Abstract
Absolute differential cross sections of electrons vibrationally elastically scattered from water vapor have been measured at room temperature by electron impact. A modulated crossed-beam method was used. The energy and angular range covered were from 2.2 to 20 eV and from 15° to 150°, respectively. Strong backward scattering has been observed as predicted by theory. The measured integrated and momentum-transfer cross sections are generally larger than others in the literature by 50%.