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

Title: Photon Dose Yield Model for High-Intensity Short-Pulse Laser-Solid Experiments

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC); UK EPSRC
OSTI Identifier:
1318066
Report Number(s):
SLAC-PUB-16783
DOE Contract Number:
AC02-76SF00515
Resource Type:
Journal Article
Resource Relation:
Journal Name: Radiation Protection Dosimetry
Country of Publication:
United States
Language:
English
Subject:
OPTICS, SAFETY, OTHER

Citation Formats

Liang, T., /SLAC /Georgia Tech, Bauer, J., Liu, J., Rokni, S., and /SLAC. Photon Dose Yield Model for High-Intensity Short-Pulse Laser-Solid Experiments. United States: N. p., 2016. Web.
Liang, T., /SLAC /Georgia Tech, Bauer, J., Liu, J., Rokni, S., & /SLAC. Photon Dose Yield Model for High-Intensity Short-Pulse Laser-Solid Experiments. United States.
Liang, T., /SLAC /Georgia Tech, Bauer, J., Liu, J., Rokni, S., and /SLAC. Thu . "Photon Dose Yield Model for High-Intensity Short-Pulse Laser-Solid Experiments". United States. doi:. https://www.osti.gov/servlets/purl/1318066.
@article{osti_1318066,
title = {Photon Dose Yield Model for High-Intensity Short-Pulse Laser-Solid Experiments},
author = {Liang, T. and /SLAC /Georgia Tech and Bauer, J. and Liu, J. and Rokni, S. and /SLAC},
abstractNote = {},
doi = {},
journal = {Radiation Protection Dosimetry},
number = ,
volume = ,
place = {United States},
year = {Thu Sep 01 00:00:00 EDT 2016},
month = {Thu Sep 01 00:00:00 EDT 2016}
}
  • A bremsstrahlung source term has been developed by the Radiation Protection (RP) group at SLAC National Accelerator Laboratory for high-intensity short-pulse laser–solid experiments between 10 17 and 10 22 W cm –2. This source term couples the particle-in-cell plasma code EPOCH and the radiation transport code FLUKA to estimate the bremsstrahlung dose yield from laser–solid interactions. EPOCH characterizes the energy distribution, angular distribution, and laser-to-electron conversion efficiency of the hot electrons from laser–solid interactions, and FLUKA utilizes this hot electron source term to calculate a bremsstrahlung dose yield (mSv per J of laser energy on target). The goal of thismore » paper is to provide RP guidelines and hazard analysis for high-intensity laser facilities. In conclusion, a comparison of the calculated bremsstrahlung dose yields to radiation measurement data is also made.« less
  • A plasma channel is formed behind a self-guided, subpicosecond, 2TW laser pulse in a hydrogen gas jet plasma. The channel is produced from the radial expulsion of plasma ions due to charge separation created in the displacement (or cavitation) of plasma electrons by the large ponderomotive force of the laser. Using Thomson scattering diagnostics and mode structure measurements, an intense trailing laser pulse (I{approximately}5{times}10{sup 16}W/cm{sup 2}) is observed to be guided throughout the length of this channel for about 20 Rayleigh lengths, approximately equal to the propagation length of the self-guided pump laser pulse. {copyright} {ital 1997} {ital The Americanmore » Physical Society}« less
  • The transport of fast electrons generated by 1 ps, 1 {mu}m wavelength laser pulses focused to spot diameters of 20 {mu}m and peak intensities of up to 2{times}10{sup 18} Wcm{sup {minus}2} on to solid aluminum targets is considered using a relativistic Fokker-Planck equation, which is solved by reducing it to an equivalent system of stochastic differential equations. The background is represented by {bold E}={eta}{bold j}{sub b}, where {eta} is the resistivity and {bold j}{sub b} is the background current density. Collisions, electric and magnetic fields, and changes in resistivity due to heating of the background are included. Rotational symmetry ismore » assumed. The treatment is valid for fast electron number densities much less than that of the background, fast electron energies much greater than the background temperature, and time scales short enough that magnetic diffusion and thermal conduction are negligible. The neglect of ionization also limits the validity of the model. The intensities at which electric and magnetic fields become important are evaluated. The electric field lowers the energy of fast electrons penetrating the target. The magnetic field reduces the radial spread, increases the penetration of intermediate energy fast electrons, and reflects lower energy fast electrons. Changes in resistivity significantly affect the field generation. The implications for K{alpha} emission diagnostics are discussed. {copyright} {ital 1997} {ital The American Physical Society}« less
  • We observe the proton signals with thin-foil polyimide and copper targets with a high-intensity Ti:sapphire laser pulse. High-energy protons with the maximum energy of 2.3 MeV for 7.5 {mu}m thick polyimide target and 1.2 MeV for 3 {mu}m thick copper target are generated at the laser intensity of {approx}1x10{sup 19} W/cm{sup 2} under preformed plasma condition.