Changes in CR-39 proton sensitivity due to prolonged exposure to high vacuums relevant to the National Ignition Facility and OMEGA

M J-E Manuel; M J Rosenberg; N Sinenian; H Rinderknecht; A B Zylstra; F H Séguin; J Frenje; C K Li; R D Petrasso

doi:10.1063/1.3635537

Changes in CR-39 proton sensitivity due to prolonged exposure to high vacuums relevant to the National Ignition Facility and OMEGA

Rev Sci Instrum. 2011 Sep;82(9):095110. doi: 10.1063/1.3635537.

Authors

M J-E Manuel¹, M J Rosenberg, N Sinenian, H Rinderknecht, A B Zylstra, F H Séguin, J Frenje, C K Li, R D Petrasso

Affiliation

¹ Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.

PMID: 21974622
DOI: 10.1063/1.3635537

Abstract

When used at facilities like OMEGA and the NIF, CR-39 is exposed to high vacuum environments before and after irradiation by charged particles and neutrons. Using an electrostatic linear accelerator at MIT, studies have been conducted to investigate the effects of high vacuum exposure on the sensitivity of CR-39 to fusion protons in the ~1-9 MeV energy range. High vacuum conditions, of order 10(-5) Torr, experienced by CR-39 samples at these facilities were emulated. It is shown that vacuum exposure times longer than ~16 h before proton irradiation result in a decrease in proton sensitivity, whereas no effect was observed for up to 67 h of vacuum exposure after proton irradiation. CR-39 sensitivity curves are presented for samples with prolonged exposure to high vacuum before and after proton irradiation.