Deexcitation time shortening for the electronic states of trapped oxygen by matrix doping. I. Theoretical aspects

Abstract

The shortening of the 1S level lifetime of a rare gas trapped oxygen atom is interpreted according to the following scheme: a perturber disturbs the Oh ideal environment around the oxygen atom and induces a transition dipole moment for the 1S → 1D normally quadrupolar transition. We choose to represent the perturber by a foreign rare gas atom also trapped in the matrix since (i) the rare gas–rare gas interaction potential is generally of good quality and (ii) double doping experiments are easily performed. The distortion induced by the perturber is calculated at any lattice point of the crystal in the framework of the Green static functions. The energies of the level correlating with 1S and of the five levels correlating with 1D are determined together with the transition dipole elements. The bar spectrum is then reconstructed and the lifetime of the 1S level calculated, as a function of the oxygen-perturber distance.

Metastable oxygen atom detection using rare gas matrices

“…The concept of using excimer formation in a solid rare gas matrix to shorten the lifetimes of metastable atoms goes back to the earlier work where small quantities of oxygen containing molecules were frozen out in solid deposits of rare gases and then bombarded with electrons or energetic photons (Taylor et al 1981, Schoen and Broida 1960, Lawrence and Apkarian 1992, Maillard et al 1983, Girardet et al 1986, Goodman et al 1977. The mechanisms which governed the processes involved were well studied and understood.…”

“…In the present set-up we used a plexiglass light pipe between the cold finger and the photomultiplier to enhance the detection efficiency in the visible and near infrared regions and, since this does not transmit in the UV, we currently can not study the CO* excimers which radiate at 325 nm [see ] and which might be produced from targets such as CO or CO2. The concept of using excimer formation in a solid rare gas matrix to shorten the lifetimes of metastable atoms goes back to earlier work where small quantities of oxygen containing molecules were frozen out in solid deposits of rare gases and then bombarded with electrons or energetic photons , , Schoen and Broida (1960), Lawrence and Apkarian (1992), Maillard et al, (1985), Girardet et al (1986), Goodman et al (1977), Belov and Yurtaeva (2001)]. The mechanisms which governed the processes involved were well studied and understood.…”

Electron impact dissociation of N2O and CO2 with single particle detection of O(1D2)

“…The evolution of the technique of using excimer formation in a solid rare gas matrix to shorten the lifetimes of metastable atoms has its genesis in earlier work where small quantities of oxygen containing molecules were frozen out in solid deposits of rare gases and then bombarded with electrons or energetic photons [11][12][13][14][15][16][17][18]. The mechanisms which governed the processes involved were well studied and fairly well understood.…”

Detection of Metastable Atoms and Molecules using Rare Gas Matrices

“…In 1948, Vegard and Kvifte realized that green line emission, observed when a small oxygen impurity was present in a solid N 2 : Ar mixture, was due to the O( 1 S-1 D) transition. There have been many examples of this matrix isolation spectroscopy using both electron and photon bombardment (e.g., Belov and Yurtaeva, 2001;Belov et al, 2000;Fournier et al, 1982;Girardet et al, 1986;Goodman et al, 1977;Lawrence and Apkarian, 1992;Maillard et al, 1982Maillard et al, , 1983Taylor et al, 1981;Walker et al, 1981). Yurtaeva et al (1990) obtained similar results.…”