introduction results of the experiment -...

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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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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

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-55

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-810

This work was supported by RFBR (project № 16-32-00393)* abahmutova@gmail.com