Experimental study on an all gas-phase iodine laser using microwave discharge of Cl2/He as a Cl atoms source.
Microwave discharge of a Cl2/He mixture as a simple, clean and efficient Cl atom generator was used for an all gas-phase iodine laser study. Sufficient NCl(a1Delta) was produced through the reaction of HN3+2Cl-->NCl(a1Delta)+HCl+N2. The energy transfer reaction of I(2P3/2)+NCl(a1Delta)-->I(2P1/2)+NCl(X3Sigma) was observed. A population inversion was observed directly by using a 1315 nm tunable diode laser by scanning the entire line shape of the (3,4) hyperfine transition of iodine, and a small signal gain of 5x10(-5) cm-1 was obtained.
The measurement of gain in a supersonic, combustion-driven generator for NCl(a1Δ)
The measurement of positive small signal gain on the 1.315 micron spin orbit transition of atomic iodine following energy transfer from chemically generated NCl(a1Δ) is reported. Previous instances of gain produced by energy transfer from NCl(a1Δ) used DC discharges to generate F and Cl atoms; this report describes recent progress towards a true chemical laser device which uses a high temperature chemical combustor and a supersonic reactor to generate NCl(a1Δ). These improvements represent a significant step towards the development and demonstration of a scalable All Gas-phase Iodine Laser (AGIL) device.
Effects of low air pressure on AC and DC arc propagation on ice surface
The effects of air pressure on the AC and DC arc process on an ice surface, including velocity, parameters and flashover voltage, were studied. The results obtained showed that air pressure has an obvious influence on the arc propagation velocity, arc constant A, electrode voltage drop Ve and consequently on the flashover voltage of the ice surface, Vf. This decrease in Vf is explained by the decrease in the E-I arc characteristics and arc propagation velocity, and by the relatively higher density of Na atoms in the arcs at pressures below standard air pressure. Based on these results, the mechanism underlying the decrease in the flashover voltage of ice-covered insulators at high altitude was analyzed