WP3 - Microdosimetry

WP3 - Microdosimetry

Leader: S. Agosteo

The aim of WG3 is to measure microdosimetric spectra across the proton Bragg peak with detectors with tissue-equivalent (TE) walls/converters unloaded and loaded with boron and fluorine. The microdosimetric spectra will be assessed at the same depths where cells will be irradiated by WG4, thus providing a physical characterization of the radiation field at cellular dimensions. Proton irradiations will be performed at LNS and TIFPA. Already available microdosimeters will be employed, namely tissue-equivalent proportional counters (TEPCs) and silicon telescopes. The feasibility of employing SiC devices for microdosimetry will also be studied for their better tissue-equivalence and radiation hardness. Moreover, experimental spectra at the nanometric level will be assessed for providing data for modelling (WG1).

Miniature dual-TEPC systems were constructed at LNL for BNCT applications, allow- ing microdosimetry measurements with excellent spatial resolution in high beam intensity while a dual-TEPC with walls loaded with 11B will be constructed.

The silicon microdosimeter is based on the monolithic telescope technology. The standard structure consists of a ∆E stage and an E residual-energy stage about 2 μm and 500 μm in thickness, respectively. The ∆E stage acts as a solid state microdosimeter, while the E stage gives information on the energy and the type of the impinging particle. It should be mentioned that these telescope devices also allow to discriminate the type of the impinging particle through a scatter-plot. The contribution of each particle to the microdosimetric distribution can be hence assessed. The silicon detectors will be coupled to boron-loaded (or F loaded) and pure TE plastics. Coupling with a pure boron/fluorine target is also foreseen for maximizing the production of alpha particles from the studied reactions. It should be mentioned that these telescope devices also allow to discriminate the type of the impinging particle through a scatter-plot. The contribution of each particle to the microdosimetric distribution can be hence assessed. The silicon detectors will be coupled to boron-loaded (or F loaded) and pure TE plastics. Coupling with a pure boron/fluorine target is also foreseen for maximizing the production of alpha particles from the studied reactions.

Link to the First Annual Activity Report

Papers:

▪ G. Petringa et al. “Radiobiological quantities in proton-therapy: estimation and validation using Geant4-based Monte Carlo simulations”, Physica Medica 58, P72-80, 2019

V. Conte et al.,“Microdosimetry at the catana 62 mev proton beam with a sealed miniaturized tepc.”,Physica Medica, Vol.64, 114-122, (2019)
A. Selva et al., “Towards the use of nanodosimetry to predict cell survival”, Radiation protection and dosimetry, 183-1-2 (2019)
D. Mazzucconi et al., “Micorodosimetry at nanometric scale with an avalanche-confinement TEPC: Responce against a helium ion beam”, Radiation Protection Dosimetry 183-1-2 (2019)
M. Rebai et al, “New thick silicon carbide detectors: Response to 14 MeV neutrons and comparison with single-crystal diamonds”, NIM A 946 (2019)
S. Tudisco et al., “Silicon carbide for future intense luminosity nuclear physics investigations”, Nuovo Cimento C (2019)
C. Ciampi et al., “Nuclear fragment identification with Delta E-E telescopes exploiting silicon carbide detectors”, NIMA 925 (2019)
D. Mazzucconi et al. “Nano-microdosimetric investigation at the proton irradiation line of CATANA”, Radiation Measurements 123, 26-33 (2019)

Conferences:

▪ MCMA 2019 conference, Montreal, Canada, Giugno 2019 http://iccr-mcma.org/

▫ Talk: “MIRTO: A microdosimetric study and RBE measurement with 62 MeV clinical proton beam”

Poster:

▪ 59th Annual conference of Particle Therapy Co Operative Group , (Manchester), 10-15 Giugno 2019 - https://ptcog58.org

▫ E-poster: “Microdosimetric study and RBE measurement at CATANA protontherapy facility for the treatment of ocular melanoma”