The Nitrogen Ion Laser
Abstract
The characterization and thermal scaling of the nitrogen ion laser pumped by charge transfer from He2(+) is reported in this work. Intense laser emission in the violet at 427 nm has been observed and found to have a linewidth less than 0.3A. The pumping ion, He2(+), was produced by discharge of a fast- pulsed electron beam gun, APEX-1, into several atmospheres of a mixture of helium and nitrogen. Excitation current densities ranged from 1.1 to 2.5 KA/sq cm at 1 MV over a 1 x 10 cm transverse geometry. Under these conditions the efficiency of the emission of 427 nm laser radiation was found to be proportional to the total pressure raised to the 1.2 power. Efficiencies of 1. 6% relative to the energy lost by the electron beam in the radiating volume have been achieved in volumes of 16 cc at room temperature. Outputs of 35 mJ have been obtained from the 16 cc working volume at 30 atm pressure under these conditions. Thermal scaling of the laser has been investigated and a strong inverse dependence of laser has been investigated and a strong inverse dependence of laser output on gas temperature was observed. At -20C the output was found to increase to 80 mJ form the same volume containing helium at a density giving a pressure of 35 atm. at room temperature. This corresponded to an output efficiency of 3% relative to the energy deposited by the electron beam. Quasi-cw operation was achieved under these conditions suggesting that much longer output pulses might be obtained with an e-beam pulse of greater duration.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 31, 1977
- Accession Number
- ADA039506
Entities
People
- Carl B. Collins
Organizations
- University of Texas at Dallas