Emission of the³He—Xe—Cd mixture in the active zone of a nuclear reactor

Abstract

We have determined the lifetimes of helium n 1 P states, from the shortest 2 1 P (560 ± 14 ps), up to the 10 1 P (59.8 ± 1.5 ns). The experiment was performed by measuring the time dependence of UV fluorescence after the resonant excitation of states with pulsed synchrotron light. The apparent lifetimes have been extrapolated to the zero gas pressure limit for each n. Cascade decays of the initially prepared states and the effect of periodic target excitation have been also considered. The results are compared with our MCHF calculations and with other theoretical and experimental values.

Mechanisms of level population in gas lasers pumped by ionizing radiation

“…The activity of the α sources was 9.6 GBq, which corresponds to an average energy deposition under 2 atm of helium of W ≈ 3 × 10 −5 Wcm −3 and a mean ionization rate according to gas volume of S ≈ 4 × 10 12 cm −3 s −1 . The apparatus for study of luminescence spectra of gas mixtures in the active zone of a nuclear reactor is described in Khasenov (2004;2014).…”

Optical Emission of the Nuclear-Induced Plasmas of Gas Mixtures

“…For the reactor research, gas mixtures were loaded into the core in vacuum-sealed glass ampoules, each of which had a window of radiation-resistant cerium glass [15]. The spectral range of measurement (350-830 nm) was determined by the transmission cut-off threshold of the window and the photomultiplier sensitivity.…”

“…The energy-level scheme of the cadmium atom is similar to that of mercury (Figure 3). Therefore, the study of the feasibility of quasicontinuous lasing at the 6s-5p transitions of Cd is of some interest [15]. The quantum-efficiency coefficient of such a system (the ratio of the photon energy to the energy required to form an electron-ion pair with Xe or Kr) is greater than 10%, which is notably higher than that of the cadmium-ion transitions in He-Cd mixtures.…”

Nuclear-Induced Plasmas of Gas Mixtures and Nuclear-Pumped Lasers

“…Luminescence of 3 He-Cd and 3 He-Xe-Cd mixtures in the radiation region of stationary nuclear reactor investigated in [113]. Measured value of rate constant of Xe 2 + charge exchange on cadmium atoms is small (~10 −13 cm 3 s −1 ), in contrast to the constant of charge exchange on mercury atoms.…”