Hohlraum glint and laser pre-pulse detector for NIF experiments using velocity interferometer system for any reflector

J D Moody; T J Clancy; G Frieders; P M Celliers; J Ralph; D P Turnbull

doi:10.1063/1.4887155

Hohlraum glint and laser pre-pulse detector for NIF experiments using velocity interferometer system for any reflector

Rev Sci Instrum. 2014 Nov;85(11):11E608. doi: 10.1063/1.4887155.

Authors

J D Moody¹, T J Clancy¹, G Frieders¹, P M Celliers¹, J Ralph¹, D P Turnbull¹

Affiliation

¹ Lawrence Livermore National Laboratory, Livermore, California 94550, USA.

PMID: 25430354
DOI: 10.1063/1.4887155

Abstract

Laser pre-pulse and early-time laser reflection from the hohlraum wall onto the capsule (termed "glint") can cause capsule imprint and unwanted early-time shocks on indirect drive implosion experiments. In a minor modification to the existing velocity interferometer system for any reflector diagnostic on NIF a fast-response vacuum photodiode was added to detect this light. The measurements show evidence of laser pre-pulse and possible light reflection off the hohlraum wall and onto the capsule.