Read by QxMD icon Read

Radiation Protection Dosimetry

A L M C Malthez, E M Yoshimura, V L S N Button, M B Freitas
We propose a personal dosemeter based on the combination of thermoluminescence (TL) and optically stimulated luminescence (OSL) detectors employing the advantages of both techniques. The new OSL/TL dosemeter using a badge manufactured in a 3D printer was tested for assessment of photon doses in simulated and actual situations of exposure. Additionally, Brazilian national performance tests adapted to the new dosemeter were run as well as the performance tests of international standards on the passive dosimetry systems...
April 19, 2018: Radiation Protection Dosimetry
M Romero-Expósito, S Viñals, O Ortega-Gelabert, B Fernández, P Jiménez-Bonilla, J Praena, C Domingo
The proton beam produced in the Nuclear Physics line of the tandem accelerator of the Centro Nacional de Aceleradores was used to generate a neutron field. In particular, 1.912 MeV protons were used to produce well-known epithermal neutrons through the p+7Li → n+7Be reaction. The aim of the work was to characterize this field while testing the performance of a Bonner sphere spectrometer in the epithermal range. Measurements were performed in four locations at different angle (0°, 30°, 60° and 90°) from beam incidence direction in order to study the angular dependence of the field...
April 13, 2018: Radiation Protection Dosimetry
S Chiriotti, A Parisi, F Vanhavere, M De Saint-Hubert, C Vandevoorde, J Slabbert, P Beukes, E de Kock, J Symons
Measurements of the dose equivalent at different distances from the isocenter of the proton therapy center at iThemba LABS were previously performed with a tissue-equivalent proportional counter (TEPC). These measurements showed that the scattered radiation levels were one or two orders of magnitude higher in comparison to other passive scattering delivery systems. In order to reduce these radiation levels, additional shielding was installed shortly after the measurements were done. Therefore, the aim of this work is to quantify and assess the reduction of the secondary doses delivered in the proton therapy room at iThemba LABS after the installation of the additional shielding...
April 13, 2018: Radiation Protection Dosimetry
Everton R Silva, Bruno M Freitas, Denison S Santos, Cláudia L P Maurício
Occupational neutron fields usually have energies from the thermal range to some MeV and the characterization of the spectra is essential for estimation of the radioprotection quantities. Thus, the spectrum must be unfolded based on a limited number of measurements. This study implemented an algorithm based on the bee colonies behavior, named Artificial Bee Colony (ABC), where the intelligent behavior of the bees in search of food is reproduced to perform the unfolding of neutron spectra. The experimental measurements used Bonner spheres and 6LiI (Eu) detector, with irradiations using a thermal neutron flux and three reference fields: 241Am-Be, 252Cf and 252Cf (D2O)...
April 13, 2018: Radiation Protection Dosimetry
José T Álvarez-Romero, Mario R Cabrera Vertti, Stefan Gutiérrez Lore, José Antonio G Tamayo, Gonzalo Walwyn Salas, Daniel de la Cruz Hernández
The results of the comparison between SSDL-ININ and SSDL-CPHR (pilot laboratory) demonstrates the competence of the SSDL-ININ for the performance of the KR in 192Ir. The RININ/CHPR ratio for the calibration coefficients is 0.989 ± 0.005. The comparison uses three SI-HDR 1000-Plus as transfer chambers, series: A02423, A941755 and A973052. CPHR used a secondary standard PTW 3304 chamber, s/n 154, calibrated at PTB and ININ employed a secondary standard SI-90008 s/n A963391, calibrated at NPL. To determine KR, the SSDL-CPHR used the IAEA TEC-DOC-1274 and the SSDL-ININ used the IPEM (UK) code of practice...
April 9, 2018: Radiation Protection Dosimetry
Sunil K Singh, M S Kulkarni
Measurement of dose due to low and medium energy X-ray using an ionization chamber needs special considerations as the wall thickness of the detector plays an important role in signal generation. A thin and plane wall ionization chamber having 900 cc volume was developed to study its calibration coefficient with air kerma (Kair) rate and ambient dose equivalent (H*(10)) rate at various X-ray beam qualities generated from a dosimetry grade X-ray machine. Optimized ionization chamber wall thickness was determined through measurements where a flat energy response of the ionization chamber could be established...
April 5, 2018: Radiation Protection Dosimetry
Adnan Lahham, Hussein ALMasri
A total of 120 adult female and male patients randomly selected from 10 hospitals in the West Bank and Gaza Strip were investigated for organ and effective doses from abdominal computed tomography scan. The organs considered in this study are liver, stomach and colon. Assessment of radiation doses was performed by using a commercially available Monte Carlo based software VirtualDose™ CT, a product of Virtual Phantoms, Inc. The software utilizes male and female tissue equivalent mathematical phantoms of all ages and sizes from new born up to morbidly obese patients...
April 5, 2018: Radiation Protection Dosimetry
S Domanski, P Tulik, B Boimski
The calibration laboratory revises periodically the dosimetric properties of its calibration fields. For reference neutron fields based on radionuclide sources, it is due to presence of isotopic impurities in the source ingredients. Consequently, in long term, the admixtures and their decay products become significant. Neglecting the impact of such effect leads to inconsistencies between the neutron emission rate observed during the measurements and the emission rate derived from the decay curve of the main isotope...
April 5, 2018: Radiation Protection Dosimetry
H Cui, K Tang
The profile of the residual signals of LiF:Mg,Cu,P within the region of dosimetric interest was approximated by a cubic curve. The conventional analysis, the GCA developed in CIEMAT and the GCA developed in this laboratory were compared. For GCA developed in this laboratory, the 5 μGy test dose could be well measured even after measurement at 10 mGy and obviously at lower doses. The 20 μGy test dose could be well measured even after measurement at 50 mGy. The residual signals caused by previous irradiations in the case of using only reader anneal can be more effectively eliminated by GCA developed in this laboratory than GCA developed in CIEMAT...
March 28, 2018: Radiation Protection Dosimetry
Michalis Mazonakis, Stefanos Kachris, John Damilakis
This study provided second cancer risk estimates from radiation therapy for common solid tumors presented in reproductive-aged females. Three-dimensional treatment plans were generated for 10 patients with cervical, uterine, rectal, lung or breast carcinomas. The organ equivalent dose (OED) and the lifetime attributable risk (LAR) for carcinogenesis to organs receiving high doses were estimated for all study participants with a mechanistic model. This model accounts for cell-killing, tissue repair and dose fractionation effects...
March 28, 2018: Radiation Protection Dosimetry
Jun Lin, Meng Lu, Tong Wu, Lei Yang, Tongning Wu
In the electric vehicles (EVs), children can sit on a safety seat installed in the rear seats. Owing to their smaller physical dimensions, their heads, generally, are closer to the underfloor electrical systems where the magnetic field (MF) exposure is the greatest. In this study, the magnetic flux density (B) was measured in the rear seats of 10 different EVs, for different driving sessions. We used the measurement results from different heights corresponding to the locations of the heads of an adult and an infant to calculate the induced electric field (E-field) strength using anatomical human models...
March 23, 2018: Radiation Protection Dosimetry
B Pérez López, J F Navarro, M A López
Iodine-131 is one of the main concerns from the point of view of radiological protection in a short term after a nuclear accident. The WBC Laboratory of CIEMAT has developed a methodology for in vivo monitoring of radioiodine in the thyroid of exposed individuals in case of emergency. Thyroid-neck phantoms of different sizes are required for calibrating the detection systems in appropriate counting geometries for the measurement of exposed population. A Low-Energy Germanium (LEGe) detector and a Fastscan Counter were calibrated using a set of thyroid phantoms fabricated by CIEMAT...
March 23, 2018: Radiation Protection Dosimetry
Edilaine H Silva, Lara Struelens, Peter Covens, Satoshi Ueno, Yasuhiro Koguchi, Filip Vanhavere, Nico Buls
Hospital based workers that perform interventional radiology are at risk of reaching the eye lens dose limit of 20 mSv/y. These workers are exposed to the radiation scattered by the patient, which creates a complex field, with low radiation energy reaching the eyes of the medical staff from wide angles. Therefore, the dosemeter used in the assessment of the eye lens dose of interventional radiologists needs to respond accurately in such conditions. In this study, the angular response of a commercially available radiophotoluminescent glass dosemeter, GD-352M, was optimized via Monte Carlo simulations, aiming at its use as eye lens dosemeter in interventional radiology...
March 23, 2018: Radiation Protection Dosimetry
Ali Tarighatnia, Asghar Mesbahi, Amir Hossein Mohammad Alian, Evin Koleini, Nader Nader
The objective of this study was to evaluate radiation exposure levels in conjunction with operator dose implemented, patient vascular characteristics, and other technical angiographic parameters. In total, 756 radial coronary angioplasties were evaluated in a major metropolitan general hospital in Tabriz, Iran. The classification of coronary lesions was based on the ACC/AHA system. One interventional cardiologist performed all of the procedures using a single angiography unit. The mean kerma-area product and mean cumulative dose for all cases was 5081 μGy m2 and 814...
March 23, 2018: Radiation Protection Dosimetry
P M Raste, B K Sahoo, J J Gaware, Anil Sharma, M R Waikar, A A Shaikh, R G Sonkawade
Researchers have already established that inhalation of high radon concentration is hazardous to human health. Radon concentration has been measured in water and soil, in various part of Kolhapur district has been carried out by the AQTEK Smart RnDuo which is an active device technique. The observed minimum value of the radon mass exhalation rate of the soil is 13.16 ± 0.83 mBq/kg/h and maximum is 35.11 ± 1.84 mBq/kg/h. The minimum value of the Radon concentration in water is 0.33 ± 0.052 Bq/L and maximum is 7...
March 19, 2018: Radiation Protection Dosimetry
P Deatanyah, E K K Abavare, A Menyeh, J K Amoako
This paper describes an effort to respond to the suggestion in World Health Organization (WHO) research agenda to better quantify potential exposure levels from a range of radiofrequency (RF) sources at 200 public access locations in Ghana. Wide-band measurements were performed-with a spectrum analyser and a log-periodic antenna using three-point spatial averaging method. The overall results represented a maximum of 0.19% of the ICNIRP reference levels for public exposure. These results were generally lower than found in some previous but were 58% (2...
March 16, 2018: Radiation Protection Dosimetry
Hollie Harmer, Sally Radford, Mary Smail
Patients undergoing dual energy X-ray absorption (DEXA) scans are exposed to small doses of ionizing radiation. Few papers have been published on the effective dose and organ dose for patients undergoing such scans on newer DEXA scanners. PCXMC 2.0 was used to calculate adult patient dose arising from DEXA scans. PCXMC 2.0 calculations were compared to published data and a discrepancy was noted for organ dose. Following this, effective and organ dose were measured on an anthropomorphic phantom using TLDs as a second comparison...
March 16, 2018: Radiation Protection Dosimetry
K O Inozemtsev, V V Kushin, A Strádi, I Ambrožová, S Kodaira, J Szabó, R V Tolochek, V A Shurshakov
The evaluation of different components of secondary radiation (charged fragments and neutrons) onboard ISS is described. Solid-state nuclear track detectors CR-39™ were applied for the measurements of short-range nuclear fragments, while the measurements of neutrons were carried out by means of thermo-luminescent dosimeters with various concentrations of 6Li and 7Li. The flux of charged secondaries and the gamma-equivalent neutron dose are presented in function of the low-LET dose in various modules of the Russian segment of ISS...
March 16, 2018: Radiation Protection Dosimetry
Jongtae Jeong, Nak Yul Ko, Dong-Keun Cho, Min Hoon Baik, Ki-Hoon Yoon
Naturally occurring radioactive materials (NORM) wastes with different radiological characteristics are generated in several industries. The appropriate options for NORM waste management including disposal options should be discussed and established based on the act and regulation guidelines. Several studies calculated the exposure dose and mass of NORM waste to be disposed in landfill site by considering the activity concentration level and exposure dose. In 2012, the Korean government promulgated an act on the safety control of NORM around living environments to protect human health and the environment...
March 16, 2018: Radiation Protection Dosimetry
G Benito, J C Sáez, J B Blázquez, J Quiñones
The most interesting events in Radiological Monitoring Network correspond to higher values of H*(10). The higher doses cause skewness in the probability density function (PDF) of the records, which there are not Gaussian anymore. Within this work the probability of having a dose >2 standard deviations is proposed as surveillance of higher doses. Such probability is estimated by using the Hermite polynomials for reconstructing the PDF. The result is that the probability is ~6 ± 1%, much >2.5% corresponding to Gaussian PDFs, which may be of interest in the design of alarm level for higher doses...
March 15, 2018: Radiation Protection Dosimetry
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"