Please use this identifier to cite or link to this item: http://hdl.handle.net/1942/33575
Title: Lineal energy calibration of a mini-TEPC via the proton-edge technique
Authors: BIANCHI, Anna 
Mazzucconi, D.
Selva, A.
Collautti, P.
Parisi, A.
Vanhavere, F.
RENIERS, Brigitte 
Conte, V.
Issue Date: 2021
Publisher: PERGAMON-ELSEVIER SCIENCE LTD
Source: RADIATION MEASUREMENTS, 141 (Art N° 106526)
Abstract: Purpose The possibility to calibrate microdosimetric spectra using the proton- and electron-edge was proposed many years ago. It consists of two steps: first identifying the edge and a marker point on it and then ascribing the correct lineal energy value to the position of the edge in the event size spectrum. The purpose of this work is to study rigorously the marker identification for the proton-edge in the mini-TEPC spectra measured in neutron and in clinical proton fields, and the correspondent lineal energy value to assign to it. Materials and methods Microdosimetric measurements were performed with a cylindrical miniaturized tissue-equivalent proportional-counter (mini-TEPC) in neutron and gamma rays radiation fields at the CN accelerator of the Legnaro National Laboratories of the Italian National Institute for Nuclear Physics (LNL-INFN) and in the clinical 62 MeV proton beam of the Southern National Laboratories of INFN (LNS-INFN). The fitting of the proton-edge region of the microdosimetric spectra with a Fermi-like function was studied in both neutron and proton fields to identify the most precise marker point. The lineal energy value to ascribe to it was determined starting from the maximum energy deposit in protons obtained in FLUKA simulations. Results Both in neutron radiation field and in clinical proton beams the flex and the intercept of the tangent through the inflection point are determined with similar precision. The flex was chosen as the most suitable marker of the proton-edge in sealed detectors because it is known to be less sensitive to pressure variations. The lineal energy value to ascribe to the flex position for 0.75 μm of propane depends on the irradiation geometry: 194 keV/μm for isotropic radiation fields and 165 keV/μm for mono-directional radiation fields orthogonal to the axis of the cylinder. The calibration values for the proton-edge have been converted in water by means of the mean stopping power ratio of water and propane for protons obtaining 171 keV/μm for isotropic radiation fields and 145 keV/μm for mono-directional radiation fields.
Keywords: Microdosimetry;Mini-TEPC;Calibration;Proton therapy
Document URI: http://hdl.handle.net/1942/33575
ISSN: 1350-4487
e-ISSN: 1879-0925
DOI: 10.1016/j.radmeas.2021.106526
ISI #: WOS:000624601100003
Rights: 2021 Elsevier Ltd. All rights reserved.
Category: A1
Type: Journal Contribution
Validations: ecoom 2022
Appears in Collections:Research publications

Files in This Item:
File Description SizeFormat 
1-s2.0-S135044872100010X-main.pdf
  Restricted Access
Published version4.15 MBAdobe PDFView/Open    Request a copy
2021 - Bianchi_Preproof.pdfPeer-reviewed author version1.04 MBAdobe PDFView/Open
Show full item record

WEB OF SCIENCETM
Citations

12
checked on Mar 22, 2024

Page view(s)

38
checked on Sep 5, 2022

Download(s)

4
checked on Sep 5, 2022

Google ScholarTM

Check

Altmetric


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.