Low-energy triple differential cross sections of atomic hydrogen: angular correlation measurements at 54.4 eV incident energy

Triple differential cross sections of the electron impact ionisation of atomic hydrogen have been measured at 54.4 eV primary energy and 5 eV detection energy of the slow secondary electrons. The relative shape of the cross section and its variation as a function of the scattering angle of the fast outgoing electron is different from the behaviour found at intermediate and high energies. The experimental results are compared with the recent pseudostate close-coupling theory of Curran and Walters.