IBIC2016 - List of Authors (Mitsuhashi, T.M.)

Paper	Title	Page
MOPG70	Transverse Beam Profiling and Vertical Emittance Control with a Double-Slit Stellar Interferometer	236
	W.J. Corbett, X. Huang, J. Wu SLAC, Menlo Park, California, USA C.L. Li, W.J. Zhang East China University of Science and Technology, Shanghai, People's Republic of China T.M. Mitsuhashi KEK, Ibaraki, Japan Y.H. Xu DongHua University, Songjiang, People's Republic of China W.J. Zhang University of Saskatchewan, Saskatoon, Canada
	Double-slit interferometers are useful tools to measure the transverse the cross-section of relativistic charged particle beams emitting incoherent synchrotron radiation. By rotating the double-slit about the beam propagation axis, the transverse beam profile can be reconstructed including beam tilt at the source. The interferometer can also be used as a sensitive monitor for vertical emittance control. In this paper we outline a simple derivation of the Van Cittert-Zernike theorem, present results for a rotating double-slit measurement and demonstrate application of the interferometer to vertical emittance control using the Robust Conjugate Direction Search (RCDS) optimization algorithm.
	Poster MOPG70 [1.362 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-MOPG70
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MOPG74	Design and Performance of Coronagraph for Beam Halo Measurements in the LHC	253
	A. Goldblatt, E. Bravin, F. Roncarolo, G. Trad CERN, Geneva, Switzerland T.M. Mitsuhashi KEK, Ibaraki, Japan
	The CERN Large Hadron Collider is equipped with two Beam Synchrotron Radiation (BSR) systems, one per beam, used to monitor the transverse distribution of the beam, its longitudinal distribution and the abort gap population. During the 2015-2016 winter shut-down period, one of the two BSR systems was equipped with a prototype beam halo monitor, based on the coronagraph technique, classically used in astrophysics telescopes to measure the sun corona. The system design, as well as its optics, was inherited from the coronagraph used in the KEK Photon Factory with some modifications made in order to satisfy the LHC BSR source constraints. This project is in the framework of the HL-LHC project, for which there is the requirement to monitor the beam halo at the level of 10^-6 of the core intensity. This first prototype has been designed as a demonstrator system aimed at resolving a halo-core contrast in the 10-3 to 10-4 range. After discussing the design of the LHC coronagraph and its technical implementation, this contribution presents the result of the first tests with beam and the planned system upgrades for 2017.
	Poster MOPG74 [1.671 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-MOPG74
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEBL02	Beam Size Measurements Using Interferometry at LHC	583
	G. Trad, E. Bravin, A. Goldblatt, S. Mazzoni, F. Roncarolo CERN, Geneva, Switzerland T.M. Mitsuhashi KEK, Ibaraki, Japan
	During the long LHC shutdown 2013-2014, both the LHC and its injector chain underwent significant upgrades. The most important changes concerned increasing the maximum LHC beam energy from 4TeV to 6.5TeV and reducing the transverse emittance of the beam from the LHC injectors. These upgrades pose challenges to the measurement of the transverse beam size via Synchrotron Radiation (SR) imaging, as the radiation parameters approach the diffraction limit. Optical SR interferometry, widely used in synchrotron light facilities, was considered as an alternative method to measure the 150 'm rms beam size at top energy as it allows measurements below the diffraction limit. A system based on this technique was therefore implemented in the LHC, for the first time on a proton machine. This paper describes the design of the LHC interferometer and its two SR sources (a superconducting undulator at low energy and a bending dipole at high energy), along with the expected performance in terms of beam size measurement as compared to the imaging system. The world's first proton beam interferogram measured at the LHC will be shown and plans to make this an operational monitor will be presented.
	Slides WEBL02 [42.662 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-WEBL02
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Transverse Beam Profiling and Vertical Emittance Control with a Double-Slit Stellar Interferometer

236

W.J. Corbett, X. Huang, J. Wu
SLAC, Menlo Park, California, USA
C.L. Li, W.J. Zhang
East China University of Science and Technology, Shanghai, People's Republic of China
T.M. Mitsuhashi
KEK, Ibaraki, Japan
Y.H. Xu
DongHua University, Songjiang, People's Republic of China
W.J. Zhang
University of Saskatchewan, Saskatoon, Canada

Double-slit interferometers are useful tools to measure the transverse the cross-section of relativistic charged particle beams emitting incoherent synchrotron radiation. By rotating the double-slit about the beam propagation axis, the transverse beam profile can be reconstructed including beam tilt at the source. The interferometer can also be used as a sensitive monitor for vertical emittance control. In this paper we outline a simple derivation of the Van Cittert-Zernike theorem, present results for a rotating double-slit measurement and demonstrate application of the interferometer to vertical emittance control using the Robust Conjugate Direction Search (RCDS) optimization algorithm.

Poster MOPG70 [1.362 MB]

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-MOPG70

Export •

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

MOPG74

Design and Performance of Coronagraph for Beam Halo Measurements in the LHC

253

A. Goldblatt, E. Bravin, F. Roncarolo, G. Trad
CERN, Geneva, Switzerland
T.M. Mitsuhashi
KEK, Ibaraki, Japan

The CERN Large Hadron Collider is equipped with two Beam Synchrotron Radiation (BSR) systems, one per beam, used to monitor the transverse distribution of the beam, its longitudinal distribution and the abort gap population. During the 2015-2016 winter shut-down period, one of the two BSR systems was equipped with a prototype beam halo monitor, based on the coronagraph technique, classically used in astrophysics telescopes to measure the sun corona. The system design, as well as its optics, was inherited from the coronagraph used in the KEK Photon Factory with some modifications made in order to satisfy the LHC BSR source constraints. This project is in the framework of the HL-LHC project, for which there is the requirement to monitor the beam halo at the level of 10^-6 of the core intensity. This first prototype has been designed as a demonstrator system aimed at resolving a halo-core contrast in the 10-3 to 10-4 range. After discussing the design of the LHC coronagraph and its technical implementation, this contribution presents the result of the first tests with beam and the planned system upgrades for 2017.

Poster MOPG74 [1.671 MB]

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-MOPG74

Export •

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

WEBL02

Beam Size Measurements Using Interferometry at LHC

583

G. Trad, E. Bravin, A. Goldblatt, S. Mazzoni, F. Roncarolo
CERN, Geneva, Switzerland
T.M. Mitsuhashi
KEK, Ibaraki, Japan

During the long LHC shutdown 2013-2014, both the LHC and its injector chain underwent significant upgrades. The most important changes concerned increasing the maximum LHC beam energy from 4TeV to 6.5TeV and reducing the transverse emittance of the beam from the LHC injectors. These upgrades pose challenges to the measurement of the transverse beam size via Synchrotron Radiation (SR) imaging, as the radiation parameters approach the diffraction limit. Optical SR interferometry, widely used in synchrotron light facilities, was considered as an alternative method to measure the 150 'm rms beam size at top energy as it allows measurements below the diffraction limit. A system based on this technique was therefore implemented in the LHC, for the first time on a proton machine. This paper describes the design of the LHC interferometer and its two SR sources (a superconducting undulator at low energy and a bending dipole at high energy), along with the expected performance in terms of beam size measurement as compared to the imaging system. The world's first proton beam interferogram measured at the LHC will be shown and plans to make this an operational monitor will be presented.

Slides WEBL02 [42.662 MB]

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IBIC2016-WEBL02

Export •

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