• M. Ahammed, D. Adak, R.K. Bhandari, P. Bhattacharyya, J. Chaudhuri, M.K. Dey, A. Dutta Gupta, B. Hemram, B.C. Mandal, B. Manna, S. Murmu, H.K. Pandey, S. Saha, S. Sarkar, S.K. Singh, T. Viswanathan
  DAE/VECC, Calcutta

K500 Su­per­con­duct­ing Cy­clotron (SCC) is al­ready com­mis­sioned suc­cess­ful­ly at VECC, Kolkata by ac­cel­er­at­ing Ne³⁺ in­ter­nal beam with 70 nA beam cur­rent at 670 mm ex­trac­tion ra­dius. The Radio Fre­quen­cy cav­i­ty of SCC is suc­cess­ful­ly op­er­a­tional since last two years. All these years were very chal­leng­ing and wor­thy pe­ri­od from the point of view of gain­ing ex­pe­ri­ence and knowl­edge by solv­ing fab­ri­ca­tion and as­sem­bly prob­lems faced dur­ing con­struc­tion of 10 m tall cop­per made coax­i­al RF cav­i­ties and tack­ling RF re­lat­ed com­mis­sion­ing prob­lems. RF sys­tem op­er­ates with­in the fre­quen­cy range of 9 to 27 MHz for gen­er­at­ing max­i­mum 100 kV DEE volt­age. The con­struc­tion of the RF sys­tem de­mands mak­ing of nu­mer­ous crit­i­cal sol­der­ing and braz­ing joints in­clud­ing joints be­tween ce­ram­ic and cop­per along with main­tain­ing close di­men­sion­al ac­cu­ra­cies, as­sem­bly tol­er­ances, mir­ror sym­metric­i­ty, sur­face fin­ish and ut­most clean­li­ness. This paper pre­sents the de­tails of fab­ri­ca­tion and in­stal­la­tion pro­ce­dures and their ef­fects on the final per­for­mance of the cav­i­ties. It also high­lights the prob­lems faced dur­ing the com­mis­sion­ing pro­cess of the RF cav­i­ties.