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6MV photons
Development of the beam diagnostic system for the radiobiological research at the proton linear accelerator I-2
A. Bakhmutova*, N. Markov, A. Kantsyrev, A. Golubev Institute for Theoretical and Experimental Physics NRC "Kurchatov Institute", Moscow, Russia
Introduction
Experimental setup
At the present time at ITEP there is a possibility to investigate the biological mechanisms of the low energy protons on living systems on linear accelerator I-2. The unique high current linear accelerator allows to obtain 20 MeV intense proton beams. They could be used for the radiobiological research in a wide range of absorbed doses and for different cell types. Currently some preliminary experiments were made to specify diagnostic equipment required for further investigations. This work presents the main results on the proton beam parameters measurements such as beam current, beam cross section dimension as well as the measurements of the absorbed dose and depth dose distribution using different types of detectors.
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Time, mks
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Signal from FCT
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t1 t2
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Signal from FCT
Energy max., MeV 22.5
Pulse width., mks 2 - 30
Field size max., mm 85
Particles (per pulse), 1/cm2 107 - 1011
Range in water, mm ~ 5
LET min., keV/mkm 2.4
Parameters of proton linear accelerator I-2 in context of the radiobiological research
- Set of collimators with inner diameter from 85 to 12 mm;- Fast current transformer FCT-082 (Bergoz) for particles
measurements;- CCD camera SDU-415 and a set of scintillators (plastic and
Al2O3);- Various type of detectors for dose, particle fluency, energy
loss measurements (radiochromic films, CR-39, diamond detector, calorimeter).
Main equipment used in experiments
Vacuum pipe
Collimator
CCD camera
Fact current transformer
Scintillator
Detectors (RCF, CR-39, diamond, etc.)
Maylar mirror
p, 22.5 MeV
Results of the experimentFluence measurements
Radiochromic films (RCF) dosimetry
A - integral valueq -elementary chargez - particles chargeK - amplifier coeff.SB - FCT sensitivity
W/o collimator
Collimator 12 mm
48-h after irradiation
Before
After
Beam uniformity
Dose distr.Irradiated film
netOD distr.
Depth-dose measurements with RCF
MD
-55
-2
HD
-810
This work was supported by RFBR (project № 16-32-00393)* [email protected]