The FOOT (Fragmentation Of Target) Experiment

Abstract

Particle therapy uses protons or 12 C beams for the treatment of deep-seated solid tumors. Due to the features of the energy deposition of charged particles in matter, a limited amount of dose is released to the healthy tissue in the beam entrance region, while the maximum of the dose is released to the tumor at the end of the beam range, in the Bragg peak region. However nuclear interactions between beam and patient tissues induce fragmentation both of projectile and target. This has to be carefully taken into account since different ions have different effectiveness in producing a biological damage. In 12 C treatments the main concern are long range forward emitted secondary ions produced in projectile fragmentation that release dose in the healthy tissue after the tumor. Instead, in a proton treatment, the target fragmentation produces low energy, short range fragments along all the beam range. The FOOT experiment (FragmentatiOn Of Target) is designed to study these processes. Target nuclei ( 16 O, 12 C) fragmentation induced by 150-250 MeV proton beam will be studied by means of the inverse kinematic approach. 16 O, 12 C therapeutic beams, at the quoted kinetic energy per nucleon, collide on graphite and hydrocarbons target. The cross section on Hydrogen can be then extracted by subtraction. This configuration explores also the projectile fragmentation of these 16 O, 12 C beams, or other ions of therapeutic interest, such as 4 He for instance.The detector includes a magnetic spectrometer based on silicon pixel and strip detectors, a scintillating crystal calorimeter able to stop the heavier produced fragments, and a ∆E detector, with TOF capability, to achieve the needed energy resolution and particle identification. In addition to the electronic apparatus, an alternative setup based on the concept of the "Emulsion Cloud Chamber", coupled with the interaction region of the electronic FOOT setup, will provide the measurement of lighter charged fragments: protons, deuterons, tritons and Helium nuclei.

Dose build-up effects induced by delta electrons and target fragments in proton Bragg curves—measurements and simulations

“…However, the production rates (cross sections) of the target fragments and their energy spectra are still relatively unexplored. As the direct measurement of target fragments is extremely difficult the FOOT project (Fragmentation Of Target) plans to use a complex experimental setup and an inverse kinematic approach to investigate the target fragments (Battistoni et al 2017, Ambrosij et al 2017. In this work, a complementary approach was applied to examine the target fragment production: An indirect verification of the target fragment production was performed by investigating the extension and shape of the target fragment build-up region in a proton Bragg curve.…”

Carbon ions beam therapy monitoring with the INSIDE in-beam PET

“…The relevant aspects of FLUKA for particle therapy and treatment verification are thoroughly discussed in [31]. The agreement with experimental data is expected to improve thanks to the results of nuclear experiments dedicated to the measurement of nuclear fragmentation at energies relevant for hadrontherapy [32]. The simulation validation has been performed in previous works via the comparison with proton beam data acquired with a preliminary simple setup [13,24], with homogeneous phantoms irradiated with monoenergetic pencil beams [33] and clinical-like treatments [34], with PMMA phantoms including air cavities [18] and finally with in-vivo data measured during two consecutive proton irradiations of a patient [30].…”

“…The relevant aspects of FLUKA for particle therapy and treatment verification are thoroughly discussed in Battistoni et al (2016). The agreement with experimental data is expected to improve thanks to the results of nuclear experiments dedicated to the measurement of nuclear fragmentation at energies relevant for hadrontherapy (Battistoni et al 2017).…”

The Microstrip Silicon Detector (MSD) data acquisition system architecture for the FOOT experiment

“…Recently some experiments [3,4] have been dedicated to the study of beam fragmentation but the process of target fragmentation, which is the most relevant process in proton therapy, has not been investigated. To fill this gap, a new experiment FOOT (FragmentatiOn Of Target) has been proposed [5,6]. It will use the inverse kinematic approach [4] to measure the double differential cross-section of nuclear fragmentation, hence it is composed of different detectors capable of multiple measurements of the kinematic quantities of the charged fragments over a 10 • cone around the beam axis.…”