Shielding liquid helium from the influx of external heat in a nuclear radiation field

Abstract

Specimens at the temperature of liquid helium are irradiated in a reactor by providing a cryochannel with cyrogenic machines [i, 2] one of which produces liquid helium, which is poured into the cryochannel, while the other produces gaseous helium at 10-20 deg K, which cools the cryochannel screens. In certain cases, it is more convenient and advantageous to use a relatively simple cryochannel with liquid helium which is brought in, all the more so as it becomes possible to reduce considerably the influx of external heat to liquid helium by using its vapor produced by additional vaporization of liquid helium from the unavoidable heat release in the liquid helium container in a nuclear radiation field.