arXiv subjects

I. Mogentale

Publications and source records attributed to I. Mogentale.

3 recordsLinked to original sources

arXiv2007

Low- and high-density features of IR luminescence of Xe$_{2}$ excimers produced by electron impact

Electron--impact excitation of Xe atoms in pure Xe gas and in a Xe(10 %)--Ar(90 %) mixture has led to the discovery of infrared (IR) luminescence of Xe$_{2}$ excimers. The investigation of the emission spectrum at low gas density has allowed the identification of the molecular states involved in the transition. When the gas density is increased to values up to 40 times larger than the density of the ideal gas at standard temperature and pressure, the interaction of the excimer with the dense environment produces a strong red--shift of the spectrum that is interpreted in terms of many--body effects.

physics.atom-ph↗

arXiv2007

Infrared emission spectrum and potentials of $0_u^+$ and $0_g^+$ states of Xe$_2$ excimers produced by electron impact

We present an investigation of the Xe$_{2}$ excimer emission spectrum observed in the near infrared range about 7800 cm$^{-1}$ in pure Xe gas and in an Ar (90%) --Xe (10%) mixture and obtained by exciting the gas with energetic electrons. The Franck--Condon simulation of the spectrum shape suggests that emission stems from a bound--free molecular transition never studied before. The states involved are assigned as the bound $(3)0_{u}^{+} $ state with $6p [1/2]_{0}$ atomic limit and the dissociative $(1)0_{g}^{+}$ state with $6s [3/2]_{1}$ limit. Comparison with the spectrum simulated by using theoretical potentials shows that the dissociative one does not reproduce correctly the spectrum features.

physics.atom-ph↗

arXiv2005

Environment influence on the IR fluorescence of Xe$_{2}^{*}$ molecules in electron beam excited Ar--Xe mixture at high density

We report new measurements of the near infrared (NIR) Xe$_2^*$ excimer fluorescence in an electron--beam--excited Ar (90%)--Xe (10 %) mixture at room temperature. Previous measurements up to a density $N\approx 2\times 10^{26}$ m$^{-3}$ discovered a broad excimer fluorescence band at $\approx 7800$ cm$^{-1},$ whose center is red--shifted by increasing $N$ (A. F. Borghesani, G. Bressi, G. Carugno, E. Conti, and D. Iannuzzi, {\em J. Chem. Phys.}, {\bf 115}, 6042 (2001)). The shift has been explained by assuming that the energy of the optical active electron in the molecule is shifted by the density--dependent Fermi shift and by accounting for the solvation effect due to the environment. We have extended the density range up to $N\approx 6\times 10^{26}$ m$^{-3}, $ confirming the previous measurements and extending the validity of the interpretative model. A detailed analysis of the width of the fluorescence band gives a value of 2.85 nm for the size of the investigated excimer state. Such a large value lends credence to the validity of the proposed explanation of the experimental findings.

physics.atom-ph↗