Electron-beam-excited high-pressure He – Ar mixture as a potential active medium for an optically pumped laser

The possibility of developing a laser with optical pumping of metastable ArI levels produced by a relativistic electron beam in high-pressure He – Ar gas mixtures is investigated. It is shown that a high population of the 1s₅ level of the argon atom, a wide (~10 nm) absorption spectral line, and a great lifetime allow us to obtain, as a result of electron beam impact, optimal lasing conditions within the framework of the classical three-level laser scheme. The rate constants of two- and three-particle collisional relaxation processes of low-lying 4s levels of an excited argon atom in He – Ar mixtures in the pressure range from 4 to 0.75 atm are measured.