THE VARIAN 250 MeV SUPERCONDUCTING COMPACT PROTON CYCLOTRON: MEDICAL OPERATION OF THE 2nd MACHINE,PRODUCTION AND COMMISSIONING STATUS OF MACHINES

Abstract

Varian Medical Systems Particle Therapy has successfully commissioned its 2nd superconducting compact proton cyclotron for use in proton therapy in 2008. The 250 MeV machine serves as proton source for treatments at the first clinical proton therapy center in Germany which opened in early 2009. Furthermore, Varian is currently commissioning and factory testing its 3rd machine. We report on the operation and performance of the 2nd machine as well as on the successful cool-down, quench testing, and magnetic shimming of the 3rd machine. In addition we present RF commissioning plans using a newly developed solid state amplifier, and plans for the upcoming factory beam commissioning in the new Varian cyclotron scanning nozzle test cell, scheduled for October 2010. Finally we provide a brief status and outlook on machines no. 4 to 7.IMP;Chinese Academy of Science