Characteristics of a pulse-periodic CO2 laser for applications in the field of laser-produced plasma

The design of a pulse-periodic DD2 laser oscillator that operates at a high level of the specific energy deposition into a self-sustained discharge is described. The laser is intended for generating pulses with a high-density radiation flux in a laser-plasma generator of multiply charged ions at the Institute of Theoretical and Experimental Physics (ITEP). The results of investigations of the spatiotemporal and energy characteristics of laser output radiation in a wide range of the discharge excitation level and the mixture composition are presented. The optimal conditions are determined under which the oscillator provides an output energy of > 10 J in a pulse with a duration of 28 ns and a record specific peak radiation power of 190 MW per liter of the active volume of a CO2: N-2: He mixture. The high quality of the spatial characteristics was confirmed in measurements of the radial energy-density distribution in the far-field zone, whose characteristic size is close to the diffraction limit.