Cross section measurement for the B10(n,t2α) three-body reaction at 4.0, 4.5, and 5.0 MeV. II. Experimental setup and results

Abstract

Cross sections of the $^{10}\mathrm{B}(n,t2\ensuremath{\alpha})$ three-body reaction were measured at ${E}_{n}=4.0$, 4.5, and 5.0 MeV using a twin gridded ionization chamber and a thin-film $^{10}\mathrm{B}$ sample. The present paper is the second part of the work. A digital data-acquisition system was developed for the gridded ionization chamber based on the waveform digitizer. A thin-film $^{10}\mathrm{B}$ sample was designed and prepared. The number of $^{10}\mathrm{B}$ atoms in the sample was determined by the relative method using the thermal neutron induced $^{10}\mathrm{B}({n}_{th},\ensuremath{\alpha})^{7}\mathrm{Li}$ and $^{6}\mathrm{Li}({n}_{th},t)^{4}\mathrm{He}$ reactions with a $^{6}\mathrm{LiF}$ sample as the reference. The measurement of the $^{10}\mathrm{B}(n,t2\ensuremath{\alpha})$ reaction was performed at the 4.5 MV Van de Graaff accelerator of Peking University. In the measurement, the double-coincidence technique was used, which involves the forward-backward and the grid-anode coincidence. In the data processing, the effective event area in the forward two-dimensional spectrum and the time window in the drift-time spectrum were employed to reject the background events. Cross sections of the $^{10}\mathrm{B}(n,t2\ensuremath{\alpha})$ and $^{10}\mathrm{B}(n,\ensuremath{\alpha})^{7}\mathrm{Li}$ reactions were obtained. The present results are compared with the data of existing measurements and evaluations.