Ionization of hydrogen atoms by electron impact at 1, 0.5, and0.3eVabove threshold

Abstract

We present here triple differential cross sections for ionization of hydrogen atoms by electron impact at 1, 0.5, and $0.3\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ energy above threshold, calculated in the hyperspherical partial wave theory. The results are in very good agreement with the available semiclassical results of Deb and Crothers [Phys. Rev. A 65, 052721 (2002)] for these energies. With this, we are able to demonstrate that the hyperspherical partial-wave theory yields good cross sections from $30\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ [Phys. Rev. A 67, 042717 (2003)] down to near threshold for equal-energy-sharing kinematics.