Cross section for the photochemical formation of the NaZn (22Π) excimer

Abstract

Abstract.We studied the conditions for the photochemical formation of the NaZn excimer in the excited 22//state using Naz(21//u) + Zn ~ NaZn(22//) + Na reaction. The N a -Z n vapor mixture was prepared in the heat-pipe oven with the well defined column density and temperature. The Na and Zn atom densities in the vapor mixture were controlled by the preparation of the alloy with different mole fraction ratios of the relevant components in the solid phase. The Na densities were determined from the total absorption coefficient at Nag X-B and X-A bands. The cross section for photochemical formation of the NaZn in the 22//state is estimated to be 17.10-16 c m 2 for the laser excitation at 308 rim, measured relative to the cross section of 470.10-16cm 2 for collisional energy transfer Naz(21//u) + Na ~Nai(23//g) + Na published by Mehdizadeh et al. [21.

Resonance 2s-2p excitation of lithium in the Li + Cd system

“…The slow peak comes from Li + ion recombination, which gives a cubic dependence on laser intensity. The population of lithium n > 3 atomic levels is a result of recombination of Li + ions after the ionization of lithium described in relation (8). We estimated the rate coefficient for the process described by relation (8) to be k (8) = (17 ± 15)10 −10 cm 3 s −1 .…”

“…The population of lithium n > 3 atomic levels is a result of recombination of Li + ions after the ionization of lithium described in relation (8). We estimated the rate coefficient for the process described by relation (8) to be k (8) = (17 ± 15)10 −10 cm 3 s −1 . Simulation of temporal evolution for the Li(4d) state in figure 3(e) depends only on the recombination of lithium ions and cascade emission from higher excited states.…”

“…The experimental set-up is similar to one described in [8] and here we present only a short description. Laser radiation from an excimer laser (XeCl at 308 nm, Model LPX 100E) pumped dye laser (Model FL 3000, Lambda Physik) with Rhodamin 101 dye, tuned to 670.8 nm for the Li(2p) excitation was transmitted through the heat-pipe oven containing lithium and cadmium vapours at temperatures between 813 and 1103 K. The laser beam repetition rate was 9 Hz, the usual energy of the single pulse was 0.3 mJ, which gives an intensity of 10 5 W cm −2 .…”

“…Li(2p) + Cd(5 3 P J ) → Li + + e − + Cd(5 1 S 0 ) (8) followed by radiative recombination of lithium ions and electrons into Li Rydberg states. The cross sections for relation ( 7) is about σ ion = 1.5 × 10 −17 cm 2 [18].…”

“…The Li-Cd system has been studied extensively over the last few years. Blue-green diffuse bands of the LiCd molecule have been observed as a result of photochemical reactions [7][8][9]. Several other excitation paths have also been studied [10,11].…”