STATUS REPORT ON THE JAERI AVF CYCLOTRON SYSTEM

The AVF cyclotron system at JAERI Takasaki has been smoothly operated without serious troubles since the first beam extraction of 50 MeV 4He2+ in March 1991. A yearly operation time is about 3200 hours on an average for past several years. In the last three years, we performed some improvements and developments as follows: stabilization of the cyclotron beam, renewal of computers and basic programs for the control system, installation of a new ECR ion source and reconstruction of the rotary shutter. Furthermore, two series of M/Q=4 and M/Q=2 cocktail beams have been developed continuously. Now we are modifying the RF cavities for the flat-top acceleration by superimposing the fifth-harmonic frequency on the fundamental one.