3.03 The Central Region Model Cyclotron

This full-scale model of the first stages of acceleration (to 2.5 MeV) was built to test the sometimes unconventional engineering concepts of the various technical systems - ion source, beam transport, magnet, rf acceleration, vacuum and controls.

The relatively small magnet is at centre right, with the platform above carrying the injection beamline from the H- ion source (off right). The vacuum chamber extends way outside the magnet to both left and right, in order to accommodate the quarter-wave (3.25-m long) cavities providing the accelerating voltage.

In fact no significant problems arose, and beam was successfully accelerated to 2.5 MeV in June 1972, and to full 100 μA intensity a year later.

While the entire assembly was eventually dismantled, the magnet coils, magnet power supplies and numerous ISIS beamline components are still on site and many items are still in use.