E. N. Abdullin

High-power excimer laser systems

Two-high power excimer laser systems with square (25 × 25 cm) and circular (with a diameter of 40 cm) cross sections of the output laser beam are described. The first (second) system consists of four (five) excimer lasers. The experimental results on the generation of the high-quality high-power laser pulses are presented. Laser beams with a pulse duration of 1–250 ns, a divergence of 0.01 mrad, a spectral line width of 0.01 cm−1, and a pulse energy of up to 330 J are obtained.

High-power wide-aperture electron-beam-pumped lasers on dense gases

Schemes of high-power electron-beam-pumped pulsed lasers on dense gases and the experimental results on the lasing on XeCl*, KrF*, and HF molecules are presented. The energy input and the kinetic processes in the active medium of the electron-beam-excited XeCl laser are calculated. Radiation pulse energies of 1900, 200, and 90 J are obtained at wavelengths of 308 nm, 2.8 μm, and 249 nm, respectively.

The development of a long-pulse excimer laser system

A 250 J/210 ns four-stage XeCl laser system named Photons has been developed. Five lasers in MOPA chains characterized by different pumping techniques are described. Also, the main experimental results of the Photons are given.

Generation of high-current large-cross-section electron beams in a vacuum diode with rod current returns

The results of experiments on obtaining high-current radially converging extended electron beams in a vacuum diode of an electron accelerator, which is intended for excitation of a gas laser, are presented. To reduce the magnetic field in the diode and its influence on the beam formation, in addition to magnetically shielding plates that sectionalize the diode into two magnetically shielded diodes, small-diameter rod current returns were used. Cathodes with wide concave emitting units, which provided a high degree of filling the output windows with the electron beam, were used. The rods are installed in holes between the emitting units and connect the cell ribs to the vacuum-chamber wall. A significant decrease in the angles of electron entry into the foil was observed. It is shown experimentally that mounting the current returns results in a decrease in the magnetic field in the diode, while breakdowns and a decrease in the electron-beam current-pulse duration are absent. At a diode voltage of 550 kV, electron beams with a current of 240 kA, a beam energy in the diode of 20 kJ, and an extracted-beam energy transported through the foil of 6.5 kJ were obtained. The possibility of increasing the electron-beam energy, which is transferred from the diode to the gas-filled cell, by a factor of at least 1.2 was demonstrated.

High-energy wide-aperture lasers pumped by radially convergent electron beams

The results of the experimental study of UV and IR lasers pumped by electron beams are presented. The accelerators with radially convergent electron beam for pumping gas mixtures under pressure up to 3 atm were used. Laser radiation energies of up to 2 kJ, 200 J, 100 J, 50 J have been obtained at the wavelengths of 308 nm, ~2.8 μm, 250 nm and 1.73 μm, 2.03 μm, correspondingly.

Experimental study on a long-pulse excimer laser system

A four-stage XeCl laser system named Photons has been developed for studying laser interaction with materials. The Photons are outlined and preliminary results characterizing the system are given. The master oscillator Photon-1 can provide “seed” light with laser energy of about 40mJ, pulse duration of about 250ns and good beam quality of nearly diffraction-limited divergence angle and narrow line width less than 1 cm-1 for whole system. The output energy of laser system of 251J has been obtained by four-stage amplification. The synchronization among five lasers is realized by the combination of low voltage timer, high voltage synchronic generators and compensated cables. The demonstration shows Photons good operation with low jitter of less than ±20ns.

Radiant energy distribution over the output beam cross-section for wide-aperture lasers excited with a radially convergent electron beam

The results are presented of experimental and theoretical investigations of excitation and generation of the HF laser pumped by nonchain chemical reaction initiated by a beam of electrons as well as of the KrF and XeCl lasers pumped by beams of electrons. The effect of the volume charge field on the distribution of energy over the cross section of a laser cell and of the radiant energy density over the cross section of an output laser beam in mixtures with different concentrations of halogen is analyzed. The output energy density distribution over the beam cross section for lasers excited by the radially convergent beam of electrons and the total pump energy are determined. The pump energy distribution over the laser cell cross section and the total pump energy in various gas mixtures are calculated.

Electron-beam-pumped broad-aperture lasers

The results of an experimental study of the laser action on XeCl*, KrF*, and N2 molecules and by the atomic transitions of xenon and neon are presented. Laser radiation energies of 110, 90, 3, 100, 50, and 0.5 J have been obtained at (lambda) equals 308, 249, 358, 1730, 2030, and 585 nm, respectively. The experiments were carried out on two accelerators producing radially convergent electron beams, that pumped laser chambers 20 mm in diameter with a beam current of FWHM duration 0.3, 30, and 100 microsecond(s) .