HARD SHAPE POTENTIALS FROM ROTATIONAL STATE-TO-STATE INELASTIC CROSS-SECTIONS - A POSSIBLE ROUTE TO INVERSION

A two-parameter hard shape potential has been deduced which reproduces previously reported rotationally inelastic integral cross sections for He-HF collisions. A potential optimized to the 0-->1 and 0-->2 cross sections at a collision energy of 41.4 meV reproduces well other DELTA-j = +/- 1 and +/- 2 cross sections at this energy and at 81.9 meV. The potential is quite close to the 81.9 meV contour surface of a published He-HF potential. If this surface is used to define the hard shape potential then, although the DELTA-j = +/- 2 and DELTA-j = +/- 3 cross sections are improved, the DELTA-j = +/- 1 cross sections are approximately 50% too large.