An analytical investigation of time-dependant discharge on electrostatic deflector at nirs-930 cyclotron

A phenomenon of a time-dependant discharge on an electrostatic deflector has been investigated in NIRS AVF-930 cyclotron. The discharge occurs as a function of time interval of a few to around fifteen minutes, which is in inverse proportion to an arc power of ion source and applying voltage on the deflector electrode, even if the normal accelerated beam is intercepted at central region. It has been supposed to be induced by a certain kind of irrelevant ions having very low-energy, act as an initiator for the discharge. In this paper the details of the discharge phenomenon and some results of the investigation are presented.