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Moreno-Pérez JA, Ruiz-García I, Martín-Holgado P, Romero-Maestre A, Anguiano M, Vila R, Carvajal MA. General Purpose Transistor Characterized as Dosimetry Sensor of Proton Beams. SENSORS (BASEL, SWITZERLAND) 2023; 23:3771. [PMID: 37050831 PMCID: PMC10098939 DOI: 10.3390/s23073771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 03/28/2023] [Accepted: 04/05/2023] [Indexed: 06/19/2023]
Abstract
A commercial pMOS transistor (MOSFET), 3N163 from Vishay (USA), has been characterized as a low-energy proton beam dosimeter. The top of the samples' housing has been removed to guarantee that protons reached the sensitive area, that is, the silicon die. Irradiations took place at the National Accelerator Centre (Seville, Spain). During irradiations, the transistors were biased to improve the sensitivity, and the silicon temperature was monitored activating the parasitic diode of the MOSFET. Bias voltages of 0, 1, 5, and 10 V were applied to four sets of three transistors, obtaining an averaged sensitivity that was linearly dependent on this voltage. In addition, the short-fading effect was studied, and the uncertainty of this effect was obtained. The bias voltage that provided an acceptable sensitivity, (11.4 ± 0.9) mV/Gy, minimizing the uncertainty due to the fading effect (-0.09 ± 0.11) Gy was 1 V for a total absorbed dose of 40 Gy. Therefore, this off-the-shelf electronic device presents promising characteristics as a dosimeter sensor for proton beams.
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Affiliation(s)
- J. A. Moreno-Pérez
- ECSens, Imuds, Department of Electronics and Computer Technology, ETSIIT, University of Granada, 18014 Granada, Spain; (J.A.M.-P.); (I.R.-G.)
| | - I. Ruiz-García
- ECSens, Imuds, Department of Electronics and Computer Technology, ETSIIT, University of Granada, 18014 Granada, Spain; (J.A.M.-P.); (I.R.-G.)
| | - P. Martín-Holgado
- National Accelerator Center (University of Sevilla, CSIC, JA), 41092 Sevilla, Spain; (P.M.-H.); (A.R.-M.)
| | - A. Romero-Maestre
- National Accelerator Center (University of Sevilla, CSIC, JA), 41092 Sevilla, Spain; (P.M.-H.); (A.R.-M.)
| | - M. Anguiano
- Department of Atomic, Molecular and Nuclear Physics, University of Granada, Institute for Biosanitary Research, Ibs. Granada, 18012 Granada, Spain;
| | - R. Vila
- National Fusion Laboratory, EURATOM-CIEMAT, 28040 Madrid, Spain;
| | - M. A. Carvajal
- ECSens, Imuds, Department of Electronics and Computer Technology, ETSIIT, University of Granada, 18014 Granada, Spain; (J.A.M.-P.); (I.R.-G.)
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Hsing CH, Oanh LDH, Chao TC, Lee CC, Hong JH, Cheng CC, Tseng CK, Tung CJ. MOSFET dose measurements for proton SOBP beam. Phys Med 2021; 81:185-190. [PMID: 33465755 DOI: 10.1016/j.ejmp.2020.12.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 12/06/2020] [Accepted: 12/07/2020] [Indexed: 12/15/2022] Open
Abstract
PURPOSE The aim of this work was to develop a computational scheme for the correction of the LET dependence on the MOSFET response in water phantom dose measurements for a spread-out Bragg peak (SOBP) proton beam. METHODS The LET dependence of MOSFET was attributed to the stopping power ratio of SiO2 to H2O and to the fractional hole yield in the SiO2 layer. Using literature values for the stopping powers of the continuous slowing down approximation and measured fractional hole yields vs. electric field and LET, formulas were derived for the computation of a dose-weighted correction factor of a SOBP beam. RESULTS Dose-weighted correction factors were computed for a clinical 190-MeV proton SOBP beam in a high-density polyethylene phantom. By applying correction factors to the SOBP beam, which consisted of weighted monoenergetic Bragg peaks, the MOSFET outputs were predicted and agreed well with the measured MOSFET responses. CONCLUSION By applying LET dependent correction factors to MOSFET data, quality assurance of dose verification based on MOSFET measurements becomes possible for proton therapy.
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Affiliation(s)
- Chun-Hui Hsing
- Medical Physics Research Center, Institute for Radiological Research, Chang Gung University and Chang Gung Memorial Hospital, Guishan Dist., Taoyuan City 333, Taiwan; Particle Physics and Beam Delivery Core Laboratory, Institute for Radiological Research, Chang Gung University/Chang Gung Memorial Hospital, Guishan, Taoyuan 333, Taiwan
| | - Luu Dang Hoang Oanh
- Department of Medical Imaging and Radiological Sciences, Chang Gung University, Guishan Dist., Taoyuan City 333, Taiwan
| | - Tsi-Chian Chao
- Medical Physics Research Center, Institute for Radiological Research, Chang Gung University and Chang Gung Memorial Hospital, Guishan Dist., Taoyuan City 333, Taiwan; Department of Medical Imaging and Radiological Sciences, Chang Gung University, Guishan Dist., Taoyuan City 333, Taiwan
| | - Chung-Chi Lee
- Medical Physics Research Center, Institute for Radiological Research, Chang Gung University and Chang Gung Memorial Hospital, Guishan Dist., Taoyuan City 333, Taiwan; Department of Medical Imaging and Radiological Sciences, Chang Gung University, Guishan Dist., Taoyuan City 333, Taiwan
| | - Ji-Hong Hong
- Department of Radiation Oncology, Chang Gung Memorial Hospital, Guishan, Taoyuan 333, Taiwan
| | - Chun-Chi Cheng
- National Space Organization, 8F, No.9, Prosperity 1st Rd., Hsinchu Science Park, Hsinchu 33378, Taiwan
| | - Chien-Kai Tseng
- National Space Organization, 8F, No.9, Prosperity 1st Rd., Hsinchu Science Park, Hsinchu 33378, Taiwan
| | - Chuan-Jong Tung
- Medical Physics Research Center, Institute for Radiological Research, Chang Gung University and Chang Gung Memorial Hospital, Guishan Dist., Taoyuan City 333, Taiwan; Department of Medical Imaging and Radiological Sciences, Chang Gung University, Guishan Dist., Taoyuan City 333, Taiwan.
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