive beam profile measurement with rest gas ionization electrons has remained largely unchanged since the technique was first proposed in the late 1960¿s. Ionization electrons (or ions) are transported by an electrostatic field onto an imaging detector, where the spatial distribution of detected electrons is a direct measure of the transverse beam profile. The detector typically consists of one or more Micro-Channel Plates (MCP’s) to amplify the signal, followed by either a phosphor screen and camera, or pickup electrodes. A long-standing problem is the ageing of the MCP’s, which limits the accuracy of the beam profile measurement. A new technique to detect ionization electrons has been developed at CERN, which uses a hybrid pixel detector to detect single ionisation electrons. This allows the application of counting statistics to the beam profile measurement. It will be shown that a meaningful beam profile can be extracted from only 100 electrons. Results from the new instrument will be presented, which demonstrate the ability to measure the beam profile of single bunches turn-by-turn, which offers new opportunities for beam diagnostic insights.

Slides TUBO04 [2.199 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-TUBO04

About •

paper received ※ 03 September 2019 paper accepted ※ 08 September 2019 issue date ※ 10 November 2019

Export •

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