Excited Argon 1s5 Production in Microhollow Cathode Discharges
Abstract
Diode-pumped rare gas lasers (DPRGL) have been in development for their potential to become high energy lasers with excellent beam quality that is typical of gas lasers. DPRGL require metastable densities on the order of 10^13 cm^-3 at pressures around one atmosphere for efficient operation. Argon 1s5 number densities have been measured in microhollow cathode discharges (MHCD) using tunable diode laser absorption spectroscopy. The MHCDs had gaps of 127 and 254 m and hole diameters from 100-400 m. Absorbance was measured at pressures of 37 Torr up to 400 Torr, where absorbance could no longer be detected. Fluorescence images revealed the plasma formation was inconsistent and often not in line with the hole, making path length determinations difficult. Assuming a path length equal to the total plate thickness of either 198 or 325 m resulted in the maximum possible Ar 1s5 number densities, ranging from 0.55-4.0 x 10 ^13 cm^-3. The actual number densities could be three times lower depending on the actual path length. There were no consistent trends with hole diameter, gas pressure, or gap distance.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 2018
- Accession Number
- AD1056265
Entities
People
- Richard D. Peterson
Organizations
- Air Force Institute of Technology