Abstract
The lambda and chi parameters for He(31P) excitation by electron impact at 81.2 eV have been measured for scattering angles in the range from 60 to 120 degrees . The values of lambda show two deep minima and the values for chi show a broad maximum value, similar to previous 21P measurements. The results are not in agreement with values calculated from the first Born approximation, a distorted-wave polarised-orbital method, a multichannel eikonal method and a first-order, many-body approximation.