Impact of x-ray dose on track formation and data analysis for CR-39-based proton diagnostics

Journal Article · Tue Dec 15 00:00:00 EST 2015 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.4938161· OSTI ID:22482646

Rojas-Herrera, J.; Zylstra, A. B.; Frenje, J. A.; Gatu Johnson, M.; Sio, H.; Sinenian, N.; Rosenberg, M. J.; Li, C. K.; Séguin, F. H.; Petrasso, R. D. ^[1]; Filkins, T.; Steidle, Jessica A.; Traynor, N.; Freeman, C. ^[2]; Steidle, Jeffrey A. ^[3]

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1. Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)
2. State University of New York at Geneseo, Geneseo, New York 14454 (United States)
3. Rochester Institute of Technology, Rochester, New York 14623 (United States)

The nuclear track detector CR-39 is used extensively for charged particle diagnosis, in particular proton spectroscopy, at inertial confinement fusion facilities. These detectors can absorb x-ray doses from the experiments in the order of 1–100 Gy, the effects of which are not accounted for in the previous detector calibrations. X-ray dose absorbed in the CR-39 has previously been shown to affect the track size of alpha particles in the detector, primarily due to a measured reduction in the material bulk etch rate [Rojas-Herrera et al., Rev. Sci. Instrum. 86, 033501 (2015)]. Similar to the previous findings for alpha particles, protons with energies in the range 0.5–9.1 MeV are shown to produce tracks that are systematically smaller as a function of the absorbed x-ray dose in the CR-39. The reduction of track size due to x-ray dose is found to diminish with time between exposure and etching if the CR-39 is stored at ambient temperature, and complete recovery is observed after two weeks. The impact of this effect on the analysis of data from existing CR-39-based proton diagnostics on OMEGA and the National Ignition Facility is evaluated and best practices are proposed for cases in which the effect of x rays is significant.

• OSTI ID: 22482646
• Journal Information: Review of Scientific Instruments, Vol. 86, Issue 12; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
ALPHA PARTICLES
AMBIENT TEMPERATURE
CALIBRATION
DATA ANALYSIS
ETCHING
INERTIAL CONFINEMENT
MEV RANGE 01-10
PROTONS
SPECTROSCOPY
US NATIONAL IGNITION FACILITY
X RADIATION