Depopulation of the 53P1 state of cadmium by collisions with ground-state Cd and noble-gas atoms

Theoretical study of Na(4p2P) + Na(3s2S) and Cd(5p3P0) + Na(3s2S) collisions and their role in the energy transfer between Cd.* and Na

“…is 167Å 2 at 528 K. Collisions with rare gases [21] or with sodium atoms [16] are of negligible importance in this respect. The branching ratio between Cd(5p 3 P 0 ) and Cd(5p 3 P 2 ) for process (3) has not been determined directly, but one can assume that the 5p 3 P 0 channel dominates, by virtue of its smaller energy defect (∆E = −542 cm −1 ); in fact, the cross section is substantially independent of temperature [21,22], which would not be the case for the 5p 3 P 2 endothermic channel (∆E = 1171 cm −1 ).…”

“…The branching ratio between Cd(5p 3 P 0 ) and Cd(5p 3 P 2 ) for process (3) has not been determined directly, but one can assume that the 5p 3 P 0 channel dominates, by virtue of its smaller energy defect (∆E = −542 cm −1 ); in fact, the cross section is substantially independent of temperature [21,22], which would not be the case for the 5p 3 P 2 endothermic channel (∆E = 1171 cm −1 ). At equilibrium, with a typical heat pipe temperature of 730 K, the 5p 3 P 0 , 5p 3 P 1 and 5p 3 P 2 population ratios would be 1 : 1.03 : 0.17.…”

“…Collisions with ground state Cd, which is the most abundant species in the heat-pipe oven experiments [1], are very efficient in promoting such spin-changing transitions. The measured cross section [21] for the depopulation of 5p 3 P 1 via the process Cd(5p 3 P 1 ) + Cd(5s 1 S) → Cd(5p 3 P 0,2 ) + Cd(5s 1 S) + ∆E…”

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

“…Since kT is about 700 cm −1 for T = 1000 K the processes with energy defect larger than 700 cm −1 are not taken into account, which means that process (2) mostly will populate the Cd(5 3 P 0 ) level. The Cd(5 3 P 0 ) atoms may collide with other Cd atoms, which will induce a strong intramultiplet mixing between the Cd(5 3 P J ) states [14]: Once the Cd(5 3 P J ) population reaches a sufficiently large value, the energy-pooling collision between two excited Cd atoms becomes important [15]:…”

“…In this paper we study an intermetallic Li + Cd vapour mixture in which the Li 2p level is excited by absorption around 670.8 nm. An efficient radiative collision populating the Cd(5 3 P 0 ) level occurs, followed by intramultiplet mixing collisions [14] and the energypooling collision [15], causing the appearance of the Cd(5d 1 D 2 ), Cd(6s 3 S 1 ) and Cd(5d 3 D J ) highly excited atoms.…”