Detection of limited-energy α particles using CR-39 in laser-induced p −11B reaction

Abstract

Due to the harsh radiation environment produced by strong laser plasma, most of the detectors based on semiconductors cannot perform well. So, it is important to develop new detecting techniques with higher detection thresholds and highly charged particle resolution for investigating nuclear fusion reactions in laser-plasma environments. The Columbia Resin No. 39 (CR-39) detector is mainly sensitive to ions and insensitive to the backgrounds, such as electrons and photons. The detector has been widely used to detect charged particles in laser-plasma environments. In this work, we used a potassium–ethanol–water (PEW) etching solution to reduce the proton sensitivity of CR-39, by raising the detection threshold for the research of laser-induced 11B(p, α)2α reaction. We calibrated the 3–5 MeV α particles in an etching condition of 60°C PEW-25 solution (17% KOH + 25%C2H5OH + 58%H2O) and compared them with the manufacturer’s recommended etching conditions of 6.25 N NaOH aqueous solution at 98°C in our laser-induced nuclear reaction experiment. The results indicate, with the PEW-25 solution, that CR-39 is more suitable to distinguish α tracks from the proton background in our experiment. We also present a method to estimate the minimum detection range of α energy on specific etching conditions in our experiment.

CR-39 track detector calibration with H and He beams for applications in the p-11B fusion reaction

“…This causes bulk etching of plastic, and because of the enhanced etching properties of the regions exposed to radiation, tracks become visible and with sizes increasing with the duration of the bath. The etched tracks can be visualised and analysed under an optical microscope, providing valuable information about the properties of the particles involved [12,13] Advantages of CR39 detectors in studying p-11B fusion reactions include:…”

Perspectives on research on laser driven proton-boron fusion and applications

“…For example, α-particles will have the same position as 12 C 6+ ions with three times bigger energy. In such cases, a discrimination might be performed by using SSNTD detectors, since traces may have fairly different diameters [60] and again putting filters in front of the SSNTD.…”

“…Due to the limitation of state-of-the-art diagnostic approaches, it is necessary to develop innovative new diagnostic methods [19,[58][59][60][61], or modify and upgrade the existing solutions. For instance, it will be possible to get information on pB reactions from studying other reactions occurring in the same experiment, and secondary generating products that can be detected more easily.…”