Liquid Nitrogen Cryostat to Facilitate Isothermal Annealing Studies on Metals after Heavy-Particle Bombardment

A cryostat is described which has been developed for irradiating a number of small metal specimens with a high beam current of heavy particles at liquid nitrogen temperature. The specimens, which are mounted on a block, are taken out of the cryostat after irradiation and subsequently annealed in a temperature bath. The progress of annealing is followed by measuring the change in electrical resistivity of the specimens in liquid helium.