Abstract
Absolute elastic differential cross sections of atomic hydrogen have been measured by a modulated crossed-beam method. The energy and angular range covered were from 5 to 30 eV and from 12° to 156°, respectively. The present results agree with the previous measurements within the experimental uncertainty below 15 eV, but it is found that the present results show stronger backward scattering (>120°) than the previous measurement and theoretical results by more than a factor of 2 above 20 eV.