Vaycheslav M. Migel

The “Progress-P” 30 TW picosecond Nd:glass facility

Chirped pulse amplification was implemented in one of six amplifier chains “Progress” phosphate Nd:glass laser system. Laser system configuration and performance are presented. Formation of 300 ps chirped pulse at 1053 nm with energy up to 1 J is made by using developed starting laser which consists of Nd:YLF oscillator, optical fiber, stretcher and three amplifiers with output aperture 20 mm. The large amplifier chain of the laser system includes three rod amplifiers with the aperture of output rod of 85 mm. Preliminary experiments have been carried out yielding output chirped pulses of up to 55 J and compression them to 1.5 ps by grating compressor.

Methods and control-driving devices for high-precision remote alignment of multichannel high-power laser facility

The results of work on creation of a system for remote control alignment of high-power multichannel Nd·glass laser systems, being created in VNIIEF and NlffiF A, are presented. Methods and principles of alignment, high·accuracy driving units for mirrors tilts and pinholes travels, CCD-sensor capable of accepting weak radiation fluxes with a wavelength A.=l,053 μmare considered.

Absorption and transformation of laser energy in picosecond laser-plasma experiments at intensity of 10 16 to 10 19 W/cm 2

The interaction of a 1053 nm picosecond laser pulse with a solid target for focused intensities of up to 1019 W/cm2 are studied by measurements of the absorption of the laser light in the plasma and by measurements of the production of hard x-rays. Absorption measurements are made by collecting the scattered light in set of calorimeters. Light scattered in backward and specular directions is collected separately. Measurements are presented for both high and low Z targets. Hard x-ray spectrum in range 15-1000 keV and hot electron production in range 1-22 MeV are measured using a multichannel filter/scintillator and filter/semiconductor spectrometers. Spatial parameters of fast ions are studied.

Formation of high-contrast laser pulses on multiterawatt laser facility PROGRESS-P

We present the key features of design and performance of PROGRESS-P CPA Nd:YLF/Nd:glass laser facility capable of producing 1.5-ps pulses and a power up to 30 TW at the wavelength 1053 nm for laser- plasma experiments in ultrahigh irradiance on the target up to 1019 W/cm2. We describe voltage pulse drivers based on drift step recovery diodes which produce output voltage up to 15 kV, rise time approximately 1 ns, jitter of 100 ps and repetition rate up to 10 kHz to electro-optical devices.

30 TW laser facility “Progress-P”

Chirped pulse amplification was implemented in one of six amplifier chains “Progress” phosphate Nd:glass laser system. Laser system configuration and performance are presented. Formation of 300ps chirped pulse at 1053 nm with energy up to 1 J is made by using developed starting laser which consists of Nd:YLF oscillator, optical fiber, stretcher and three amplifiers with output aperture 20 mm. The large amplifier chain of the laser system includes three rod amplifiers with the aperture of output rod of 85 mm. Preliminary experiments have been carried out yielding output chirped pulses of up to 45 J and compression them to 1.5 ps by grating compressor.

Performance of the high-power PROGRESS Nd:glass laser facility

We present performance of PROGRESS Nd:glass laser facility which consists of a six beam PROGRESS-M phosphate Nd:glass laser, 30 TW PROGRESS-P picosecond YLF:Nd glass laser, which uses chirped pulse amplification (CPA) technique and target chamber. Laser is capable to focus simultaneously at 1,054 micrometer the energy of 1.5 kJ in 1.5 ns and power of 3.5 TW in 200 ps on the fusion target. We report performance of a single beam 0.5 kJ PROGRESS-1M laser. This laser with output rod amplifier 14 cm is the prolongation of one of the beam of the multi-beam laser. PROGRESS-P CPA laser uses YLF:Nd oscillator, single mode optical fiber, Nd:glass rod amplifiers with output diameter of 85 mm. At the output, the chirped pulse with energy about 45 J is compressed up to 1.4 ps in the single-pass compressor on two holographic gratings, which produces power of 22 TW.

High-power PROGRESS Nd:glass laser facility

We present performance of PROGRESS Nd:glass laser facility which consists of a six beam phosphate Nd:glass laser, 30 TW PROGRESS-P picosecond YLF:Nd glass laser, which uses chirped pulse amplification technique and target chamber. PROGRESS-M laser is capable to focus simultaneously at 1,054 micrometers the energy of 1.5 kJ PROGRESS-1M laser. This laser with output rod amplifier 14 cm is the prolongation of one of the beam of the multi-beam laser. PROGRESS-P CPA laser uses YLF:Nd oscillator, single mode optical fiber, Nd:glass rod amplifiers with output diameter of 85 mm. At the output, the chirped pulse with energy about 45 J is compressed up to 1.4 ps in the single-pass compressor on two holographic gratings, which produces power of 22 TW.

Spatial and spectral parameters of superthermal particle extension in laser plasma experiments with a picosecond laser pulse

On the PROGRESS laser facility the spectral and spatial characteristics of suprathermal particles extension in experiments with flat targets and picosecond duration of heating laser pulse are investigated. The opportunity to use multiframe pulse interferometry for visualization of spatial and power parameters of suprathermal particle extension alongside with traditional means of charged particle diagnostics with an irradiation of flat targets in an atmosphere of residual gas are considered. The basic part of laser radiation with energy up to 20 J and pulse duration 200 ps is directed to target chamber. A few parts of a heated laser pulse amplified and compressed with Raman backscattering compressor up to 10-20 ps with energy 20-30 mJ and wavelength 622 nm was used as optical diagnostic beam in multiframe interferometer. Series of experiments both with p and with the s-polarized radiation were carried out. On the basis of received interferograms the measurements of spectral parameters of fast particles by traditional methods with time-of-flight technique are carried out. This data are compared with spatial distribution of fast ions at picosecond laser-plasma experiments and laser intensity up to 1019 W/cm2 on the PROGRESS-P laser.

Focusing system of multiterawatt laser facility (PROGRESS-P)

Focusing of multiterawatt laser beams is of particular importance for super strong field experiments. The parameters of focusing system of 30-TW Nd: glass laser facility PROGRESS-P with chirped pulse amplification and result of experimental investigations of laser beam propagation through this system are presented. Near diffraction-limited beam quality is obtained at output laser amplifier chain by use of the low-thermal phosphate Nd:glass and high quality optical elements. Output 180 mm beam is compressed to 1.5 ps using two holographic gratings with dimensions 420 X 210 mm, injected in target chamber through the LiF-window with low nonlinear refractive index coefficient and focused to targets by means developed f/1.1 on-axis parabolic mirror with focal length of 200 mm. Over 50 percent energy is obtained in 6-7 micrometers focal spot in target chamber for low power beam. Determination of the focal spot dimensions for 10 TW beam from x-ray plasma image show that microspot diameter not exceeds 7 micrometers .

Absorption and fast ion generation in TW-picosecond laser-plasma experiments

The interaction of high-intensity, picosecond, 1.06 μm laser pulses at peak intensity up to 4⋅1017 W/cm2 with solid metal targets is studied by measurements of the absorption and fast particle generation with Ulbricht sphere and time-of-flight charge collectors and X-ray spectrometer measurements. Measurements are presented for both s and p-polarization.