224 CM Variable Energy Cyclotron at Calcutta

Progress of work on the construction of the 224 cm. Variable Energy Cyclotron, being installed at Calcutta is described. The cyclotron, with maximum expected energies of 70 MeV protons, 65 MeV deuterons and 130 MeV alphas, follows the design of the 88¿ cyclotrons at the Lawrence Berkeley Laboratory and the Texas A & M University, with some modifications incorporated for facilitating indigenous fabrication and for improved performance. The yokes and yoke legs of the 250 tonne magnet have been cast and tested for composition and porosity. The machining of yokes, yoke legs and pole pieces is under way. The main coil winding has started. The trim and valley coils will be epoxy potted. The rf system, utilising the RCA 6949 oscillator tube, is a combination of a self-excited and a driven system. Power supply fabrication is nearing completion and two 89 cm diffusion pumps have been fabricated for the vacuum system. The building is in the final stages. Beam transport layout envisages three high intensity and six high resolution channels. A small 8k on-line computer is being planned. Various other facilities are also being planned.