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Title: Aluminum-coated optical fibers as efficient infrared timing fiducial photocathodes for synchronizing x-ray streak cameras

Abstract

The timing fiducial system at the Nova Two-Beam Facility allows time-resolved x-ray and optical streak camera data from laser-produced plasmas to be synchronized to within 30 ps. In this system, an Al-coated optical fiber is inserted into an aperture in the cathode plate of each streak camera. The coating acts as a photocathode for a low-energy pulse of 1{omega} ({lambda} = 1.054 {mu}m) light which is synchronized to the main Nova beam. The use of the fundamental (1{omega}) for this fiducial pulse has been found to offer significant advantages over the use of the 2{omega} second harmonic ({lambda} = 0.53 {mu}m). These advantages include brighter signals, greater reliability, and a higher relative damage threshold, allowing routine use without fiber replacement. The operation of the system is described, and experimental data and interpretations are discussed which suggest that the electron production in the Al film is due to thermionic emission. The results of detailed numerical simulations of the relevant thermal processes, undertaken to model the response of the coated fiber to 1{omega} laser pulses, are also presented, which give qualitative agreement with experimental data. Quantitative discrepancies between the modeling results and the experimental data are discussed, and suggestions for further researchmore » are given.« less

Authors:
;  [1]
  1. Lawrence Livermore National Laboratory, University of California, P. O. Box 5508, Livermore, California 94550 (US)
Publication Date:
OSTI Identifier:
5727584
DOE Contract Number:  
W-7405-ENG-48
Resource Type:
Journal Article
Journal Name:
Journal of Applied Physics; (USA)
Additional Journal Information:
Journal Volume: 69:10; Journal ID: ISSN 0021-8979
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; NOVA FACILITY; PLASMA DIAGNOSTICS; OPTICAL FIBERS; SURFACE COATING; STREAK CAMERAS; TIMING PROPERTIES; ALUMINIUM; DAMAGE; OPERATION; PHOTOCATHODES; CAMERAS; CATHODES; DEPOSITION; ELECTRODES; ELEMENTS; FIBERS; MEASURING INSTRUMENTS; METALS; RADIATION DETECTORS; 700102* - Fusion Energy- Plasma Research- Diagnostics; 700208 - Fusion Power Plant Technology- Inertial Confinement Technology

Citation Formats

Koch, J A, and MacGowan, B J. Aluminum-coated optical fibers as efficient infrared timing fiducial photocathodes for synchronizing x-ray streak cameras. United States: N. p., 1991. Web. doi:10.1063/1.347631.
Koch, J A, & MacGowan, B J. Aluminum-coated optical fibers as efficient infrared timing fiducial photocathodes for synchronizing x-ray streak cameras. United States. doi:10.1063/1.347631.
Koch, J A, and MacGowan, B J. Wed . "Aluminum-coated optical fibers as efficient infrared timing fiducial photocathodes for synchronizing x-ray streak cameras". United States. doi:10.1063/1.347631.
@article{osti_5727584,
title = {Aluminum-coated optical fibers as efficient infrared timing fiducial photocathodes for synchronizing x-ray streak cameras},
author = {Koch, J A and MacGowan, B J},
abstractNote = {The timing fiducial system at the Nova Two-Beam Facility allows time-resolved x-ray and optical streak camera data from laser-produced plasmas to be synchronized to within 30 ps. In this system, an Al-coated optical fiber is inserted into an aperture in the cathode plate of each streak camera. The coating acts as a photocathode for a low-energy pulse of 1{omega} ({lambda} = 1.054 {mu}m) light which is synchronized to the main Nova beam. The use of the fundamental (1{omega}) for this fiducial pulse has been found to offer significant advantages over the use of the 2{omega} second harmonic ({lambda} = 0.53 {mu}m). These advantages include brighter signals, greater reliability, and a higher relative damage threshold, allowing routine use without fiber replacement. The operation of the system is described, and experimental data and interpretations are discussed which suggest that the electron production in the Al film is due to thermionic emission. The results of detailed numerical simulations of the relevant thermal processes, undertaken to model the response of the coated fiber to 1{omega} laser pulses, are also presented, which give qualitative agreement with experimental data. Quantitative discrepancies between the modeling results and the experimental data are discussed, and suggestions for further research are given.},
doi = {10.1063/1.347631},
journal = {Journal of Applied Physics; (USA)},
issn = {0021-8979},
number = ,
volume = 69:10,
place = {United States},
year = {1991},
month = {5}
}