Pixel‐detector System for Laser-accelerated Proton Beams
Dr. Sabine Reinhardt
Department of Medical Physics, Ludwig-Maximilians Univeristät München, Germany
Abstract: Laser-accelerated ion beams have very special properties because of the unique acceleration process. They are created in ultra-short bunches of high intensity with typically more than 109 particles/cm2/ns, making online characterization of these beams an ambitious task. As first step towards an online beam monitor for laser accelerated protons, a pixel detector based system has been integrated into a spectrometer as position-sensitive element in the dispersive spectrometer plane. The pixel detector system is based on a commercial detector, the RadEyeTM 1, a large area (2.5 x 5.0 cm²) CMOS image sensor. The sensor array is arranged in a matrix of 512 x 1024 pixels with 48 µm pixel pitch. In the present configuration up to 4 sensor modules can be read-out in parallel, thus allowing the coverage of a sensitive area as large as 50 cm2. The detector system has been thoroughly characterized at the Munich 14 MV Tandem accelerator in an 8-20 MeV proton beam in dc and pulsed irradiation mode, the latter simulating laser-accelerated like ns ion pulses. The detector system is able to resolve individual particles of the beam and saturates at a maximum pulse intensity of 107 protons/cm2 (20 MeV), showing a linear response over the whole dynamic range. Cross calibration with CR39 nuclear track detector and using laser-accelerated protons from the MPQ ATLAS laser, showed good agreement with the Tandem calibrations. A compact detector setup with integrated read-out electronics and on-board PC is now in routine use in laser-acceleration experiments. Ion spectra can be visualized in real-time on a shot-to-shot base, a major step with respect to beam monitoring in future applications of laser-accelerated ion beams. This work is carried out in the frame of the DFG funded cluster of excellence Munich Centre for Advanced Photonics (MAP).
Seminar takes place on Tuesday, June 2nd 2015 at 2:00 PM
in the IEAP meeting room, Praha 2 ‐ Albertov, Horská 3a/22.
| Ing. František Krejčí, Ph.D. tajemník semináře |
Ing. Stanislav Pospíšil, DrSc. ředitel |
Ing. Jan Žemlička předseda NPSS, ČS IEEE |
NUCLEAR & PLASMA SCIENCES SOCIETY CHAPTER
IEEE Czechoslovakia section
http://www.ieee.cz/en/nps