The Joint Accelerator Conferences Website (JACoW) is an international collaboration that publishes the proceedings of accelerator conferences held around the world.
TY - CONF AU - Psoroulas, S. AU - Bula, C. AU - Fernandez Carmona, P. AU - Klimpki, G. AU - Meer, D. AU - Weber, D.C. ED - Chrin, Jan ED - Schaa, Volker RW TI - Challenges in Fast Beam Current Control Inside the Cyclotron for Fast Beam Delivery in Proton Therapy J2 - Proc. of Cyclotrons2016, Zurich, Switzerland, September 11-16, 2016 C1 - Zurich, Switzerland T2 - International Conference on Cyclotrons and Their Applications T3 - 21 LA - english AB - The COMET cyclotron* at PSI has been successfully used to treat patients with static tumors using the spot scanning technique, i.e. sequentially irradiating different positions inside the tumor volume. Irradiation time for each position ranges from micro- to milliseconds, with total treatment duration of about a minute. For some tumors (e.g. lung) physiological motion (e.g. respiration) interferes with the scanning motion of the beam, lowering treatment quality**. For such mobile tumors, we are developing a new technique called continuous line scanning (CLS), aiming at reducing treatment time by more than 50%. In CLS, dose rate should stabilize (within few percent) within tenths of a millisecond. We thus implemented a first prototype for fast, real-time beam control: a PID controller sets the internal electrostatic vertical deflector of the accelerator, regulating the beam current output based on the instantaneous current measured just before the patient and the knowledge of the transmission from the accelerator to the patient. In pre-clinical experiments, we achieved good control of the global dose delivered; open issues will be tackled in the next version of the controller. PB - JACoW CP - Geneva, Switzerland SP - 126 EP - 129 KW - proton KW - cyclotron KW - controls KW - power-supply KW - target DA - 2017/01 PY - 2017 SN - 978-3-95450-167-0 DO - 10.18429/JACoW-Cyclotrons2016-TUA02 UR - http://jacow.org/cyclotrons2016/papers/tua02.pdf ER -