Impact of x-ray dose on the response of CR-39 to 1-5.5 MeV alphas

• Main Authors: Rojas Herrera, Jimmy A. (Contributor), Rinderknecht, Hans George (Contributor), Zylstra, Alex Bennett (Contributor), Gatu Johnson, Maria (Contributor), Orozco, David (Contributor), Rosenberg, Michael Jonathan (Contributor), Sio, Hong Weng (Contributor), Seguin, Fredrick Hampton (Contributor), Frenje, Johan A (Contributor), Li, C. K. (Contributor), Petrasso, Richard D (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Physics (Contributor), Massachusetts Institute of Technology. Plasma Science and Fusion Center (Contributor)
• Format: Article
• Language: English
• Published: American Institute of Physics (AIP), 2017-09-13T15:42:47Z.
• Subjects: Article
• Online Access: Get fulltext

The CR-39 nuclear track detector is used in many nuclear diagnostics fielded at inertial confinement fusion (ICF) facilities. Large x-ray fluences generated by ICF experiments may impact the CR-39 response to incident charged particles. To determine the impact of x-ray exposure on the CR-39 response to alpha particles, a thick-target bremsstrahlung x-ray generator was used to expose CR-39 to various doses of 8 keV Cu-K[subscript α] and K[subscript β] x-rays. The CR-39 detectors were then exposed to 1-5.5 MeV alphas from an Am-241 source. The regions of the CR-39 exposed to x-rays showed a smaller track diameter than those not exposed to x-rays: for example, a dose of 3.0 ± 0.1 Gy causes a decrease of (19 ± 2)% in the track diameter of a 5.5 MeV alpha particle, while a dose of 60.0 ± 1.3 Gy results in a decrease of (45 ± 5)% in the track diameter. The reduced track diameters were found to be predominantly caused by a comparable reduction in the bulk etch rate of the CR-39 with x-ray dose. A residual effect depending on alpha particle energy is characterized using an empirical formula.
United States. Department of Energy (Grant DE-NA0001857)