Experimental determination of the phase differences of continuum wavefunctions describing the photoionisation process of xenon atoms. I. Measurements of the spin polarisations of photoelectrons and their comparison with theoretical results

The photoionisation of xenon is completely described by the knowledge of either three or five parameters, corresponding respectively to the 2 P 1/2 and 2 P 3/2 states of the ion, and their dependence on photon energy. In the photon energy range from 12 to 41 eV two of these have been experimentally determined from measurements of the spin polarisation of photoelectrons emitted by unpolarised and circularly polarised VUV radiation. After a description of the apparatus used the measured results are presented and compared with different theoretical results.