Detection of alpha particles from 7Li(p,α)4He and 19F(p,α)16O reactions induced by laser-accelerated protons using CR-39 with potassium hydroxide-ethanol-water etching solution

Yosuke Nishiura; Shunsuke Inoue; Sadaoki Kojima; Kensuke Teramoto; Yuki Furukawa; Masaki Hashida; Shuji Sakabe

doi:10.1063/1.5098863

Detection of alpha particles from ⁷Li(p,α)⁴He and ¹⁹F(p,α)¹⁶O reactions induced by laser-accelerated protons using CR-39 with potassium hydroxide-ethanol-water etching solution

Rev Sci Instrum. 2019 Aug;90(8):083307. doi: 10.1063/1.5098863.

Authors

Yosuke Nishiura¹, Shunsuke Inoue¹, Sadaoki Kojima¹, Kensuke Teramoto¹, Yuki Furukawa¹, Masaki Hashida¹, Shuji Sakabe¹

Affiliation

¹ Advanced Research Center for Beam Science, Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan.

PMID: 31472620
DOI: 10.1063/1.5098863

Abstract

Alpha particles generated by ⁷Li(p,α)⁴He and ¹⁹F(p,α)¹⁶O reactions are selectively detected in the presence of abundant primary protons by reducing the proton sensitivity of CR-39 using a potassium hydroxide-ethanol-water (PEW) etching solution. These nuclear reactions are induced in a LiF crystal using the laser-accelerated protons (4 × 10¹¹ protons/pulse with a maximum energy of 3.3 MeV) generated and accelerated by the interaction of a 40-fs laser pulse with a polyethylene thin film target at a peak intensity of 5 × 10¹⁹ W/cm². Subsequent etching of the CR-39 in the PEW solution (KOH: 17 wt. %; C₂H₅OH: 25 wt. %; H₂O: 58 wt. %) permits the selective detection of 4.0 MeV alpha particles, which is independently confirmed by an experiment using alpha particles from an ²⁴¹Am source. The described method is expected to be useful for research into nuclear reactions in laser plasma.