scholarly journals Calibration of the Absolute Efficiency of Well-Type NaI(Tl) Scintillation Detector in 0.121–1.408 MeV Energy Range

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Dalal Al Oraini
Keyword(s):  
Energy Range ◽  
Sodium Iodide ◽  
Detection Efficiency ◽  
Solid Angle ◽  
Radioactive Isotopes ◽  
Activity Measurements ◽  
Absolute Efficiency ◽  
Sodium Iodide Detector ◽  
The Absolute ◽  
Detector Material

Well-type NaI(Tl) detectors are beneficial for low-level photon activity measurements because of the near 4π solid angle that can be gained with them. The detection efficiency can differ with the source-to-detector system geometries, the absorption of the photon in the detector material, and attenuation layers in front of the detector face. For these purposes, the absolute efficiency and the coincidence corrections of the well-type sodium iodide detector have been measured at 0.121–1.408 MeV energy range (obtained from 152Eu, 137Cs, and 60Co radioactive isotopes). The covenant between the experimental (present work) and the published theoretical values is good, with the high discrepancies being less than 1%.

The absolute detection efficiency of an NE213 liquid scintillator for neutrons in the energy range 50–450 MeV

1982 ◽  
Vol 192 (2-3) ◽  
pp. 407-413 ◽  
Author(s):  
S. Cierjacks ◽  
M.T. Swinhoe ◽  
M.T. Swinhoe ◽  
L. Buth ◽  
S.D. Howe ◽  
...  
Keyword(s):  
Energy Range ◽  
Detection Efficiency ◽  
Liquid Scintillator ◽  
The Absolute

scholarly journals Limitations in the assessment of radon dose: the role of activity measurements in the human body

2019 ◽  
Vol 24 ◽  
pp. 92
Author(s):  
J. Kalef-Ezra ◽  
S. Valakis
Keyword(s):  
Effective Dose ◽  
Human Body ◽  
Detection Efficiency ◽  
Medical Physics ◽  
High Sensitivity ◽  
Temporal Variations ◽  
Cold Season ◽  
Whole Body ◽  
Group I ◽  
Activity Measurements

Radon-222 is classified in the Group I of the human carcinogens. The in situ decay of inhaled 222Rn and its short-lived decay products (T1/2 <30 min) is the main source of radiation burden to the general population of natural origin. The corresponding effective dose is routinely calculated as the product of the 222Rn concentration in air, a predetermined dosimetric constant and a factor that depends on the space type (e.g. residential or public building, cave, mine, etc). However, in practice, there are large spatial and temporal variations in the activity ratio of each progeny to 222Rn in air, the characteristics of the progeny carrying particles and the metabolism of each progeny depending on air quality, as well as differences in the anatomic and physiological characteristics between individuals, that vary substantially even with time. Therefore, the currently employed dosimetric approach may introduce large uncertainties. In the hypothetical case of acute deposition and full retention in the human body of equal activities of all 222Rn progeny, about 93% of the effective dose is due to the decaying 214Po. The 214Po activity can be assessed by measurement of its γ-emitting precursor, 214Bi, which is in full equilibrium with 214Po in the human body. The 214Bi activity can be measured using a high-sensitivity whole-body counter with high counting uniformity, such as the one in use at the Ioannina University Medical Physics Department. Its detection efficiency and its dependence on body shape and size were assessed by Monte Carlo simulations. Measurements carried out in healthy adult volunteers residing at a short distance from the counter, indicated a mean total body 214Bi activity (TBBi) of ~100 Bq during the cold season of the year and lower during the hot one. Higher mean TBBi levels were found in male than in female adults. Therefore, TBBi measurements may allow for accurate radon-related risk assessment on individual base.

THE REACTION OF UNSATURATED CARBOHYDRATES WITH CARBON MONOXIDE AND HYDROGEN: V. ABSOLUTE STEREOCHEMISTRY OF ANHYDRODEOXYHEPTITOLS FROM 3,4,6-TRI-O-ACETYL-D-GLUCAL. STEREOCHEMISTRY OF HYDROFORMYLATION. CONFORMATIONAL ANALYSIS

1965 ◽  
Vol 43 (5) ◽  
pp. 1375-1381 ◽  
Author(s):  
Alex Rosenthal ◽  
Hans J. Koch
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Carbon Monoxide ◽  
Absolute Configuration ◽  
Sodium Iodide ◽  
Crystallographic Analysis ◽  
X Ray ◽  
Dicobalt Octacarbonyl ◽  
The Absolute ◽  
Compound Ii ◽  
Absolute Stereochemistry

3,4,6-Tri-O-acetyl-D-glucal reacted with carbon monoxide and hydrogen in the presence of dicobalt octacarbonyl to yield a mixture of two epimeric anhydrodeoxyheptitols, namely, 4,5,7-tri-O-acetyl-2,6-anhydro-3-deoxy-D-manno-heptitol (I) and 4,5,7-tri-O-acetyl-2,6-anhydro-3-deoxy-D-gluco-heptitol (II). De-O-acetylation of the mixture, followed by chromatographic separation, yielded crystalline 2,6-anhydro-3-deoxy-D-manno-heptitol (III) and 2,6-anhydro-3-deoxy-D-gluco-heptitol (IV). Reaction of the mixture of heptitols (I) and (II) with p-bromobenzenesulfonyl chloride, followed by fractional crystallization of the brosylates, gave pure 4,5,7-tri-O-acetyl-2,6-anhydro-1-O-(p-bromophenylsulfonyl)-3-deoxy-D-gluco-heptitol (VII). The absolute configuration of (VII) has been previously established by X-ray crystallographic analysis. The absolute configuration of (III) was established by correlation with that of (VII). The conversion of compound (II) into various derivatives is described.Reaction of 3,4,6-tri-O-acetyl-D-glucal with carbon monoxide and deuterium afforded 2,6-anhydro-3-deoxy-D-manno-heptitol-1,1,3-2H3 (XIII) and 2,6-anhydro-3-deoxy-D-gluco-heptitol-1,1,3-2H3 (XIV). Examination of the nuclear magnetic resonance (n.m.r.) spectra of the normal and deuterated anhydrodeoxyheptitols confirmed the structural assignments and showed that cis addition to the double bond took place to give (XIV).Comparison of the exchange reaction of sodium iodide with 4,5,7-tri-O-acetyl-2,6-anhydro-3-deoxy-1-O-tosyl-D-gluco-heptitol (VIII) and with 4,5,7-tri-O-acetyl-2,6-anhydro-3-deoxy-1-O-tosyl-D-manno-heptitol (XV) revealed that the equatorial primary tosyloxy group of (VIII) was exchanged by iodine twice as readily as the axial primary tosyloxy group of (XV).

Study of a single line of sight gamma ray diagnostics for measurements of the absolute gamma ray emission from JET

2021 ◽  
Vol 16 (12) ◽  
pp. C12019
Author(s):  
G. Marcer ◽  
M. Nocente ◽  
L. Giacomelli ◽  
G. Gorini ◽  
E. Perelli Cippo ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Neutron Emission ◽  
Fusion Reaction ◽  
Branching Ratio ◽  
Plasma Source ◽  
Line Of Sight ◽  
Extended Plasma ◽  
Absolute Efficiency ◽  
The Absolute ◽  
Gamma Ray Emission

Abstract The fusion power produced in a DT thermonuclear reactor is currently determined by measuring the absolute 14 MeV neutron yield of the D(T, α)n fusion reaction. Measurements of 17 MeV gamma rays born from the much less probable D(T, 5He)γ reaction (branching ratio of ∼10−5) have been proposed as an alternative independent method to validate the neutron counting method and also to fulfill the requests of the nuclear regulator for licensing ITER DT operations. However, the development of absolute 17 MeV gamma ray emission measurements entails a number of requirements, such as: (i) knowledge of the 17 MeV gamma ray to 14 MeV neutron emission branching ratio; (ii) the simulation of the gamma ray transport from the extended plasma source to the gamma ray detectors; (iii) a careful determination of the absolute efficiency of previously calibrated gamma ray spectrometers. In this work, we have studied the possibility to infer the global gamma ray emission rate from measurements made with a 3″ × 6″ LaBr3 spectrometer installed at the end of a collimated tangential line of sight at the JET tokamak and using the neutron emission from deuterium plasmas of the most recent experimental campaigns. Results show that 17 MeV gamma ray fluxes at the end of this tangential line of sight have a weak dependence (less than 5%) on the plasma profile and can therefore be used to infer the total emission from the plasma.

Experimental studies of the absolute total delayed neutron yields from neutron induced fission of 238U in the energy range 1–5 MEV

2002 ◽  
Vol 41 (1-4) ◽  
pp. 135-144 ◽  
Author(s):  
V.M. Piksaikin ◽  
L.E. Kazakov ◽  
V.A. Roshchenko ◽  
S.G. Isaev ◽  
G.G. Korolev ◽  
...  
Keyword(s):  
Energy Range ◽  
Experimental Studies ◽  
Delayed Neutron ◽  
Induced Fission ◽  
The Absolute

scholarly journals Scanning Transmission X-Ray Microscopy in the Soft Energy Range with Very Large Solid Angle of Detection for X-ray Fluorescence Imaging

2018 ◽  
Vol 24 (S2) ◽  
pp. 86-87
Author(s):  
L. Luhl ◽  
K. Andrianov ◽  
A. Haidl ◽  
H. Dierks ◽  
A. Dehlinger ◽  
...  
Keyword(s):  
Energy Range ◽  
Fluorescence Imaging ◽  
Solid Angle ◽  
X Ray ◽  
Scanning Transmission

Lung Cancer Detection Using a Miniature Sodium Iodide Detector and Cobalt-57 Bleomycin

CHEST Journal ◽  
1984 ◽  
Vol 85 (1) ◽  
pp. 84-88 ◽  
Author(s):  
James M. Woolfenden ◽  
William S. Nevin ◽  
H. Bradford Barber ◽  
Douglas J. Donahue
Keyword(s):  
Lung Cancer ◽  
Cancer Detection ◽  
Sodium Iodide ◽  
Sodium Iodide Detector ◽  
Lung Cancer Detection
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