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Title: Contamination spike simulation and measurement in a clean metal vapor laser

Abstract

This paper describes a new method for the generation of contamination-induced voltage spikes in a clean metal vapor laser. The method facilitates the study of the characteristics of this troublesome phenomenon in laser systems. Analysis of these artificially generated dirt spikes shows that the breakdown time of the laser tube is increased when these spike appear. The concept of a Townsend discharge is used to identify the parameter which changes the breakdown time of the discharges. The residual ionization control method is proposed to generate dirt spikes in a clean laser. Experimental results show that a wide range of dirt spike magnitudes can be obtained by using the proposed method. The method provides easy and accurate control of the magnitude of the dirt spike, and the laser tube does not become polluted. Results based on the measurements can be used in actual laser systems to monitor the appearance of dirt spikes and thus avoid the danger of thyratron failure.

Authors:
 [1];  [2]
  1. (Inst. of Aeronautics and Astronautics, Cheng Kung Univ., Tainan (TW))
  2. (Dept. of Electrical Engineering, Cheng Kung Univ., Tainan (TW))
Publication Date:
OSTI Identifier:
6944687
Resource Type:
Journal Article
Resource Relation:
Journal Name: IEEE Transactions on Instrumentation and Measurement (Institute of Electrical and Electronics Engineers); (USA); Journal Volume: 39:2
Country of Publication:
United States
Language:
English
Subject:
42 ENGINEERING; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; LASER MATERIALS; IMPURITIES; METAL VAPOR LASERS; FREQUENCY CONTROL; BREAKDOWN; IONIZATION; PARAMETRIC ANALYSIS; SIMULATION; THYRATRONS; CONTROL; ELECTRON TUBES; GAS DISCHARGE TUBES; GAS LASERS; LASERS; MATERIALS; 426002* - Engineering- Lasers & Masers- (1990-); 640410 - Fluid Physics- General Fluid Dynamics

Citation Formats

Lin, C.E., and Yang, C.Y. Contamination spike simulation and measurement in a clean metal vapor laser. United States: N. p., 1990. Web. doi:10.1109/19.52522.
Lin, C.E., & Yang, C.Y. Contamination spike simulation and measurement in a clean metal vapor laser. United States. doi:10.1109/19.52522.
Lin, C.E., and Yang, C.Y. 1990. "Contamination spike simulation and measurement in a clean metal vapor laser". United States. doi:10.1109/19.52522.
@article{osti_6944687,
title = {Contamination spike simulation and measurement in a clean metal vapor laser},
author = {Lin, C.E. and Yang, C.Y.},
abstractNote = {This paper describes a new method for the generation of contamination-induced voltage spikes in a clean metal vapor laser. The method facilitates the study of the characteristics of this troublesome phenomenon in laser systems. Analysis of these artificially generated dirt spikes shows that the breakdown time of the laser tube is increased when these spike appear. The concept of a Townsend discharge is used to identify the parameter which changes the breakdown time of the discharges. The residual ionization control method is proposed to generate dirt spikes in a clean laser. Experimental results show that a wide range of dirt spike magnitudes can be obtained by using the proposed method. The method provides easy and accurate control of the magnitude of the dirt spike, and the laser tube does not become polluted. Results based on the measurements can be used in actual laser systems to monitor the appearance of dirt spikes and thus avoid the danger of thyratron failure.},
doi = {10.1109/19.52522},
journal = {IEEE Transactions on Instrumentation and Measurement (Institute of Electrical and Electronics Engineers); (USA)},
number = ,
volume = 39:2,
place = {United States},
year = 1990,
month = 4
}
  • The generation of dirt spikes in the discharge of a clean pulsed metal vapor laser is measured under various operating conditions, such as a change in pulse repetition rates, laser tube temperatures, buffer gas pressures, and charging voltages. It is shown that the dirt spikes will increase in magnitude for such conditions that the pulse repetition rate decreases, the laser tube temperature decreases, and the buffer gas pressure increases. The ratio of the dirt spike to the charging voltage will also increase as the charging voltage decreases. All experimental results are well explained by theoretical analyses. These results lead tomore » a number of useful suggestions for the operation of a pulsed metal vapor laser.« less
  • In the room-temperature metal vapor laser studied, a rapid flow of noble gas entrains sputtered metal atoms, metal ions, and gas ions into the laser discharge volume in the form of a narrow jet. A short rise-time discharge pumps the laser transition and is observed to concentrate onto the preionized metal vapor jet. Radial and axial measurements of the electron temperature and ion number density in the preionized jet have been made using an instantaneous triple probe, and show that the ions are concentrated within the jet and extend up to about 20 cm downstream from the sputtering cell. Electronsmore » are carried along the jet by an axial ambipolar field, and are most energetic at the boundary of the jet where they are heated through three-body recombination. Under certain conditions, flowing gas through the sputtering glow discharge causes the plasma to oscillate with a period of between 2 and 20 ..mu..s. These oscillations are due to plasma instabilities associated with the anode glow, and have been eliminated by a suitable arrangement of the discharge electrodes. In so doing the anode glow has been extinguished, the slope resistance of the sputtering discharge reduced, and the performance of the sputtering cell improved.« less
  • Laser oscillation has been observed on the copper 510.6-nm (/sup 2/P/sub 3//sub ///sub 2/-/sup 2/D/sub 5//sub ///sub 2/) transition. A YAG laser is used to produce the metal vapor by irradiating a metal plate, and the metal atoms are excited by pulsed discharge.