A novel method to recover DD fusion proton CR-39 data corrupted by fast ablator ions at OMEGA and the National Ignition Facility

Abstract

CR-39 detectors are used routinely in inertial confinement fusion (ICF) experiments as a part of nuclear diagnostics. CR-39 is filtered to stop fast ablator ions which have been accelerated from an ICF implosion due to electric fields caused by laser-plasma interactions. In some experiments, the filtering is insufficient to block these ions and the fusion-product signal tracks are lost in the large background of accelerated ion tracks. A technique for recovering signal in these scenarios has been developed, tested, and implemented successfully. The technique involves removing material from the surface of the CR-39 to a depth beyond the endpoint of the ablator ion tracks. The technique preserves signal magnitude (yield) as well as structure in radiograph images. The technique is effective when signal particle range is at least 10 μm deeper than the necessary bulk material removal.

Response of nuclear track detector CR-39 to low energy muons

“…As CR-39 is primarily used for neutron and charged particle dosimetry, there are many studies characterising the detector for given particles species and energy ranges, allowing the relationship between energy and particle track diameter to be well understood [9,13,19]. Characterisation of CR-39's response to relatively low (<10 MeV) energy muons does not appear to have been investigated.…”

“…A commercially available SSNTD is a plastic more commonly known by its trademarked name, CR-39 (Columbia Resin #39), chemical name PADC (PolyAllyl Diglycol Carbonate). It is used in a wide range of science and technology applications, from eyeglass lenses to inertial confinement fusion experiments [9]. Its response to protons [10], neutrons [11], alpha particles [12], and heavier ions [13] is well studied, and there are examples of its use to study the spectral properties of laser accelerated proton beams in particular [16].…”