نتایج جستجو برای: diode dosimeter

تعداد نتایج: 23008  

Arass Rasaei, Raheleh Rooshenas

Introduction: Electronic portal imaging devices (EPIDs) could potentially be useful for intensity-modulated radiation therapy (IMRT) and VMAT QA. The data density, high resolution, large active area, and efficiency of the MV EPID make it an attractive option. However, EPIDs were designed as imaging devices, not dosimeters, and as a result they do not inherently measure dose in ...

2011
Timothy Olding Oliver Holmes Paul DeJean Kim B. McAuley Ken Nkongchu Giles Santyr L. John Schreiner

This paper explores the combination of cone beam optical computed tomography with an N-isopropylacrylamide (NIPAM)-based polymer gel dosimeter for three-dimensional dose imaging of small field deliveries. Initial investigations indicate that cone beam optical imaging of polymer gels is complicated by scattered stray light perturbation. This can lead to significant dosimetry failures in comparis...

2014
A Asena T Kairn S B Crowe S T Smith

This work examined the suitability of the PAGAT gel dosimeter for use in dose distribution measurements around high-density implants. An assessment of the gels reactivity with various metals was performed and no corrosive effects were observed. An artefact reduction technique was also investigated in order to minimise scattering of the laser light in the optical CT scans. The potential for atte...

Introduction Radiotherapy planning systems require many percentage depth dose (PDD) and profile measurements and there are various dosimeters that can be used to obtain these scans. As dose perturbation is particularly troublesome in smaller photon fields, using a low-perturbation, unshielded electron field diode (EFD) in these fields is of interest. The aim of this work was to investigate the ...

2015
Hyesu Jeon Wook Jae Yoo Sang Hun Shin Guwon Kwon Mingeon Kim Hyejin Kim Young Beom Song Kyoung Won Jang Won Sik Youn Bongsoo Lee

We developed a multichannel all-in-one phantom dosimeter system composed of nine sensing probes, a chest phantom, an image intensifier, and a complementary metal-oxide semiconductor (CMOS) image sensor to measure the dose distribution of an X-ray beam used in radiation diagnosis. Nine sensing probes of the phantom dosimeter were fabricated identically by connecting a plastic scintillating fiber...

2014
S. M. Gafar

In this study the spectrophotometric response of the Toluidine Blue O (TBO)-gelatin gel dosimeter irradiated with gamma rays was characterized. Preparation of dyed-gelatin gel takes place in neutral medium; to give eventually gel dosimeter has a sharp absorbance peak at 635 nm that bleaches quantitatively upon irradiation and the colour change can be measured with UV-VIS spectrophotometer. The ...

2017
Heather M Whitney Daniel F Gochberg C Waldenberg A Karlsson Hauer

The normoxic polymer gel dosimeter based on N-isopropyl acrylamide (NiPAM) is a promising full 3D-dosimeter with high spatial resolution and near tissue equivalency. NiPAM gel samples were irradiated to different doses using a linear accelerator. The absorbed dose was evaluated using MRI and statistical significance of the analysed data was calculated. The analysis was carried out using an in-h...

2002
W Czarnowski B Wielgomas J Krechniak

A passive dosimeter designed to measure exposure to hydrogen fluoride was tested under laboratory conditions over the concentration range of 0.56 – 4.47 mg HF/m. The lowest concentration was chosen to be close to the Polish TLV (0.5 mg HF/m). The dosimeter consists of a Whatman No.1 filter paper impregnated with K2HPO4 placed in a polyethylene holder protected by a polyethylene screen. After ex...

2002
David Banaszak

The Air Force sponsored flight tests using damage dosimeters, fabricated by The Boeing Company, to measure temperature and structural dynamic strains on B-52, F-15 and C-130 aircraft. The dosimeter measurements help diagnose difficultto-analyze structural conditions, such as acoustics and high cycle fatigue, and support the durability patch design process to repair secondary structure cracks. T...

2013
Ivan Buzurovic Timothy N. Showalter Matthew T. Studenski Robert B. Den Adam P. Dicker Junsheng Cao Ying Xiao Yan Yu Amy Harrison

In this article we describe commissioning and implementation procedures for the Dose Verification System (DVS) with permanently implanted in vivo wireless, telemetric radiation dosimeters for absolute dose measurements. The dosimeter uses a semiconductor device called a metal-oxide semiconductor field-effect transistor (MOSFET) to measure radiation dose. A MOSFET is a transistor that is general...

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