NEUTRON DOSE ASSESSMENT USING SAMPLES OF HUMAN BLOOD AND HAIR

2019 ◽  
Vol 186 (2-3) ◽  
pp. 202-205
Author(s):  
Daniela Ekendahl ◽  
Peter Rubovič ◽  
Pavel Žlebčík ◽  
Ivan Hupka ◽  
Ondřej Huml ◽  
...  
Keyword(s):  
Human Blood ◽  
Unique Feature ◽  
Gamma Ray ◽  
Neutron Dose ◽  
Dose Assessment ◽  
Gamma Ray Spectrometry ◽  
Nuclear Accidents ◽  
Body Tissues ◽  
Neutron Exposure ◽  
Practical Feasibility

Abstract The unique feature of nuclear accidents with neutron exposure is the induced radioactivity in body tissues. For dosimetry purposes, the most important stable isotopes occurring in human body, which can be activated by neutrons, are 23 Na and 32 S. The respective activation reactions are as follows:23Na(n,γ)24Na and32S(n,p)32P. While sodium occurs in human blood, sulfur is present in human hair. In order to verify the practical feasibility of this dosimetry technique in conditions of our laboratory, samples of human blood and hair were irradiated in a channel of a training reactor VR-1.24Na activity was measured by gamma-ray spectrometry.32P activity in hair was measured by means of a proportional counter. Based on neutron-spectrum calculation, relationships between neutron dose and induced activity were derived for both blood and hair.

scholarly journals Application of a new in situ calibration technique for gamma spectrometry and comparison of in situ and laboratory measurements

2021 ◽  
Vol 72 (1) ◽  
pp. 29-35
Author(s):  
Davor Rašeta ◽  
Branko Petrinec ◽  
Dinko Babić ◽  
Marko Šoštarić
Keyword(s):  
Gamma Spectrometry ◽  
Gamma Ray ◽  
Gamma Ray Spectrometry ◽  
Nuclear Accidents ◽  
Laboratory Measurements ◽  
Calibration Technique ◽  
In Situ Calibration ◽  
Hpge Detectors ◽  
Complicated Process

Abstract In situ gamma ray spectrometry was developed to quickly measure large areas of land following nuclear accidents. However, a proper calibration of detectors for in situ measurements is a long and complicated process. One tool designed to make this calibration quick is the InSiCal software. We compared 5,000 s in situ measurements with two different HPGe detectors calibrated using the InSiCal software and laboratory measurements of samples collected at the same locations. Our findings suggest that in situ gamma spectrometry using InSiCal software can provide reasonably accurate data, but some improvements are needed.

scholarly journals Additional dose assessment from the activation of high-energy linear accelerators used in radiation therapy

2008 ◽  
Vol 23 (2) ◽  
pp. 58-64 ◽  
Author(s):  
Embarka Ateia ◽  
Olivera Ciraj-Bjelac ◽  
Milojko Kovacevic ◽  
Petar Belicev ◽  
Bratislav Cvetkovic ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Dose Rate ◽  
Linear Accelerator ◽  
Gamma Ray ◽  
High Energy ◽  
Dose Assessment ◽  
Whole Body ◽  
Gamma Ray Spectrometry ◽  
Additional Dose ◽  
Linear Accelerators

It is well known that medical linear accelerators generate activation products when operated above certain electron (photon) energies. The aim of the present work is to assess the activation behavior of a medium-energy radiotherapy linear accelerator by applying in situ gamma-ray spectrometry and dose measurements, and to estimate the additional dose to radiotherapy staff on the basis of these results. Spectral analysis was performed parallel to dose rate measurements in the isocenter of the linear accelerator, immediately after the termination of irradiation. The following radioisotopes were detected by spectral analysis: 28Al, 62Cu, 56Mn, 64Cu, 187W, and 57Ni. The short-lived isotopes such as 28Al and 62Cu are the most important factors of the clinical routine, while the contribution to the radiation dose of medium-lived isotopes such as 56Mn, 57Ni, 64Cu, and 187W increases during the working day. Measured dose rates at the isocenter ranged from 2.2 ?Sv/h to 10 ?Sv/h in various measuring points of interest for the members of the radiotherapy staff. Within the period of 10 minutes, the dose rate decreased to values of 0.8 ?Sv/h. According to actual workloads in radiotherapy departments, a realistic exposure scenario was set, resulting in a maximal additional annual whole body dose to the radiotherapy staff of about 3.5 mSv.

Gamma-Ray Spectrometric Analysis of Some Trace Elements in the Human Articular Disc of the Mandible

1963 ◽  
Vol 03 (02) ◽  
pp. 175-182 ◽  
Author(s):  
Bo Bergman ◽  
Rune Söremark
Keyword(s):  
Trace Elements ◽  
Neutron Activation ◽  
Quantitative Data ◽  
Thermal Neutron Flux ◽  
Gamma Ray ◽  
Dry Weight ◽  
Gamma Ray Spectrometry ◽  
Spectrometric Analysis ◽  
Articular Disc ◽  
Group Separation

SummaryBy means of neutron activation and gamma-ray spectrometry the concentrations in the human mandibular articular disc of the following elements have been determined: Na, Mn, Cu, Zn, Rb, Sr, Cd, W, and Au. The discs were obtained at necropsy from seven men and nine women, ranging in age from 56 to 71 years.The activation was carried out in a thermal neutron flux of about 1.7 XlO12 neutrons × cm−2 × sec.−1 for about 20 hours. A chemical group separationwas performed before the gamma-ray spectrometry. Quantitative data based on the dry weight of the cartilage samples were obtained by comparing the photo-peak area of the identified elements with those of appropriate standards.

Neutron dose evaluation of Elekta Linac at two energies (10 & 18 MV) by MCNP code and comparison with experimental measurements

2014 ◽  
Vol 6 (1) ◽  
pp. 1006-1015
Author(s):  
Negin Shagholi ◽  
Hassan Ali ◽  
Mahdi Sadeghi ◽  
Arjang Shahvar ◽  
Hoda Darestani ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Measurement Data ◽  
Calculated Data ◽  
High Energy ◽  
Neutron Dose ◽  
Dose Assessment ◽  
Photon Flux ◽  
Dose Equivalent ◽  
Monte Carlo Techniques ◽  
Neutron Dose Equivalent

Medical linear accelerators, besides the clinically high energy electron and photon beams, produce other secondary particles such as neutrons which escalate the delivered dose. In this study the neutron dose at 10 and 18MV Elekta linac was obtained by using TLD600 and TLD700 as well as Monte Carlo simulation. For neutron dose assessment in 2020 cm2 field, TLDs were calibrated at first. Gamma calibration was performed with 10 and 18 MV linac and neutron calibration was done with 241Am-Be neutron source. For simulation, MCNPX code was used then calculated neutron dose equivalent was compared with measurement data. Neutron dose equivalent at 18 MV was measured by using TLDs on the phantom surface and depths of 1, 2, 3.3, 4, 5 and 6 cm. Neutron dose at depths of less than 3.3cm was zero and maximized at the depth of 4 cm (44.39 mSvGy-1), whereas calculation resulted  in the maximum of 2.32 mSvGy-1 at the same depth. Neutron dose at 10 MV was measured by using TLDs on the phantom surface and depths of 1, 2, 2.5, 3.3, 4 and 5 cm. No photoneutron dose was observed at depths of less than 3.3cm and the maximum was at 4cm equal to 5.44mSvGy-1, however, the calculated data showed the maximum of 0.077mSvGy-1 at the same depth. The comparison between measured photo neutron dose and calculated data along the beam axis in different depths, shows that the measurement data were much more than the calculated data, so it seems that TLD600 and TLD700 pairs are not suitable dosimeters for neutron dosimetry in linac central axis due to high photon flux, whereas MCNPX Monte Carlo techniques still remain a valuable tool for photonuclear dose studies.

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