DEEXCITATION OF H(2P) IN A COLLISION WITH A H-2 MOLECULE

The velocity assigned experiment of the collisional de-excitation of a H(2p) atom by a H-2 molecule is demonstrated by measuring the time-de pendent intensity of Lyman-alpha radiation emitted in the photodissoci ation of H-2 using a pulsed synchrotron radiation in the vacuum ultrav iolet region. Observed decay rates of Lyman-alpha radiation have given the rate constant or cross section for the de-excitation of H(2p) by H-2. The cross section is about 3 X 10(-14) cm2 in the region of the c ollisional velocity between 4.6 X 10(5) and 12 X 10(5) cm/s, which is several times larger than that for the H(2s) de-excitation. It has bee n concluded that the l-changing collision is quite important in the de -excitation of H(2p) by H-2.