Channeling of MeV Projectiles in Tungsten and Silicon

Wide-angle Rutherford scattering has been used to investigate experimentally the channeling behavior of several projectiles (${}_{}{}^1{}_{}{}^{}\mathrm{H}$, ${}_{}{}^4{}_{}{}^{}\mathrm{He}$, ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, and ${}_{}{}^{35}{}_{}{}^{}\mathrm{Cl}$) in tungsten crystals in the energy region 2 to 30 MeV; the study has also been extended to silicon crystals, using a 3.0-MeV ${}_{}{}^1{}_{}{}^{}\mathrm{H}$ beam. The observed critical angles and minimum scattering yields are compared with theoretical predictions. In general, the agreement is excellent. In both W and Si, precise energy analysis of the scattered beam has also provided detailed information on the depth and temperature dependence of channeling; a marked difference is observed between the planar and axial channeling processes. Some preliminary measurements in Au and U${\mathrm{O}}_2$ crystals are included.