Hot-electron thermalization in solid and liquid argon, krypton, and xenon

An Analysis of Electron-Hole Recombination in Solid Xenon with Time-Resolved Luminescence Spectroscopy

“…Thermalization of`hot' electrons is slowed down dramatically compared to other insulators and semiconductors. This was demonstrated in, e.g., time-resolved transient conductivity measurements [10]. At T = 157 K, Sowada et al [10] observed a thermalization time t th = 4.4 ns.…”

“…This was demonstrated in, e.g., time-resolved transient conductivity measurements [10]. At T = 157 K, Sowada et al [10] observed a thermalization time t th = 4.4 ns. Taking into account that t th is proportional to Tm 0 (m 0 being the low field mobility) with m 0 proportional to T ± ±3/2 (scattering on acoustic phonons), the thermalization time at T = 5 K is of the order of 20 ns (this estimate is rough because other scattering mechanisms like scattering on defects and impurities speed up thermalization).…”

Ion-beam excitation of liquid argon

“…the electrons have already fully thermalized at the time of recombination. For LAr, thermalization times of less than 1 ns have been reported [43]. In principle, a recombination process can lead to either a molecule in a singlet or a triplet state.…”

“…In the liquid and solid phase this process is also referred to as self-trapping [4,41]. The typical time scale for the formation of excimer molecules in LAr is ps [42]; the thermalization of hot electrons takes several hundreds of ps [43], leading to recombination times in the ns range [42]. Direct radiative transitions of argon atoms in the lowest excited state to the ground state with photon energies corresponding to wavelengths of the resonance lines of 104.8 nm and 106.7 nm [44] are strongly suppressed in a dense medium.…”

Positron annihilation in simple condensed gases

“…However, the phase of each photon remains invariant between reference frames Using (B.4) and the usual Lorentz t ransformations for (ct , x) and (w* / c , k*) gives Appendix C. Thermafization Times in the Condensed Rare Gases 203 Table C.l: Thermalization times for eiectrons with an average initial kinetic energy of -10 eV in weakly scattering heavier condensed rare gases. Sowada et al ( 1982aSowada et al ( , 1982b measured the transient conductivity resulting from a high energy radiation pulse. Since the eiectron mobility is inversely proportional to the square root cf the thermal electron velocity, the slowing down of eiectrons increases the drift mobility and the conductivity.…”