Double foil assembly for a high pressure deuterium gas target

In the case of small cyclotrons the optimal neutron source for biomedical application is a high pressure deuteron gas target, but the increasing pressure is limited by the mechanical strength of the entrance foil. A double foil assembly was constructed using helium flow between the foils at half pressure of the target gas. Optimization efforts on the size, shape, material, thickness and cooling parameters of the foil system are reported. (D.Gy.) 4 refs.; 1 fig