Development of neutron beam analytical techniques for characterization of carbon fiber composite materials

The cold neutron prompt gamma ray activation analysis (PGAA) facilities at the University of Texas at Austin (UT) Nuclear Engineering Teaching Laboratory (UTNETL) have been used to characterize properties of advanced, carbon-fiber reinforced, epoxy-matrix composite materials. A method was developed using PGAA to measure the carbon fiber volume of different sample coupons. PGAA was also used to quantify amounts of water absorbed and desorbed from sample coupons. In support of these measurements, the PGAA facilities were optimized for the handling of unique composite samples. In particular, neutron and gamma shielding was reconfigured to minimize interference and background noise, and sample holders were designed to maximize radiative capture reaction rates within test samples. To allow quantitative calculations to be made, the temporal and spatial variations in the guided and focused cold neutron beam were characterized. The results of this investigation demonstrate the use of PGAA as a tool for the non-destructive analysis of advanced composite materials.