Excitation Mechanism of 3250 and 4416 Å Laser Lines in the Cataphoretic He-Cd Laser Discharge
Abstract
The hook method has been applied to the population measurement for low-lying excited levels of He and Cd including metastable levels as well as for the ground state of Cd in the cataphoretic He-Cd laser discharge (3 mm bore and 685 mm long) under the typical condition for lasing (He pressure of 4.0 Torr, evaporator temperature of 170 to 270°C and dc current of 30 to 160 mA). The population density of Cd ions in the 3250 Å upper level was also obtained by the line intensity measurement combined with the hook method. The results have shown that Penning collisions of ground state Cd atoms with 23S metastable He atoms are dominant for the excitation of 4416 and 3250 Å laser lines. The Penning-excitation cross section of 1.7× 10-15 cm2 and the population density of the 4416 Å upper level have been determined, which are consistent with the result so far obtained.
- Publication:
-
Japanese Journal of Applied Physics
- Pub Date:
- November 1974
- DOI:
- 10.1143/JJAP.13.1866
- Bibcode:
- 1974JaJAP..13.1866M
- Keywords:
-
- Atomic Excitations;
- Electric Discharges;
- Electrophoresis;
- Gas Lasers;
- Laser Outputs;
- Line Spectra;
- Atomic Energy Levels;
- Cadmium;
- Ground State;
- Helium;
- Metal Vapors;
- Penning Effect;
- Population Inversion;
- Ultraviolet Radiation;
- Lasers and Masers