Measurements of the optical contrast on OMEGA: a 60-beam, 30-kJ UV fusion laser

Author

Boehly, T.R. ; Meyerhofer, D.D. ; Fisher, Y. ; Seka, W. ; Bradley, D.K.

Author_Institution

Lab. for Laser Energetics, Rochester Univ., NY, USA

fYear

2000

fDate

7-12 May 2000

Firstpage

539

Abstract

Summary form only given. For most direct-drive ICF experiments, it is important that the 0.5- to 4-ns laser pulses that irradiate targets on OMEGA have high optical contrast. Using a photodiode that is sensitive to intensities that are 10/sup -8/ of the main OMEGA pulse, the UV output of OMEGA was measured for a duration of /spl sim/20 ns before the arrival of the main pulse. By cross-calibrating this with the main pulse shape, we constructed the entire temporal pulse shape over 20 ns and over approximately eight orders of magnitude. To assess the tolerable level of contrast, we performed experiments that probe the Al barrier layers placed on most OMEGA targets. We also correlate the performance of imploding spherical targets with the measured optical contrast.

Keywords

high-speed optical techniques; laser fusion; laser variables measurement; light interferometry; optical correlation; photodiodes; 20 ns; 30 kJ; Al; Al barrier layers; OMEGA; UV fusion laser; UV output; cross-calibrating; direct-drive ICF experiments; high optical contrast; imploding spherical targets; main pulse shape; measured optical contrast; ns laser pulses; optical contrast; photodiode; temporal pulse shape; Laser fusion;

fLanguage

English

Publisher

ieee

Conference_Titel

Lasers and Electro-Optics, 2000. (CLEO 2000). Conference on

Conference_Location

San Francisco, CA, USA

Print_ISBN

1-55752-634-6

Type

conf

DOI

10.1109/CLEO.2000.907360

Filename

907360