Laser induced fluorescence study of Xe(5<i>p</i>56<i>p</i>, 5<i>p</i>56<i>p</i>′, 5<i>p</i>57<i>p</i>, and 5<i>p</i>56<i>d</i>) states in Ne and Ar: Radiative lifetimes and collisional deactivation rate constants

Abstract

The radiative lifetimes and the collisional deactivation constants by Ne and Ar for all 6p, 6p′, 7p, and 6d states of Xe, except two, were studied by single or two-photon laser induced fluorescence in the afterglow of a pulsed discharge [the prime symbol denotes the Xe+(2P1/2) core rather than the Xe+(2P3/2) core]. The radiative lifetimes, 30–48 ns for 6p and 6p′ states and 68–172 ns for 7p states, agree well with theoretical values; but, the agreement between experiment and theory is less satisfactory for the 6d states. The collisional deactivation constants for Ne and Ar are similar if there is a nearby product level. However, the deactivation constants by Ar are much larger than for Ne, if there is a large energy defect for the product state. The product distributions also were measured; Ar collisions give products with larger energy defect than collisions with Ne, which tend to favor nearly isoenergetic product states. The number and type of product channels are related to the locations of crossings in the Rg–Xe potential curves and the more attractive nature of Ar–Xe* vs Ne–Xe*. There is no clear favoring between intra- and intermultiplet product states of Xe*. The radiative cascading (6p′,7p)→(7s or 4d)→6p also was studied.