Background Gas Pressure Dependence of Unipolar Arcing on Soda Lime Glass and Plastic Induced by a CO2 Pulsed Laser
Abstract
An experiment was conducted to determine the background gas pressure dependence of laser induced unipolar arcing (UA) on soda lime glass and polystyrene (plastic). A carbon dioxide pulsed laser was used to produce a power density of 5,2500,000 W/sq. cm., and the background pressure was varied from 1.0 atmosphere (atm) to 10 to the 8th atm (approx .000001 torr). For glass at 1.0 atm, the VA crater density at the damaged area's center was maximum and between 1.0 and 0.1 atm, it decreased linearly as the pressure dropped. UA did not occur outside of the heavily damaged area. Between 0.1 and 0.001 atm, UA occurred outside the heavily damaged area. Between 0.1 and 0.001 atm, VA occurred outside the heavily damaged area and both the center and perimeter crater density remained constant. A wave-like ring burn pattern was observed showing the influence of plasma dynamics on the laser beam propagation. Below 0.001 atm, the UA increased at the perimeter and target center, and peaked at approximately 0. 0005 atm. The crater density remained constant for lower pressures. A proposed model for this interaction is outlined. Laser damage, Theses.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1988
- Accession Number
- ADA200944
Entities
People
- Adam R. Wojtowich
Organizations
- Naval Postgraduate School