Deexcitation of He(2 1P) in a collision with Ne

Collisional deexcitation cross sections of He(2 1P) by Ne have been measured in a region of the mean collisional energy between 17 and 38 meV using a pulse-radiolysis method. Measured cross sections are in a range of 20–25 Å2 and increase with increasing collisional energy. The experimental cross sections are compared with the calculated ones for total and partial excitation transfer into highly excited Ne atoms. Fairly good agreement between calculated and experimental results indicates that in the deexcitation of He(2 1P) the excitation transfer into Ne*(6p3, 5s2, or 6s4) is important in the measured mean collisional energy region. It is also shown that a dipole–dipole interaction plays an important role in the excitation transfer from He(2 1P) to Ne.