Yu. A. Zakharenkov

Interaction of Powerful Laser Radiation With Shell Targets

The up-to-date experiments with solid and shell targets have evidenced the existence of high compression of the substance in the center of the target1-7. The ultimate compression and temperature are caused by the mechanisms of absorption and conversion of high-power laser radiation energy to the plasma energy, by the dynamics and stability of compression, and the processes occuring in plasma corona 8-11.

Determination of the imploded mass in laser-imploded shell targets

A new method of experimental measurement of the imploded mass of laser-imploded shell targets is proposed. This method is based on simultaneous measurements of the velocity spectrum of the neutral atom flux emitted from the imploded part of the target, and the total energy carried by them. A semiconductor diode with a shallowly located p – n junction was used as the low energy neutral particle detector. By means of the time of flight method neutral atom fluxes with velocities υ ∼ (0·6 − 1·8) × 10 7 cm/s were registered in experiments carried out on the 6-beam laser system “Delfin”.

Measurement of the dynamics of the compression of high aspect-ratio shell targets in the “Delfin-1” installation

Abstract With the help of a specific diagnostic system designed for the “DELFIN-1” installation we have measured implosion velocities ≳ 250 km/s, which are record values for experiments on compression at sufficiently high hydrodynamic efficiency of ablative shell targets. An empirical scaling is shown to agree well with the measured compression velocities.

Laser produced plasma refractometry

A method of probing beam refraction is suggested for the investigation of laser-produced plasma with high density gradients. The refraction angle a of a probing rayas a function of ray impact parameter p is used as input data. Different experimentalrealizations of a(p) measurements are considered. Results from laser produced plasmainterferograms processed with phase shift and refractometry methods are compared.1. IntroductionThe possibility of density profile reconstruction is considered in the case of oneimage projection of axisymmetric laser produced plasma with

Four‐channel x‐ray spectrometer on a transmission grating with a combined system of detection

We have developed a new soft x‐ray spectrometer covering the photon energy range of 50–500 eV. It employs a free‐standing transmission grating coupled to a microchannel‐plate detector (MCD). The performance of the device was tested by using radiation from a synchrotron with a continuous spectrum. The MCD shows a rather flat response over most of the useful spectral range, with an abrupt decrease in the sensitivity at the short‐wavelength end. Its simplicity of operation makes the device attractive for such applications as the study of soft x‐ray emission from laser‐produced plasmas.

Four-channel spectrometer on a transmission grating with combined system of detection

Abstract We have developed a new soft X-ray spectrometer covering the photon energy range 50–500 eV. It employs a free-standing transmission grating coupled to a microchannel-plate detector. The performance of the device was tested by using synchrotron radiation with a continuous spectrum. The detector shows a rather flat response over most of the useful spectral range, with an abrupt decrease in sensitivity at the short-wavelength end. Its simplicity of operation makes the device attractive for such applications as the study of soft X-ray emission from laser-produced plasmas.

Manyframe High Speed Schlieren Photography of Shock Waves in a Ruby Laser Beam

The method of seven—frame high speed schlieren photography in a ruby laser beam (λ= 0.69 μ) is described for the investigation of shock waves produced by the expanding laser plasma in the ambient gas. Exposition time of each frame was τ = 5.10−10 sec.