Positron Annihilation Studies of Thermoplastic LCP Composites,
Abstract
The time dependent decrease in orthopositronium (o-Ps) intensity detected in polymers during long term positron annihilation lifetime (PALS) experiments has been extensively studies and modeled. This decrease in temperature dependent, polymer specific, source strength dependent and is noted to saturate as a function of source exposure time. Larger decreases and smaller saturation values are exhibited at lower temperatures. Additionally, at sufficiently high temperatures, a negligible decrease is detected. The time dependent decrease is recoverable at elevated temperatures. In contrast, the o-Ps lifetime component remains constant and independent of exposure time. Increasing the exposed sample volume by continuously varying the source-sample orientation dramatically decreases the reduction of o-Ps intensity.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 03, 1995
- Accession Number
- ADA299436
Entities
People
- Phillip L. Jones
- Robert A. Naslund
Organizations
- Duke University