Project of Cyclotron C250 for Proton Therapy Application // Proceedings of RuPAC 2010. <...> Computer modeling of the beam transmission efficiency dependent on the charge exchange with the residual gas for the CI-100 cyclotron // Proc. 6th International Computational Accelerator Physics Conference (ICAP). 2000. <...> Beam loss due to the charge exchange with the residual gas in the FLNR heavy ion cyclotrons // Proc. <...> Gough R. A., Mallory M. L. // IEEE Transactions on Nuclear Science. 1979. <...> Cyclotron vacuum model and H-gas stripping losses // Proc. of cyclotrons. 2010. <...> Shirkov G., Zschornack G. Electron Impact ion sources for Highly Charged ions (Vieweg and sohn Verlagsgesellschaft.), 1996. 16. <...> NIFS DATABASE (National Institute for Fusion Science), http://dbshino.nifs.ac.jp/ 20. <...> Beam losses due to the charge exchange with the residual gas in the cyclotron O. V. Karamyshev, G. A. Karamysheva, G. M. Skripka Joint Institute for Nuclear Research, 6 Joliot-Curie str., Dubna, Moscow region, 141980, Russia E-mail: gkaram@nu.jinr.ru This paper describes methods and results of simulation of light and heavy ion beams losses due to charge exchange with the residual gas in the cyclotron. <...> A code IONLOSS was created to simulate beam losses due to charge exchange with the residual gas while moving in the vacuum chamber. <...> Описана методика и представлены результаты расчетов потерь пучка тяжелых и лег ких ионов вследствие перезарядки на остаточном газе в камере циклотрона. <...> Была разра ботана программа IONLOSS, позволяющая рассчитывать потери пучков ионов при взаи модействии с молекулами остаточного газа в процессе движения пучка! <...>