The Joint Accelerator Conferences Website (JACoW) is an international collaboration that publishes the proceedings of accelerator conferences held around the world.
TY - CONF AU - Caldara, M. AU - Bosser, J. AU - Calvi, G.M.A. AU - Lanzavecchia, L. AU - Parravicini, A. AU - Rojatti, E. AU - Viviani, C. ED - Henderson, Stuart ED - Akers, Evelyn ED - Satogata, Todd ED - Schaa, Volker R.W. TI - Online Spill Intensity Monitoring for Improving Extraction Quality at CNAO J2 - Proc. of IPAC2015, Richmond, VA, USA, May 3-8, 2015 C1 - Richmond, VA, USA T2 - International Particle Accelerator Conference T3 - 6 LA - english AB - The CNAO Foundation is the first Italian center for deep hadrontherapy with Protons and Carbon Ions, performing treatments since September 2011. The extracted beam energy and intensity can vary over a wide range (60-250 MeV for Protons and 120-400 MeV/u for Carbon Ions, 4e6/10¹⁰ pps); the beam intensity uniformity during the slow extraction process is a fundamental requirement for achieving accurate and fast treatments. CNAO developed an online Fast Intensity Monitor (FIM), not perturbing the extracted beam, capable of measuring beam intensity with a bandwidth of 50kHz and a resolution of 1%. It consists of a thin (0.8 μm) metallic foil that emits secondary electrons when traversed by the beam. The electrons are multiplied by a Channeltron device, polarized at high voltage versus ground. The Channeltron output current is amplified and converted in a Pulse Width Modulated (PWM) signal, which is then decoupled and transmitted to the equipment room, where an FPGA implements a servo-spill. The work presents the detector, the floating electronics, the preliminary measurements with beam and the integration in a closed loop on the synchrotron air-core quadrupole obtaining promising results. PB - JACoW CP - Geneva, Switzerland SP - 907 EP - 909 KW - electron KW - proton KW - ion KW - electronics KW - extraction DA - 2015/06 PY - 2015 SN - 978-3-95450-168-7 DO - 10.18429/JACoW-IPAC2015-MOPHA050 UR - http://jacow.org/ipac2015/papers/mopha050.pdf ER -