External Target Irradiation for the Princeton University A. V. F. Cyclotron

A comparatively simple and inexpensive facility is being completed to irradiate targets in the external beam of the Princeton A. V. F Cyclotron. The target can be removed and used relatively quickly. The target itself is held and cooled by a version of the Berkeley 88" Cyclotron target holder block, which also acts as a beam stop. We estimate on the basis of our calculations and Berkeley\´s experience that the block will easily handle the 3.36 kW we expect to deliver with a 60 ??A beam of 56 MeV protons or similar beams of other ions. The target holder block is lowered into a vacuum chamber on a supporting column which provides the block with cooling water and electrical leads for monitoring. The chamber is surrounded by shielding to attenuate fast neutrons during bombardment and to protect personnel handling the block afterwards. After irradiation the block is purged of water, vacuum is broken, and the block is lowered into a lead cart through a gate valve at the bottom of the facility. The block is then taken to a shielded handling area, where it can be disassembled quickly.