Alignment of H(2p) in H+H to H+H(2p) collisions

The integral alignment A20 of H(2p) was measured for 3-25 keV H-H collisions. The measured A20 is at low incident energies close to zero; indicating roughly equal population of H(2p0) and H(2p+or-1) magnetic substates. This behaviour is in disagreement with recent calculations by Shingal et al. (1987-9).