Narrowing of the bennett hole in collisional plasma

The profile of a Bennett hole, induced by a laser field, in the ionic distribution of a collisional plasma is calculated. The influence of Chandrasekhar's dependence of the coefficients of velocity space transport on the profile is included in the calculation for the first time. It is found that the hole narrows down as the field-detuning frequency increases. The physical cause for this effect is the falling dependence of the Coulomb collision frequency on the ionic velocity. Estimations show that the effect is quite observable under conditions of a high-current gas-discharge plasma.