Development of backlighting sources for Compton radiography diagnostic of Inertial Confinement Fusion targets.

Published

December 8, 2008

Author(s)

Lawrence T. Hudson, A. Tommasini, A MacPhee, D. Hey, T Ma, C. Chen, N Izimi, W Unites, A. MacKinnon, P. Hatchett, B.A. Remington, H.S. Park, P. Springer, J. Koch, O.L. Landen, John F. Seely, G Holland

Abstract

We present scaled demonstrations of backlighter sources, emitting Bremsstrahlung x rays with photon energies above 75 keV, that we will use to record x-ray Compton radiographic snapshots of cold dense DT fuel in inertial confinement fusion implosions at the National Ignition Facility (NIF). In experiments performed at the Titan laser facility at Lawrence Livermore National Laboratory, we measured the source size and the Bremsstrahlung spectrum as a function of laser intensity and pulse length from solid targets irradiated at 2e17 W/cm2 to 5e18 W/cm2 using 2 ps to 40 ps pulses. Using Au planar foils we achieved source sizes down to 5.5 µm, and conversion efficiencies of about 1e-3 J/J into x-ray photons with energies in the 75 keV to 100 keV spectral range. We can now use these results to design NIF backlighter targets and shielding, and to predict Compton radiography performance as a function of the NIF implosion yield and associated background.

Citation

Review of Scientific Instruments

Volume

79

Issue

10E901

Pub Type

Journals

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Keywords

laser-plasma interaction, hard x rays, x-ray spectroscopy, radiography

Citation

Hudson, L. , Tommasini, A. , MacPhee, A. , Hey, D. , Ma, T. , Chen, C. , Izimi, N. , Unites, W. , MacKinnon, A. , Hatchett, P. , Remington, B. , Park, H. , Springer, P. , Koch, J. , Landen, O. , Seely, J. and Holland, G. (2008), Development of backlighting sources for Compton radiography diagnostic of Inertial Confinement Fusion targets., Review of Scientific Instruments, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=842500 (Accessed January 2, 2025)