Sensitivity of chemical vapor deposition diamonds to DD and DT neutrons at OMEGA and the National Ignition Facility

N V Kabadi; H Sio; V Glebov; M Gatu Johnson; A MacPhee; J A Frenje; C K Li; F Seguin; R Petrasso; C Forrest; J Knauer; H G Rinderknecht

doi:10.1063/1.4960071

Sensitivity of chemical vapor deposition diamonds to DD and DT neutrons at OMEGA and the National Ignition Facility

Rev Sci Instrum. 2016 Nov;87(11):11D817. doi: 10.1063/1.4960071.

Authors

N V Kabadi¹, H Sio¹, V Glebov², M Gatu Johnson¹, A MacPhee³, J A Frenje¹, C K Li¹, F Seguin¹, R Petrasso¹, C Forrest², J Knauer², H G Rinderknecht³

Affiliations

¹ Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
² Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA.
³ Lawrence Livermore National Laboratory, Livermore, California 94550, USA.

PMID: 27910431
DOI: 10.1063/1.4960071

Abstract

The particle-time-of-flight (pTOF) detector at the National Ignition Facility (NIF) is used routinely to measure nuclear bang-times in inertial confinement fusion implosions. The active detector medium in pTOF is a chemical vapor deposition diamond. Calibration of the detectors sensitivity to neutrons and protons would allow measurement of nuclear bang times and hot spot areal density (ρR) on a single diagnostic. This study utilizes data collected at both NIF and Omega in an attempt to determine pTOF's absolute sensitivity to neutrons. At Omega pTOF's sensitivity to DT-n is found to be stable to within 8% at different bias voltages. At the NIF pTOF's sensitivity to DD-n varies by up to 59%. This variability must be decreased substantially for pTOF to function as a neutron yield detector at the NIF. Some possible causes of this variability are ruled out.