The development of a novel array detector for overcoming the dosimetry challenges of measuring in very short pulsed charged particle beams: the Elidose project

In-beam dose measurements are paramount for any application seeking to harness the effects of the radiation beam, so all the future applications of the laser accelerated beams (as generated in the ELI and CETAL projects) will need such measurements. With a very long history in measuring doses in charged particle beams, the medical and industrial applications setup a number of methods that could be also used for the dosimetry of the beams generated by laser pulses. Dose measurements rely heavily on what is seen as the gold standard in dose measurement: the ion chambers. Ion chambers have both limitations and advantages, and in our case the disadvantage could be the large number of corrections to be applied in order to calculate a correct dose from the measured charge. The ELIDOSE project tries to address these problems by proposing an array detector that would allow the simultaneous measurement of the recombination and polarity corrections, and of the dose. The detector consists of four identical ion chambers mounted together in a PMMA frame and the project will analyze its response to various charged particle beams and the reciprocal influences of the chambers on each other. These reciprocal influences of the four chambers are studied through the FLUKA modeling of the detector and, in order to hone the simulations of the detectors, we initially compared the results of the measurements performed with an Advanced Markus^TM chamber in the proton beam delivered at the 3-MV Tandetron^TM from IFIN-HH. The paper presents the results of these initial measurements and how these results will be used to modify the simulation parameters. (authors)