IBIC2012 - List of Authors (Urakawa, J.)

Paper

Title

Page

Emittance Measurement using X-ray Beam Profile Monitor at KEK-ATF

215

T. Naito, H. Hayano, K. Kubo, S. Kuroda, N. Nakamura, T. Okugi, H. Sakai, N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan

The X-ray profile monitor (XPM) is used for the beam size measurement in the KEK-ATF damping ring(ATF-DR) at all times. The XPM consists of a crystal monochromator, two Fresnel zone plates(FZPs) and X-ray CCD camera. Two FZPs make the imaging optics. The design resolution of the selected wavelength 3.8nm is less than 1μm, which is sufficiently small for the emittance measurement of the ATF-DR. However, the measured results at the early stage were affected by the mechanical vibration. This paper describes the improvement of the resolution and the measurement results.

TUCC04

Measurement of Nanometer Electron Beam Sizes with Laser Interference using IPBSM

310

J.N. Yan, S. Komamiya, M. Oroku, T.S. Suehara, Y. Yamaguchi, T. Yamanaka
University of Tokyo, Tokyo, Japan
S. Araki, T. Okugi, T. Tauchi, N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan
Y. Kamiya
ICEPP, Tokyo, Japan

At ATF2, the Local Chromaticity Correction focusing scheme is to be verified through realizing its design vertical e^- beam size (σy ) of 37 nm. The 'IPBSM', installed at ATF2's virtual IP, is the only existing beam size monitor capable of measuring σy < 100 nm, making it indispensable for ATF's goals and R&D at future LCs. This owes to a novel technique of colliding e^- beam against laser interference fringes. σy is derived from the modulation depth of resulting Compton photons, which is large for small σy. The measurable range from O(10) nm ~ a few μm, is controlled by switching between laser crossing angles θ = 174° , 30°, and 2° - 8° . In early 2011, measuring σy < 300 nm was hindered by an immense earthquake and heavy signal jitters. The ensuing recovery and upgrades stabilized the laser system and improved resolution to 5%. In spring 2012, we commissioned advanced crossing angle modes by consistently measuring σy ≥ 150 nm. Our goals for the autumn 2012 run is to stably measure σy < 50 nm. Major hardware upgrades during the summer aim at more reliable alignment and optimization of specialized functions to suppress bias factors.

Slides TUCC04 [10.535 MB]

WECA01

Theoretical and Experimental Investigation on Resolution of Optical Transition Radiation Transverse Beam Profile Monitor

A.S. Aryshev, N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan
B. Bolzon, E. Bravin, T. Lefèvre
CERN, Geneva, Switzerland
S.T. Boogert, V. Karataev
Royal Holloway, University of London, Surrey, United Kingdom
L.J. Nevay
Oxford University, Physics Department, Oxford, Oxon, United Kingdom

Optical Transition Radiation (OTR) appearing when a charged particle crosses an interface between two media with different dielectric constants has widely been used as a tool for transverse profile measurements of charged particle beams in numerous facilities worldwide. The basic tuning methods and operation of conventional OTR monitors are well established for transverse beam sizes not smaller than 3-5 um. Since the Point Spread Function (PSF) dimension defines the resolution of the conventional monitors, for small electron beam dimensions the PSF form significantly depends on a presence of OTR tails diffraction and aberrations in the optical system. In our experiment we have managed to squeeze the electron beam such that we can practically measure PSF distribution in one direction. The revealed PSF structure is such that the visibility depends on the transverse beam size on micron scale. We developed an empirical calibration technique and successfully overcame the resolution limit of the common OTR monitor reaching sub-micron level. Here we represent the recent developments and upgrades in both setup and data analysis of a sub-micrometer electron beam profile monitor.

Slides WECA01 [2.230 MB]

Paper	Title	Page
MOPB63	Emittance Measurement using X-ray Beam Profile Monitor at KEK-ATF	215
	T. Naito, H. Hayano, K. Kubo, S. Kuroda, N. Nakamura, T. Okugi, H. Sakai, N. Terunuma, J. Urakawa KEK, Ibaraki, Japan
	The X-ray profile monitor (XPM) is used for the beam size measurement in the KEK-ATF damping ring(ATF-DR) at all times. The XPM consists of a crystal monochromator, two Fresnel zone plates(FZPs) and X-ray CCD camera. Two FZPs make the imaging optics. The design resolution of the selected wavelength 3.8nm is less than 1μm, which is sufficiently small for the emittance measurement of the ATF-DR. However, the measured results at the early stage were affected by the mechanical vibration. This paper describes the improvement of the resolution and the measurement results.

TUCC04	Measurement of Nanometer Electron Beam Sizes with Laser Interference using IPBSM	310
	J.N. Yan, S. Komamiya, M. Oroku, T.S. Suehara, Y. Yamaguchi, T. Yamanaka University of Tokyo, Tokyo, Japan S. Araki, T. Okugi, T. Tauchi, N. Terunuma, J. Urakawa KEK, Ibaraki, Japan Y. Kamiya ICEPP, Tokyo, Japan
	At ATF2, the Local Chromaticity Correction focusing scheme is to be verified through realizing its design vertical e^- beam size (σy ) of 37 nm. The 'IPBSM', installed at ATF2's virtual IP, is the only existing beam size monitor capable of measuring σy < 100 nm, making it indispensable for ATF's goals and R&D at future LCs. This owes to a novel technique of colliding e^- beam against laser interference fringes. σy is derived from the modulation depth of resulting Compton photons, which is large for small σy. The measurable range from O(10) nm ~ a few μm, is controlled by switching between laser crossing angles θ = 174° , 30°, and 2° - 8° . In early 2011, measuring σy < 300 nm was hindered by an immense earthquake and heavy signal jitters. The ensuing recovery and upgrades stabilized the laser system and improved resolution to 5%. In spring 2012, we commissioned advanced crossing angle modes by consistently measuring σy ≥ 150 nm. Our goals for the autumn 2012 run is to stably measure σy < 50 nm. Major hardware upgrades during the summer aim at more reliable alignment and optimization of specialized functions to suppress bias factors.
	Slides TUCC04 [10.535 MB]

WECA01	Theoretical and Experimental Investigation on Resolution of Optical Transition Radiation Transverse Beam Profile Monitor
	A.S. Aryshev, N. Terunuma, J. Urakawa KEK, Ibaraki, Japan B. Bolzon, E. Bravin, T. Lefèvre CERN, Geneva, Switzerland S.T. Boogert, V. Karataev Royal Holloway, University of London, Surrey, United Kingdom L.J. Nevay Oxford University, Physics Department, Oxford, Oxon, United Kingdom
	Optical Transition Radiation (OTR) appearing when a charged particle crosses an interface between two media with different dielectric constants has widely been used as a tool for transverse profile measurements of charged particle beams in numerous facilities worldwide. The basic tuning methods and operation of conventional OTR monitors are well established for transverse beam sizes not smaller than 3-5 um. Since the Point Spread Function (PSF) dimension defines the resolution of the conventional monitors, for small electron beam dimensions the PSF form significantly depends on a presence of OTR tails diffraction and aberrations in the optical system. In our experiment we have managed to squeeze the electron beam such that we can practically measure PSF distribution in one direction. The revealed PSF structure is such that the visibility depends on the transverse beam size on micron scale. We developed an empirical calibration technique and successfully overcame the resolution limit of the common OTR monitor reaching sub-micron level. Here we represent the recent developments and upgrades in both setup and data analysis of a sub-micrometer electron beam profile monitor.
	Slides WECA01 [2.230 MB]