The effects of exchange gas temperature and pressure on the beta-layering process in solid deuterium-tritium fusion fuel

✍ Scribed by James K. Hoffer; Larry R. Foreman; John D. Simpson; Ted R. Pattinson

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 190 KB
• Volume: 165-166
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/s0921-4526(90)80931-8

✦ Synopsis

It has recently been shown that when solid tritium is confined in an isothermal enclosure, self-heating due to beta decay drives a net sublimation of material from thick, warmer layers to thin, cooler ones, ultimately resulting in layer thickness uniformity. We have observed this process of "beta-layering" in a 50-50 D-T mixture in both cylindrical and spherical enclosures at t e!? eratures from 19.6 K, down to 11.6 K. The measured time constants are found to depend on the He content as suggested by recent theoretical predictions. When using an enclosure having low thermal conductivity, the ultimate layer uniformity is found to be a strong function of the exchange gas pressure. This is due to the presence of thermal convection in the exchange gas and consequent temperature anisotropy at the solid layer surface.