skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: A Laser-Wire System at the ATF Extraction Line

Abstract

A new laser-wire (LW) system has been installed at the ATF extraction line at KEK, Tsukuba. The system aims at a micron-scale laser spot size and employs a mode-locked laser system. The purpose-built interaction chamber, light delivery optics, and lens systems are described, and the first results are presented.

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more »; ; ; ; ; « less
Publication Date:
Research Org.:
Stanford Linear Accelerator Center (SLAC)
Sponsoring Org.:
USDOE
OSTI Identifier:
899568
Report Number(s):
SLAC-PUB-12328
TRN: US0701981
DOE Contract Number:
AC02-76SF00515
Resource Type:
Conference
Resource Relation:
Conference: Prepared for European Particle Accelerator Conference (EPAC 06), Edinburgh, Scotland, 26-30 Jun 2006
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; ACCELERATORS; LASERS; OPTICS; Accelerators,ACCPHY

Citation Formats

Boogert, S.T., Blair, G., Boorman, G., Bosco, A., Deacon, L., Driouichi, C., Karataev, P., /Royal Holloway, U. of London, Kamps, T., /BESSY, Berlin, Delerue, N., Dixit, S., Foster, B., Gannaway, F., Howell, D.F., Qureshi, M., Reichold, A., Senanayake, R., /Oxford U., Aryshev, A., Hayano, H., Kubo, K., Terunuma, N., Urakawa, J., and /KEK, Tsukuba /Liverpool U. /Cockcroft Inst. Accel. Sci. Tech. /SLAC. A Laser-Wire System at the ATF Extraction Line. United States: N. p., 2007. Web.
Boogert, S.T., Blair, G., Boorman, G., Bosco, A., Deacon, L., Driouichi, C., Karataev, P., /Royal Holloway, U. of London, Kamps, T., /BESSY, Berlin, Delerue, N., Dixit, S., Foster, B., Gannaway, F., Howell, D.F., Qureshi, M., Reichold, A., Senanayake, R., /Oxford U., Aryshev, A., Hayano, H., Kubo, K., Terunuma, N., Urakawa, J., & /KEK, Tsukuba /Liverpool U. /Cockcroft Inst. Accel. Sci. Tech. /SLAC. A Laser-Wire System at the ATF Extraction Line. United States.
Boogert, S.T., Blair, G., Boorman, G., Bosco, A., Deacon, L., Driouichi, C., Karataev, P., /Royal Holloway, U. of London, Kamps, T., /BESSY, Berlin, Delerue, N., Dixit, S., Foster, B., Gannaway, F., Howell, D.F., Qureshi, M., Reichold, A., Senanayake, R., /Oxford U., Aryshev, A., Hayano, H., Kubo, K., Terunuma, N., Urakawa, J., and /KEK, Tsukuba /Liverpool U. /Cockcroft Inst. Accel. Sci. Tech. /SLAC. Mon . "A Laser-Wire System at the ATF Extraction Line". United States. doi:. https://www.osti.gov/servlets/purl/899568.
@article{osti_899568,
title = {A Laser-Wire System at the ATF Extraction Line},
author = {Boogert, S.T. and Blair, G. and Boorman, G. and Bosco, A. and Deacon, L. and Driouichi, C. and Karataev, P. and /Royal Holloway, U. of London and Kamps, T. and /BESSY, Berlin and Delerue, N. and Dixit, S. and Foster, B. and Gannaway, F. and Howell, D.F. and Qureshi, M. and Reichold, A. and Senanayake, R. and /Oxford U. and Aryshev, A. and Hayano, H. and Kubo, K. and Terunuma, N. and Urakawa, J. and /KEK, Tsukuba /Liverpool U. /Cockcroft Inst. Accel. Sci. Tech. /SLAC},
abstractNote = {A new laser-wire (LW) system has been installed at the ATF extraction line at KEK, Tsukuba. The system aims at a micron-scale laser spot size and employs a mode-locked laser system. The purpose-built interaction chamber, light delivery optics, and lens systems are described, and the first results are presented.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Feb 12 00:00:00 EST 2007},
month = {Mon Feb 12 00:00:00 EST 2007}
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share:
  • A new laser-wire is being installed in the extraction line of the ATF at KEK. This device aims at demonstrating that laser-wires can be used to measure micrometre scale beam size.
  • Emittance measurements performed in the diagnostic section of the Accelerator Test Facility (ATF) extraction line since 1998 led to vertical emittances three times larger than the expected ones, with a strong dependence on intensity. An experimental program is pursued to investigate potential sources of emittance growth and find possible remedies. This requires efficient and reliable emittance measurement techniques. In the past, several phase-space reconstruction methods developed at SLAC and KEK have been used to estimate the vertical emittance, based on multiple location beam size measurements and dedicated quadrupole scans. These methods have been shown to be very sensitive to measurementmore » errors and other fluctuations in the beam conditions. In this context new emittance measurements have been performed revisiting these methods and newly developed ones with a systematic approach to compare and characterise their performance in the ATF extraction line.« less
  • Since several years, the vertical beam emittance measured in the Extraction Line (EXT) of the Accelerator Test Facility (ATF) at KEK, that will transport the electron beam from the ATF Damping Ring (DR) to the future ATF2 Final Focus beam line, is significantly larger than the emittance measured in the DR itself, and there are indications that it grows rapidly with increasing beam intensity. This longstanding problem has motivated studies of possible sources of this anomalous emittance growth. One possible contribution is non-linear magnetic fields in the extraction region experimented by the beam while passing off-axis through magnets of themore » DR during the extraction process. In this paper, simulations of the emittance growth are presented and compared to observations. These simulations include the effects of predicted non-linear field errors in the shared DR magnets and orbit displacements from the reference orbit in the extraction region. Results of recent measurements using closed orbit bumps to probe the relation between the extraction trajectory and the anomalous emittance growth are also presented.« less
  • The initial experimental results of the Brookhaven accelerator test facility (ATF) in-line injector is presented. The ATF in-line injector employed a full copper RF gun with a pair of solenoid magnets for emittance compensation. The maximum acceleration field of the RF gun was measured to be 130 MV/m. The electron yield from the copper cathode was maximized using p- polarized laser and the Schottky effect. The quantum efficiency under optimum conditions was measured to be 0.04%. The measured electron bunch length was less than 11 ps, which agreed with the laser pulse length measurement using a streak camera. The normalizedmore » rms. emittance for 0.25 nC charge is 0.9 {plus_minus} 0.1 mm-mrad, which is almost four times smaller than the emittance predicted by the space-charge effect for a non-emittance compensation photocathode RF gun. The normalized rms for 0.6 nC charge was measured range from 1 to 3 mm-mrad. This measurement was first experimental demonstration of emittance compensation in a high-gradient, S-band photocathode RF gun.« less
  • Recent results of the electron density profile measurement on the Advanced Toroidal Facility (ATF) are presented. A multichannel difluoromethane laser interferometer system has been routinely employed to study density evolution in ECH as well as neutral-beam-heated plasma discharges with gas fueling and pellet injection. A chordal inversion code has been developed, and has been used successfully to reconstruct the asymmetric density profiles. Cross-correlation of density profiles measurements among FIR interferometer, Thomson scattering, the heavy-ion beam probe, and the fast reciprocating Langmuir probe has been achieved. Radial density profiles measured by the four diagnostics are generally in good agreement and aremore » hollow profiles under most experimental conditions.« less