Experimental investigation on nuclear reactions using a laser-accelerated proton and deuteron beam

Abstract

We report an experimental investigation on nuclear reactions using an intense, ultra-short laser-accelerated proton and deuteron beam generated by the interaction of 25 fs, 150 TW Ti: sapphire laser pulse with normal thin foils and foils containing deuterium atoms. The production of a positron-emitting short-lived 11C radio-isotope from the interaction of protons and deuterium ions with a solid boron palette by means of 11B (p, n)11C and 10B (d, n)11C nuclear reactions was studied. The maximum radioactivity in the optimized laser irradiation condition was found to be 5.2 kBq per laser shot, which corresponds to ∼9 × 106 atoms of 11C isotopes using the 11B (p, n)11C reaction. The relative efficiency of 11C production using a proton and deuteron beam was also explored experimentally. About 30 % enhancement in 11C activity was observed with CD2 coated targets. It was also found that because of the relatively low deuteron energy threshold of the reaction 10B (d, n)11C, even the low energy part of the accelerated deuterons in the spectrum can be used for efficient 11C production. In the same setup, the proton-induced fusion reaction in the boron target (p + 5B11 ⇒ 3α + 8.7 MeV) was also studied. The resultant fusion yield and alpha particle energy spectrum was measured.