Fragments from uranium irradiated by 2.1 GeV/nucleon deuterons and alpha particles

Abstract

Energy spectra at 90\ifmmode^\circ\else\textdegree\fi{} in the laboratory were obtained for He, Li, Be, and B fragments from a uranium target irradiated with 4.9 GeV protons and 2.1 GeV/nucleon deuterons and $\ensuremath{\alpha}$ particles. Data at 25 and 155\ifmmode^\circ\else\textdegree\fi{} were also obtained with the proton and $\ensuremath{\alpha}$ particle beams. In comparing the incident deuteron data with the incident proton data, it was found that the cross sections were a factor of 1.5 higher but the shapes of the energy spectra were unchanged. However, with incident $\ensuremath{\alpha}$ particles it was found that the cross sections were a factor of 3 to 4 larger, and the energy spectra were somewhat broadened indicating that the effective Coulomb barriers are 15% lower, and the apparent temperatures 1.5 MeV higher. It is concluded that in the $\ensuremath{\alpha}$ particle irradiations the deposition energies are larger than with either incident protons or incident deuterons.NUCLEAR REACTIONS $\mathrm{U}(p, x)$, $E=4.9$ GeV; $\mathrm{U}(\ensuremath{\alpha}, x)$, $E=2.1$ GeV/nucleon; $^{4}\mathrm{He}$, $^{6}\mathrm{He}$, $^{6}\mathrm{Li}$, $^{7}\mathrm{Li}$, $^{7}\mathrm{Be}$, $^{9}\mathrm{Be}$, $^{10}\mathrm{Be}$ measured ${E}_{x}$ at 90\ifmmode^\circ\else\textdegree\fi{}, $\ensuremath{\sigma}(\ensuremath{\theta})$, $\ensuremath{\sigma}$; $^{8}\mathrm{Li}$, $^{9}\mathrm{Li}$, $^{11}\mathrm{Be}$, $^{12}\mathrm{Be}$ estimated $\ensuremath{\sigma}$. $\mathrm{U}(d, x)$, $E=2.1$ GeV/nucleon; $^{4}\mathrm{He}$, $^{7}\mathrm{Li}$, $^{7}\mathrm{Be}$, $^{9}\mathrm{Be}$, $^{10}\mathrm{Be}$ measured ${E}_{x}$ at 90\ifmmode^\circ\else\textdegree\fi{}, estimated $\ensuremath{\sigma}$; $^{6}\mathrm{He}$, $^{6}\mathrm{Li}$, $^{8}\mathrm{Li}$, $^{9}\mathrm{Li}$ estimated $\ensuremath{\sigma}$.