Positron annihilation studies of moisture in graphite-reinforced composites

Journal Article · Tue Jul 01 00:00:00 EDT 1980 · Ceram. Eng. Sci. Proc.; (United States)

DOI:https://doi.org/10.1002/9780470291030.ch15· OSTI ID:5691453

Singh, J J ^[1]; Holt, W H ^[2]

---

1. NASA, Langley Research Center, Hampton, Va.
2. U.S. Navy, Naval Surface Weapons Center, Dahlgren, Va.

The positron lifetime technique of monitoring absorbed moisture is applied to several composites, including graphite/polymides which are candidates for high-temperature (over 260 C) applications. The experimental setup is a conventional fast-slow coincidence system wherein the positron lifetime is measured with respect to a reference time determined by the detection of a nuclear gamma ray emitted simultaneously with the positron. From the experiments, a rate of change of positron mean lifetime per unit mass of water can be determined for each type of specimen. Positron lifetime spectra are presented for a graphite/polyimide composite and for a pure polyimide.

• OSTI ID: 5691453
• Report Number(s): CONF-780181-; CONF-790194-
• Journal Information: Ceram. Eng. Sci. Proc.; (United States), Vol. 1; Conference: 2. American Ceramic Society annual conference on composites and advanced materials, Cocoa Beach, FL, USA, 22 Jan 1978
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COMPOSITE MATERIALS
MOISTURE
POSITRONS
EPOXIDES
GRAPHITE
ANNIHILATION
ADSORPTION
DECAY
NONDESTRUCTIVE TESTING
ANTILEPTONS
ANTIMATTER
ANTIPARTICLES
BASIC INTERACTIONS
CARBON
ELECTROMAGNETIC INTERACTIONS
ELEMENTARY PARTICLES
ELEMENTS
FERMIONS
INTERACTIONS
LEPTONS
MATERIALS
MATERIALS TESTING
NONMETALS
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
SORPTION
TESTING
360304* - Composite Materials- Physical Properties- (-1987)