Calculation of the Effective Energy Release Centerʼs Position of Inorganic Scintillation Detectors for Calibration at Small “Source–Detector” Distances

Inorganic scintillation detectors are widely used to measure of dose rate in the environment due to their high sensitivity to photon radiation. A distinctive feature when using such detectors is the need to take into account of the position of the effective energy release center. This peculiarity is actual when using measuring instruments with inorganic scintillation detectors as working standards during calibration at short “source–detector” distances in conditions of low-background shield or using a facility with protection from external gamma radiation background in the dose rate range from 0.03 to 0.3 μSv/h (μGy/h). The purpose of this work was to calculate the position of the effective energy release center of NaI(Tl) scintillation detectors and to take it into account when working at short “source–detector” distances.An original method of determining the position of the effective energy release center when irradiating the side and end surfaces of inorganic scintillation detector with parallel gamma radiation flux and point gamma radiation sources at small “source–detector” distances using Monte Carlo methods is proposed. The results of calculations of the position of the effective energy release center of NaI(Tl) based detectors of “popular” sizes for the cases of parallel gamma radiation flux and point sources of gamma radiation at small “source–detector” distances are presented. The functional dependences of the position of the effective energy release center of NaI(Tl) based detectors on the distance to the point gamma radiation sources and the energy of gamma radiation sources are presented.As a result of the study it was found that for scintillation NaI(Tl) detectors of medium size (for example, Ø25×40 mm or Ø40×40 mm) the point gamma radiation source located at a distance of 1 m or more, creates a radiation field which does not differ in characteristics from the radiation field created by a parallel flux of gamma radiation. It is shown that approaching the point gamma radiation source to the surface of scintillation detector leads to displacement of the position of the effective energy release center to the surface of the detector.

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Calculation of the average dose rate for linear gamma-radiation sources

High Energy Chemistry ◽

10.1134/s0018143910060147 ◽

2010 ◽

Vol 44 (6) ◽

pp. 539-539 ◽

Cited By ~ 1

Author(s):

G. Z. Gochaliev

Keyword(s):

Gamma Radiation ◽

Dose Rate ◽

Average Dose ◽

Radiation Sources

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Application of CdZnTe Quasi-Hemispherical Detectors in Strong Gamma-Radiation Fields

EPJ Web of Conferences ◽

10.1051/epjconf/202022507004 ◽

2020 ◽

Vol 225 ◽

pp. 07004

Author(s):

Anatoli Loutchanski ◽

Viktors Fjodorovs ◽

Victor Ivanov ◽

Vadims Ogorodniks

Keyword(s):

Gamma Radiation ◽

Dose Rate ◽

Radiation Field ◽

Warm Up ◽

Radiation Fields ◽

Radiation Fluxes ◽

High Gamma ◽

Cdznte Detectors

The results of a study of some ways to improve spectroscopy characteristics of the CdZnTe quasi-hemispherical detectors when working in high gamma radiation fluxes are presented. It was shown that the use of IR illumination with a wavelength of 1050 nm or 1200 nm or at slight warm-up of the detector to +30°C … +40°C can significantly improve spectroscopy performance of the CdZnTe detectors of size 3.5 mm × 3.5 mm × 1.75 mm when operating in a tested gamma-radiation field with a dose rate up to 590 mGy/h.

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Влияние температуры окружающей среды на показания гамма-сцинтилляционного детектора

Вестник КРАУНЦ. Физико-математические науки ◽

10.26117/2079-6641-2021-34-1-203-211 ◽

2021 ◽

pp. 203-211

Author(s):

E. Yeboah ◽

S.V. Smirnov ◽

G.A. Yakovlev

Keyword(s):

Dose Rate ◽

Scintillation Detector ◽

Background Radiation ◽

Temperature Correction ◽

Experimental Result ◽

Correction Coefficient ◽

Scintillation Detectors ◽

Wide Range ◽

Different Temperatures ◽

Analytical Result

Scintillation detectors, which are widely used in environmental field study for measurement of radiation dose, are devices that experience wide range of temperature changes when in use. One of the characteristic of scintillation detectors are that, they are very sensitive to change in temperature and hence, every scintillation detector have temperature stabilization inside them. The temperature-dependence coefficient which is part of the detector calculation is the simplest stabilization method that is used. In this work, the BDKG-03 scintillation detector which is used to measure gamma radiation was operated under a controlled condition using a climatic chamber. The BDKG-03 scintillation detector has a temperature stabilizing built-in algorithm. The dose rate and count rate of the gamma background radiation for different temperatures ranging from -40 – +40 °C in increment of 10 °C were measured and studied. The main aim of this work was to study the effect of different ranges of temperature for subsequent calculation of temperature correction coefficient. An analytical result from the experimental result shows that dose rate measurement using the built-in algorithm gives a precise reading as temperature increases. The temperature correction coefficient was found based on dependence. Сцинтилляционные детекторы широко используются в исследованиях окружающей среды для измерения дозы облучения и представляют собой устройства, которые используются в широком диапазоне температур. Одной из характеристик сцинтилляционных детекторов является чувствительность к изменениям температуры, и, следовательно, каждый сцинтилляционный детектор имеет встроенный алгоритм температурной стабилизации. Коэффициент температурной зависимости, который является частью автоматических расчетов детектора, представляет собой простейший метод стабилизации. В данной работе сцинтилляционный детектор БДКГ-03, используемый для измерения гамма-излучения, работал в контролируемых условиях с использованием климатической камеры. Сцинтилляционный детектор БДКГ-03 имеет встроенный заводской алгоритм стабилизации температуры. Были измерены и исследованы мощность дозы и скорость счета фонового гамма-излучения для различных температур от -40 до +40 °C с шагом в 10 °C. Основной целью данной работы было изучение влияния различных диапазонов температур для последующего расчета температурного поправочного коэффициента. Результат эксперимента показывает, что измерение мощности дозы с использованием встроенного алгоритма дает более точные показания в верхнем диапазоне рабочих температур.

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Влияние зданий на суммарный гамма-фон

Вестник КРАУНЦ. Физико-математические науки ◽

10.26117/2079-6641-2021-35-2-100-109 ◽

2021 ◽

pp. 100-109

Author(s):

E. Yeboah ◽

P. Macdonald ◽

G. Yakovlev

Keyword(s):

Gamma Radiation ◽

Dose Rate ◽

Scintillation Detector ◽

Background Radiation ◽

Equivalent Dose ◽

Horizontal Distance ◽

Global Level ◽

New Approach ◽

Equivalent Dose Rate ◽

Gamma Background

The influence of buildings on the total gamma background radiation was investigated. The total gamma radiation between a building made from bricks and a field, which are 100 m apart (away from the influence of other buildings), was measured using a scintillation detector. Measurements of ambient equivalent dose rate at different heights above the soil and a horizontal distance from 0.1 m – 100 m in variable steps were taken. A new approach was developed to assess the contribution of gamma background radiation from the soil and the building to the total gamma background radiation. It was obtained that the gamma background radiation contributed by buildings, greatly affects the total gamma background radiation up to a distance of 2 m, at which there was a significant decrease in the total gamma background radiation. The percentage of the building that contributes to the total gamma background radiation is noted to be between 4 – 29% of the total gamma background. This shows that most of the background radiation in the environment is contributed by the gamma background radiation in the soil. Also, the annual equivalent dose received by a person who sits near the building was 0.09 mSv, which was higher than an adult who works far away from the building (0.08 mSv). Both were however less than the global level. It also was found that the best place to install a detector for measuring gamma radiation was found to be a distance of 1.5 m away from the building. Исследовано влияние зданий на общий гамма-фон. Гамма-фон между кирпичным зданием и полем, находящимся на расстоянии 100 м друг от друга (вдали от влияния других зданий), измерялось с помощью сцинтилляционного детектора. Были проведены измерения мощности амбиентного эквивалента дозы на разной высоте над почвой и на горизонтальном расстоянии от 0,1 м до 100 м с переменным шагом от здания. Был разработан новый подход для оценки вклада от почвы и здания в общий гамма-фон. Было получено, что гамма-излучение, вносимое зданиями, сильно влияет на суммарный гамма-фон на расстоянии до 2 м, на котором наблюдалось значительное уменьшение излучения в общем. Отмечено, что процент вносимого зданием вклада в общий гамма-фон, составляет от 4 до 29%. Это показывает, что большая часть фонового излучения в окружающей среде обеспечивается гамма-излучением почвы. Кроме того, годовая эквивалентная доза, полученная человеком, сидящим рядом со зданием, составила 0,09 мЗв, что выше, чем у взрослого, работающего далеко от здания (0,08 мЗв). Однако оба значения ниже среднемирового. Также было обнаружено, что лучшим местом для установки детектора гамма-излучения будет удаленное на 1,5 м от здания.

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Comparison of Lead, Copper and Aluminium as Gamma Radiation Shielding Material through Experimental Measurements and Simulation Using MCNP Version 4c

International Journal of Contemporary Research and Review ◽

10.15520/ijcrr/2018/9/08/584 ◽

2018 ◽

Vol 9 (08) ◽

pp. 20193-20206 ◽

Cited By ~ 1

Author(s):

Md. Akhlak Bin Aziz ◽

Md. Faisal Rahman ◽

Md. Mahidul Haque Prodhan

Keyword(s):

Gamma Radiation ◽

Sodium Iodide ◽

Experimental Approach ◽

Radiation Shielding ◽

Test Material ◽

Simulation Techniques ◽

Radiation Sources ◽

Simulation Monte Carlo ◽

Shielding Material ◽

Code Version

The paper compares Lead, Copper and Aluminium as gamma radiation shielding material using both experimental and simulation techniques. Cs- 137 (662KeV), Na-22 (511KeV) and Na- 22(1274KeV) were used as gamma radiation sources and a sodium iodide (NaI) detector was used to detect the radiation. Variations were noted for detected gamma count rates by changing shielding material thickness. In the experimental approach, thickness was varied by placing sheets of a particular test material one by one. For simulation, Monte Carlo n- Particle (MCNP) code version 4c was used and the geometry of the whole experimental setup was plotted in it. The results were then compared for each test material and it was found that lead is the best shielding material for gamma radiation followed by copper and aluminium.

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