| Title |
Micro Pattern Ionization Chamber with Adaptive Amplifiers as Dose Delivery Monitor for Therapeutic Proton LINAC |
| Authors |
- E. Cisbani, A. Carloni, S. Colilli, G. De Angelis, S. Frullani, F. Ghio, F. Giuliani, M. Gricia, M. Lucentini, C. Notaro, F. Santavenere, A. Spurio, G. Vacca
ISS, Rome, Italy
- A. Ampollini, P. Nenzipresenter, L. Picardi, C. Ronsivalle, M. Vadrucci
ENEA C.R. Frascati, Frascati (Roma), Italy
- E. Basile
Azienda Ospedaliera Papardo, Messina, Italy
- D.M. Castelluccio
ENEA-Bologna, Bologna, Italy
- C. Placido
University of Rome "La Sapienza", Rome, Italy
|
| Abstract |
A dedicated dose delivery monitor is under development for the TOP-IMPLART proton accelerator, the first LINAC for cancer therapy. It is expected to measure the intensity profile to precisely monitor the fully active 3+1D (x/y/z and intensity) dose delivery of each short pulses (few micro-s, 0.1-10 micro-A pulse current at ~100 Hz) of the therapeutic proton beam (up to 230 MeV). The monitor system consists of planar gas chambers operating in ionization regime with cathode plane made ofμpattern pads alternately connected by orthogonal strips*. The dedicated readout electronics features trans-impedance amplifier that dynamically adapts its integrating feedback capacitance to the incoming amount of charge, then opportunistically changing its gain. The measured absolute sensitivity is about 100 fC (better than 0.03 relative sensitivity), the dynamic range up to 10000 (2 gain settings) with time response at the level of few ns, and virtually no dead time. Small scale chamber prototype (0.875 mm pitch pads) and readout electronics have been tested and characterized under both electron (5 MeV) and proton (up to 27 MeV) beams.
|
| Footnotes & References |
* The pad-like design has been adopted to maximize the field uniformity, to reduce the chamber thickness and to obtain both x/y coordinates on a single chamber. |
| Funding |
Regione Lazio: TOP-IMPLART project |
| Paper |
download TUPG51.PDF [2.063 MB / 4 pages] |
| Poster |
download TUPG51_POSTER.PDF [3.468 MB] |
| Conference |
IBIC2016, Barcelona, Spain |
| Series |
International Beam Instrumentation Conference (5th) |
| Proceedings |
Link to full IBIC2016 Proccedings |
| Session |
Tuesday Poster Session |
| Date |
13-Sep-16 16:00–18:00 |
| Main Classification |
Charge Monitors and Other Instruments |
| Keywords |
proton, electronics, linac, cathode, factory |
| Publisher |
JACoW, Geneva, Switzerland |
| Editors |
Isidre Costa (ALBA-CELLS, Barcelona, Spain); Ubaldo Iriso (ALBA-CELLS, Barcelona, Spain); Francis Pérez (ALBA-CELLS, Barcelona, Spain); Volker RW Schaa (GSI, Darmstadt, Germany) |
| ISBN |
978-3-95450-177-9 |
| Published |
February 2017 |
| Copyright |
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