Search results for "sperimentale"

Determinazione della componente fotonica all’interno della colonna termica del reattore TRIGA mediante letture ESR di dosimetri di alanina

2014

Phenol compounds for Electron Spin Resonance dosimetry of gamma and neutron beams

2014

OPTICAL SENSING OF POLLUTANTS BY FLUORESCENT CARBON NANODOTS

2022

Charge loss correction in CZT pixel detectors at low and high fluxes: analysis of positive and negative pulses

2018

Charge losses are typical drawbacks in cadmium–zinc–telluride (CZT) pixel detectors. The effects of these phenomena are strongly related to the interaction point of the photons and are more severe for photon interactions at the inter-pixel gap and near the pixelated anode. In this work, we present some original techniques able to correct charge losses in pixelated CZT detectors at both low and high fluxes. The height, the shape and the arrival time of collected- and induced-charge pulses with both positive and negative polarities are analysed to recover charge losses after the application of charge sharing addition (CSA). Sub-millimetre CZT pixel detectors, fabricated by different manufactu…

Synthesis of luminescent glass monoliths embedding water-soluble Carbon dots

2014

Carbon dots (CD) are an emerging class of nanomaterials, currently motivating an intense scientific interest because of their bright and characteristically tunable fluorescence, and their possible applications such as sensors, lasers, imaging agents, white light emitting devices [1]. While most studies focused on CDs in liquid phase, a strong effort is being recently devoted to produce fluorescent solids embedding highly dispersed CDs. Many of these procedures are elaborate and require pre-functionalization of the dots [2]. Here we report a novel and very facile route to prepare glass monoliths containing CDs with no need of pre-functionalization of the dots. Our low-cost synthesis method p…

Analisi dei vetri di orologi tramite risonanza paramagnetica elettronica (EPR) e termoluminescenza (TL) per dosimetria retrospettiva

2016

Negli ultimi anni è cresciuto il rischio di esposizioni radiologiche non controllate della popolazione, sia a causa di incidenti associati ad applicazioni industriali e mediche delle radiazioni ionizzanti sia in seguito ad incidenti legati all’abbandono o alla dismissione di sorgenti ma anche ad un uso criminale di materiale radioattivo [1–3]. Gli effetti biologici prodotti dalle radiazioni ionizzanti dipendono fortemente dalla quantità di energia impartita per unità di massa (dose assorbita) [4]. Pertanto, nell’ambito di un incidente radiologico, disporre di procedure di ricostruzione della dose assorbita da un individuo può contribuire oltre che ad identificare i membri della popolazione …

Sviluppo e Applicazioni di nuovi materiali per la dosimetria delle radiazioni ionizzanti

The Research Activities carried out during the Three-year International PhD Course in Applied Physics of the candidate Salvatore Gallo had two main topics related to dosimetry of ionizing radiations (IR): the analysis of 3D gel dosimeters and the analysis of solid state dosimeters through electron spin resonance. Both these activities are focused on a careful study of new materials for the IR Dosimetry, both in terms of physical characterization of these new materials and of the optimization of readout methods for dosimetric measurements. The study performed through various techniques such as UV-Vis absorption spectroscopy, NMR Relaxometry, Magnetic Resonance Imaging (MRI) and Electron Spin…

Defects in graphenic materials by EPR and DFT methods

2016

We have used EPR to characterize a series of defects, which are characterized by tipical g-tensors, linewidths, intensity as function of the temperature. Mostly, signals arises from the presence of conduction electrons, and of so-called "edge states", that are unpaired electrons located at the edges of graphenic flakes; the relative molecular orbitals are not very muche extended as for low-lying orbitals, and are located within few atomic rows from edges with zig-zag topology. All the relative EPR signals are naturally and intrinsically generated by all graphitic materials. We now extend our study to the defects that are formed inside the graphenic structure. There is a full zoo of possible…

Characterization of phenolic pellets for ESR dosimetry in photon beam radiotherapy.

2017

We report a study of the dosimetric features of phenolic compounds for applications in radiation therapy dosimetry of clinical photon beams by using ESR spectroscopy. After the optimization of the ESR readout parameters, basic dosimetric properties (such as intra-batch reproducibility, dose-response, sensitivity, linearity, dose rate dependence, tissue-equivalence and signal stability) of laboratory-made phenolic dosimeters in form of pellets were investigated. Furthermore, these dosimeters were tested for measuring the depth dose profile of a 6 MV clinical photon beam. The results reported show that these dosimeters are promising materials for ESR dosimetric applications in radiation thera…

New materials for ESR dosimetry in clinical photon and electron beams: Phenol Compounds.

2016

In the last decades several research laboratories have shown an increasing interest aimed at extending the applicability of ESR-dosimetry to radiotherapy with different types of radiation beams. ESR is a spectroscopic method for investigating the structure and dynamics of such paramagnetic species. The concentration of radiation-induced free radicals is proportional to the energy released inside in the medium. Our research group has started an investigation of the ESR response of some phenols compounds for possible ESR dosimetric applications suitable features, such as high efficiency of radiation-matter energy transfer and radical stability at room temperature. In particular, the phenoloct…