On the possibility of laser generation without inversion on the fine-structure levels of a helium atom

Аннотация

It is shown that laser generation is possible in principle upon coherent excitation according to the V-scheme of the (1s2p)³P_j levels with j = 1, 2 of a helium atom from the (1s2s)³S₁ level of the same atom when the latter level is, in turn, populated by electron or proton impact.