• T.S. Dixit, S.T. Chavan, R. Krishnan, C.S. Nainwad, S.N. Pethe, K.A. Thakur, T. Tiwari, M.M. Vidwans
  SAMEER, Mumbai
• A. Deshpande
  Sokendai, Ibaraki

A successful development of a 6 MeV electron radiotherapy machine at SAMEER, India was reported earlier*. Now a 15 MeV electron linac prototype is designed, developed and tested at our site. We have measured a beam current of 80 mA at the X-ray target attached to the linac. Energy gained by electrons in a cavity chain of about 1.2 m length is measured to be more than 15 MeV using a 6 MW klystron power source. An RF window capable of handling 12kW average power is attached to the linac tube and it is cooled by water. The final linac parameters measured were at par with the designed values. A high voltage modulator and control console for the linac are designed and developed in house. This paper will describe key aspects of the design and development process of the complete system. Also future applications are planned like-dual energy dual mode linac for radiotherapy, cargo scanning system and compact compton X-ray source using this technology is briefed in this paper.

* R.Krishnan et. al. "S band linac tube developmental work in SAMEER", FR5REP083, PAC09, Vancouver, Canada.

• T. Iwashita, T. Adachi, T. Arai, Y. Arakida, M. Hasimoto, H. Someya, K. Takayama, M. Wake
  KEK, Ibaraki
• T.S. Dixit
  SAMEER, Mumbai
• K. Mochiki, T. Sano
  Tokyo City University, Tokyo

The KEK-DA (Digital Accelerator) is a modification of the KEK 500 MeV booster*, in which an induction acceleration system is employed. It has an ability to accelerate arbitrary ions with their possible charge states**. An outline of the acceleration scenario is described and a necessary control system fully integrating the induction acceleration system is given in details. The KEK-DA is a rapid cycle synchrotron operating at 10 Hz; the accelerating pulse voltage must be dynamically varied in time to follow the ramping magnetic field. A novel technique combining the pulse density control and intermittent operation of acceleration cells is required. The intelligent gate control system which uses 1 GHz digital signal processors (DSPs) has been designed. Construction of the KEK-DA is in the final stage; installation of the induction cells and the power supplies are done. The whole system including gate control system is demonstrated with high voltage outputs,long-term stability of the system through a heat run is examined. Also a future plan which replaces DSPs by FPGA (Field Programmable Gate Array)is discussed.

* K.Takayama et al., JOURNAL OF APPLIED PHYSICS 101, 063304 (2007).
** K.Takayama et al., "KEK Digital Accelerator for Material and Biological Sciences" in this conference.