Study of the performance of the FOOT experiment

Öz

In the last decade a continuous increase in the number of cancer patients treated with Particle Therapy (CPT) has been registered. CPT is still a discipline where the contribution coming from research in physics plays an important role. For example, different studies have shown that in proton therapy nuclear inelastic interactions of the incident beam with the patient tissues may lead to the fragmentation of the target nuclei producing a non negligible amount of target fragments, which may alter the estimated local dose deposition, especially in the entrance region. On the other hand, in heavy ion treatments, the main effect of nuclear inelastic interactions results in the break up of the incident ion instead of the target nuclei. The produced fragments have a longer range than the projectile, leading to an undesirable dose deposition beyond the Bragg peak. At present there is still a lack of complete and reliable experimental measurements of nuclear reaction cross sections for fragments produced in the interaction with tissues nuclei (H, C, Ca, O, N) of 60-250 MeV protons and 100-400 MeV/u carbon ions, which are the typical energies adopted in CPT treatments. These data will be important to develop a new generation of high quality treatment planning systems for CPT.

The FOOT (FragmentatiOn Of Target) experiment aims to fill the gap, performing a set of measurements of nuclear fragmentation cross sections relevant for CPT.  As far the study of target fragmentation is concerned, the FOOT experiment will adopt an inverse kinematic approach to overcome the difficulties related to the short fragments range (∼μm). In order to bypass the difficulties to manage a pure hydrogen target, it has been chosen a strategy of a double target separately made of C and C₂H₄ and the final cross section on Hydrogen will be obtained by subtraction. Further interest in this type of measurements comes from the issue of radioprotection in space missions, where the energy to be considered is higher and close to 1 GeV/u. FOOT consists of two different setups depending on the detection of heavy and light fragments: the heavy fragments are detected by a high precision tracking system in magnetic field, a time of flight measurement system and a calorimeter, while the lighter ones by a separated emulsion chamber. The optimization and the performance analysis of the setup have studied by means of the FLUKA^(1)(2)(3) Monte Carlo code and different detectors have been tested.

In this work, an overview of the FOOT experiment and a report on the study of the detector performances will be presented.

Anahtar Kelimeler

• hadrontherapy,cross section measurement,nuclear fragmentation,radioprotection

Kaynakça

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