Testing a Cherenkov neutron time-of-flight detector on OMEGA

V Yu Glebov; M J Eckart; C J Forrest; G P Grim; E P Hartouni; R Hatarik; J P Knauer; A S Moore; S P Regan; T C Sangster; D J Schlossberg; C Stoeckl

doi:10.1063/1.5035289

Testing a Cherenkov neutron time-of-flight detector on OMEGA

Rev Sci Instrum. 2018 Oct;89(10):10I122. doi: 10.1063/1.5035289.

Authors

Affiliations

¹ Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623-1299, USA.
² Lawrence Livermore National Laboratory, Livermore, California 94550, USA.

PMID: 30399883
DOI: 10.1063/1.5035289

Abstract

A Cherenkov neutron time-of-flight (nTOF) detector developed and constructed at Lawrence Livermore National Laboratory was tested at 13 m from the target in a collimated line of sight (LOS) and at 5.3 m from the target in the open space inside the OMEGA Target Bay. Neutrons interacting with the quartz rod generate gammas, which through Compton scattering produce relativistic electrons that give rise to Cherenkov light. A photomultiplier tube (PMT) transferred the Cherenkov light into an amplified electrical signal. The Cherenkov nTOF detector consists of an 8-mm-diam, 25-cm quartz hexagonal prism coupled with a Hamamatsu gated PMT R5916U-52. The tests were performed with DT direct-drive implosions with cryogenic and room-temperature targets, producing a wide range of neutron yields and ion temperatures. The results of the tests and comparison with other nTOF detectors on OMEGA are presented. In the collimated LOS at 13 m from the target, the Cherenkov nTOF detector demonstrated good precision measurement in both the yield and ion temperature for DT yields above 3 × 10¹³.