High-current Electric Discharge Research Articles

Blue-green laser emission from IF subjected to wide-band optical pumping

Lasing at 485–491 nm was observed from the interhalogen compound IF which was formed by excitation of an NF3–CF3I–Ar mixture with vacuum ultraviolet radiation from a high-current electric discharge. The energy of laser pulses was 42 mJ and the duration of these pulses was 4 μ sec.

Generation and amplification of nanosecond pulses by iodine lasers

Results are reported of experimental investigations of high-power photodissociation iodine laser pumped by lamps and by radiation from high-current electric discharges. The basic parameters of the working medium, the parameters of both lamp-pumped and discharge-pumped lasers, and methods of shaping of a short pulse with diffraction directivity of the radiation are investigated. The possibility of effective amplification of a short pulse by an iodine amplifier pumped with an open high-current discharge is demonstrated. An iodine laser generating a pulse of duration I nsec, divergence 10-4 rad, and energy 100 J at a contrast 108 and 300 J at a contrast 102–103 is described.

Method of indirect determination of the anodic and cathodic voltage drops in short high-current electric discharges in a dielectric liquid

The removal of electrode material by electric discharges in a dielectric liquid is usually performed with a short interelectrode gap (about 50 μm) and short discharge durations (20–2000 μs). It is therefore virtually impossible to measure the anodic and cathodic voltage drops of such discharges. However, considering that there is a direct relation between the amount of electrode material removed and the electric energy provided in the anodic (or cathodic) region, an indirect determination of those voltage drops is obtained by comparison of experimental results concerning mass loss at the electrodes and the molten volume computed after a linearized heat-conduction model. The results obtained are in agreement with the measured value of the total interelectrode voltage drop.

Ultimate characteristics of an XeO photochemical laser

An expenmental and theoretical investigation is made of the nature of internal losses in the active medium of an XeO photochemical laser pumped by an open high-current electric discharge. It is shown that the specific efficiency of an XeO laser may be enhanced by reducing the internal losses. Calculations are made of the pumping and the predicted output energy from an XeO laser with a plane-mirror resonator is determined. The optimal mixture composition and transmission of the mirrors are found for which the output energy in pulses of ~ 10 ? sec duration should be ~ 40 J, corresponding to a total laser efficiency of ~ 0.1 %. It is noted that the efficiency of this laser may be further improved to 0.2% by using isotopically pure xenon.

Iodine photodissociation laser pumped by radiation from a high-current discharge with a return current conductor

An investigation was made of the energy, spectral, and angular characteristics of the radiation emitted by an iodine photodissociation laser (pumped by a high-current electric discharge with a return current conductor) utilizing CF3I–CO2 or CF3I–SF6 mixtures diluted with Xe, Kr, Ar, and He. It is shown that when the rate of coupling of the electric energy into the discharge is moderately low, the radiation energy, optical inhomogeneities of the active medium, and domain of existence of high grad n depend on the ratio of the molecular weight of the mixture to the number of atoms per molecule. When the refractive index gradients of the active medium are large, the divergence of the laser radiation is mainly governed by grad n in this zone and depends weakly on the resonator length.

Exploding Wire as Fast Dynamic Pinch

The high-current electric discharge through fine wires is studied under experimental conditions in which the interaction of the discharge with its self-magnetic field is dominant. When the wire is composed of an element or elements of low atomic number, the discharge is found to have many of the characteristics of pinch discharges in gases. A capacitor bank of 1.75 μf and a voltage rating of 100 kv was used with a switching spark gap and circuit of very low parasitic inductance. The parasitic inductance of the condensers and circuit was measured to be 0.05 μh while the ringing frequency of the discharge was 370 kc. Wires of copper, aluminum, polyethylene, lithium, and lithium-lithium hydride were exploded. The discharge was photographed with streak and framing cameras and oscillograms taken of the discharge current and its time rate of change. Wires composed of lithium-lithium deuteride were observed to give neutron yields of the order of 106 per shot. The neutron yields were measured with a silver-foil activation counter.