CALCULATION OF THE VACUUM SYSTEM OF THE MCC 30/15 CYCLOTRON

Yu. Menshovª

Federal State Unitary Enterprise Efremov Scientific Research Institute of Electrophysical Apparatus, Saint-Petersburg, Russia

Abstract

The concentration of molecules of residual gases has the big meaning in the process of acceleration the hydrogen's ions and deuterium's ions in cyclotron, as the intensive recharge of accelerated ions proceeds on these molecules. That is why the big attention was paid to the calculation of vacuum systems on the period of projecting the MCC-30/15 cyclotron. The MCC-30/15 cyclotron enabled to choose the optimal facilities of pumping speed and pumping location. The universal algorithm of calculation the vacuum systems has been developing in NIIEFA during the last few years. This algorithm is based on the method of electro- pneumatic analogies. It was adapted for identification the distribution of pressure the residual gases in vacuum chamber of multisector cyclotron. The algorithm was also realized in program application. The results of works with the developed program application are: the picture of sector's distribution of pressure the residual gases in median plane. On the ground of these results is easy to calculate the losses of accelerated beam on the whole of trajectory. The permissible level of the losses on the molecules of residual gases was accepted 7÷10% from the beam's input current for the MCC-30/15 cyclotron. After the results was clarified that the pumping with the help of two vacuum pumps provides such level of losses. These pumps should have the speed of 4500 l/s (hydrogen). The pumps are located oppositely to each other and attached to the peripheral circular cannel of vacuum chamber.

ª – corresponding author

Paper 

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