Design and development of high power RF amplifier for 88 in. room temperature cyclotron at Variable Energy Cyclotron Centre (VECC), Kolkata

A tetrode based high power radio frequency (RF) amplifier has been designed, developed, and commissioned at Variable Energy Cyclotron Centre, Kolkata, India, for the 88-in. room temperature K130 cyclotron. The amplifier feeds power to a RF cavity based on the quarter-wave cantilever-type resonating structure to develop a high accelerating voltage for particle acceleration. The initial design of this amplifier was based on tetrode tube, which has already become obsolete. A new design of the RF amplifier has been made with a different tetrode of much lower power to satisfy the requirement of the cyclotron. This paper gives detailed insight into the various issues of the tetrode amplifier design and operational experience for the K130 cyclotron RF system.