Measurement of the directional correlation of the 1038–605 keV gamma cascade in 134Ba

1969 ◽  
Vol 47 (24) ◽  
pp. 2873-2877 ◽  
Author(s):  
H. W. Taylor ◽  
B. Singh ◽  
A. H. Kukoč ◽  
J. D. King
Keyword(s):  
Gamma Ray ◽  
Detection System ◽  
Correlation Coefficients ◽  
Coincidence System ◽  
Probable Spin ◽  
Spin Sequence

The directional correlation of the 1038–605 keV gamma-ray cascade in 134Ba has been determined using the well-known 1365–605 keV gamma-ray cascade as a reference. The detection system was a conventional fast–slow coincidence system using a 9 cm3 cylindrical Ge(Li) counter and a 5 cm × 5 cm NaI(Tl) counter. The observed correlation coefficients were A2 = 0.285 ± 0.030, A4 = −0.002 ± 0.050. The most probable spin sequence for the 1038–605 cascade is 3 (1, 2) 2 (2) 0 with a quadrupole content of 35–49% for the 1038-keV transition.

PO-1728: Development of a new prompt gamma ray detection system for full 3D proton range verification

2020 ◽  
Vol 152 ◽  
pp. S957-S958
Author(s):  
P. Costanza ◽  
R.I. Mackay ◽  
K.J. Kirkby ◽  
M.J. Taylor
Keyword(s):  
Gamma Ray ◽  
Detection System ◽  
Prompt Gamma ◽  
Range Verification

scholarly journals Progress in radionuclide characterisation in marine sediments using an underwater gamma-ray spectrometer in 2π geometry

2019 ◽  
Vol 21 ◽  
pp. 29
Author(s):  
E. G. Androulakaki ◽  
C. Tsabaris ◽  
M. Kokkoris ◽  
G. Eleftheriou ◽  
D. L. Patiris ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Detection System ◽  
Full Energy Peak ◽  
Gamma Ray Spectrometry ◽  
Peak Efficiency ◽  
Full Energy ◽  
Effective Manner ◽  
Energy Peak ◽  
Full Energy Peak Efficiency

The in-situ gamma-ray spectrometry is a well suited method for seabed mapping applications, since it provides rapid results in a cost effective manner. Moreover, the in-situ method is preferable to the commonly applied laboratory measurements, due to its beneficial characteristics. Therefore, the development of in-situ systems for seabed measurements continuously grows. However, an efficiency calibration of the detection system is necessary for obtaining quantitative results in the full spectral range. In the present work, an approach for calculating the full-energy peak efficiency of an underwater insitu spectrometer for measure- ments on the seabed is presented. The experimental work was performed at the coastal site of Vasilikos (Cyprus). The experimental full-energy peak efficiency of the in-situ was determined in the energy range 1400–2600 keV, by combining the in-situ and laboratory reference measurements. The experimental effi- ciency results were theoretically reproduced by means of Monte Carlo (MC) simulations, using the MCNP5 code.

scholarly journals Computer-Aided System Application Value for Assessing Hip Development

2020 ◽  
Vol 11 ◽  
Author(s):  
Yaoxian Jiang ◽  
Guangyao Yang ◽  
Yuan Liang ◽  
Qin Shi ◽  
Boqi Cui ◽  
...  
Keyword(s):  
Hip Joint ◽  
Detection System ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Diagnostic Efficiency ◽  
X Rays ◽  
Computer Aided Detection ◽  
Sharp Angle ◽  
Center Edge ◽  
Computer Aided

PurposeA computer-aided system was used to semiautomatically measure Tönnis angle, Sharp angle, and center-edge (CE) angle using contours of the hip bones to establish an auxiliary measurement model for developmental screening or diagnosis of hip joint disorders.MethodsWe retrospectively analyzed bilateral hip x-rays for 124 patients (41 men and 83 women aged 20–70 years) who presented at the Affiliated Zhongshan Hospital of Dalian University in 2017 and 2018. All images were imported into a computer-aided detection system. After manually outlining hip bone contours, Tönnis angle, Sharp angle, and CE angle marker lines were automatically extracted, and the angles were measured and recorded. An imaging physician also manually measured all angles and recorded hip development, and Pearson correlation coefficients were used to compare computer-aided system measurements with imaging physician measurements. Accuracy for different angles was calculated, and the area under the receiver operating characteristic (AUROC) curve was used to represent the diagnostic efficiency of the computer-aided system.ResultsFor Tönnis angle, Sharp angle, and CE angle, correlation coefficients were 0.902, 0.887, and 0.902, respectively; the accuracies of the computer-aided detection system were 89.1, 93.1, and 82.3%; and the AUROC curve values were 0.940, 0.956, and 0.948.ConclusionThe measurements of Tönnis angle, Sharp angle, and CE angle using the semiautomatic system were highly correlated with the measurements of the imaging physician and can be used to assess hip joint development with high accuracy and diagnostic efficiency.

scholarly journals Design and Optimisation of a Three Layers Thermal Neutron, Fast Neutron and Gamma-Ray Imaging System

2020 ◽  
Vol 225 ◽  
pp. 07002
Author(s):  
H. Al Hamrashdi ◽  
S. D. Monk ◽  
D. Cheneler
Keyword(s):  
Spatial Resolution ◽  
Gamma Ray ◽  
Imaging System ◽  
Detection System ◽  
Fast Neutrons ◽  
Silicon Photomultiplier ◽  
Current Configuration ◽  
Lithium Glass ◽  
Gamma Ray Imaging ◽  
Small Form Factor

The design and configuration of a multi-layered imaging system with the ability to detect thermal neutrons, fast neutrons and gamma rays has been developed and its efficacy demonstrated. The work presented here numerically determines the systems efficiency and spatial resolution, using 252Cf and 137Cs as a case study. The novelty of this detection system lies in the use of small form factor detectors in a three-layer design, which utilises neutron elastic scattering and Compton scattering simultaneously. The current configuration consists of 10 mm thick natural lithium glass (GS10) scintillator integrated with a 20 mm thick plastic scintillator (EJ-204) in the first layer, a 15 mm thick lithium glass (GS10) scintillator in the second and a 30 mm thick CsI(Tl) scintillator forming the final layer. Each of these layers is backed with an 8 x 8 silicon photomultiplier diode (SiPM) array. The overall size of the imaging system is 27 mm x 27 mm x 135 mm. MCNPv6.1 and Geant4-10.04 were alternatively used to optimise the overall configuration and to investigate detection modalities. Results show promising performance with high precision source localisation and characterization abilities. Measurements were virtually obtained of two gamma-ray sources within steel enclosures at angles of 15°, 30° and 50° separation in order to test spatial resolution ability of the system. With the current active size of the system and the 8x8 SiPM configuration, the results estimate the spatial resolution to be close to 30°. The ability of the system to characterise and identify sources based on the type and energy of the radiation emitted, has been investigated and results show that for all radiation types the system can identify the source energy within the energy range of typical reported sources in literature.

scholarly journals A coincidence detection system based on real-time software

2016 ◽  
Vol 5 (2) ◽  
pp. 437-449 ◽  
Author(s):  
Sindulfo Ayuso ◽  
Juan José Blanco ◽  
José Medina ◽  
Raúl Gómez-Herrero ◽  
Oscar García-Población ◽  
...  
Keyword(s):  
Real Time ◽  
Detection System ◽  
Low Cost ◽  
Cosmic Ray ◽  
Coincidence Detection ◽  
Pulse Delay ◽  
Development Platform ◽  
Electronic Circuitry ◽  
Coincidence System ◽  
Cost Development

Abstract. Conventional real-time coincidence systems use electronic circuitry to detect coincident pulses (hardware coincidence). In this work, a new concept of coincidence system based on real-time software (software coincidence) is presented. This system is based on the recurrent supervision of the analogue-to-digital converters status, which is described in detail. A prototype has been designed and built using a low-cost development platform. It has been applied to two different experimental sets for cosmic ray muon detection. Experimental muon measurements recorded simultaneously using conventional hardware coincidence and our software coincidence system have been compared, yielding identical results. These measurements have also been validated using simultaneous neutron monitor observations. This new software coincidence system provides remarkable advantages such as higher simplicity of interconnection and adjusting. Thus, our system replaces, at least, three Nuclear Instrument Modules (NIMs) required by conventional coincidence systems, reducing its cost by a factor of 40 and eliminating pulse delay adjustments.

Threshold Radioactivity for Bulk Food Samples by Gamma Spectroscopy

1965 ◽  
Vol 48 (1) ◽  
pp. 1-5
Author(s):  
Harry M Yakabe ◽  
Hiram Neilson
Keyword(s):  
Gamma Ray ◽  
Gamma Spectroscopy ◽  
Rapid Determination ◽  
Detection System ◽  
Fission Products ◽  
Food Samples ◽  
Family Of Curves ◽  
Lower Limits ◽  
True Activity

Abstract In the surveillance of bulk food produce by gamma ray spectroscopy for fission products, the activities of the commonly observed radionuclides are frequently in the magnitude of background inherent to the detection system. The problems of determining whether the sample is in fact contaminated, the lower limits of detecting the radionuclides, and the effect of compton smear on the lower limits are discussed. The discussions are based on the modified spectrum stripping method for quantitative analysis of gamma ray spectrum for the following radioisotopes: Cs-137, Zr-95/Nb-95, and K-40. A family of curves are shown for rapid determination of the minimum detectable true activity (AII) of Cs-137.

REGULATION OF FACTOR V (FV) EXPRESSION IN HUMAN MEGAKARYOCYTES

1987 ◽  
Author(s):  
A Gewirtz ◽  
C L shepiro ◽  
R Bovd ◽  
R W Colman
Keyword(s):  
Cell Size ◽  
Detection System ◽  
Correlation Coefficients ◽  
Coefficient Of Determination ◽  
Maturation Stage ◽  
Factor V ◽  
Large Area ◽  
Dna Quantitation ◽  
Tetradecanoyl Phorbol Acetate

We have suggested that synthesis of FY by human megakaryocytes (MEGS), is a maturation relrted event. This is based on our finding that when MEGS are cloned from progenitor cells in vitro in FY depleted medium, FY is immunochemically detectable only in morphologically recognizable (mature) cells (Blood 67:1639, '86). The stimuli which induce FY synthesis in MEGS are unknown, but if they are related or linked to factors which regulate terminal maturation processes cellular FY levels might increase as the maturation routine proceeds. To test this hypothesis, mature human MEGS were isolated from normal bone marrow by counterflow centrifugel elutrietion, deposited onto gloss slides by cytocentri-fugation, and then fixed in methanol:acetone. Individual cells were then staged, geometric meon cell diometer (size) determined with on opticol fylor, end FY end DNA levels measured. FV expression in a large area of the MEG (38 urn in diameter) was semi-quantitated by microspectrophotometry (MSPEC) using a sensitive Texas Red labeled streptavidin-biotin detection system and a monoclonal antibody probe (B10) directed against the non-binding FY activation peptide (150,000 kd). Cells were then reacted with Chromomycin A3 to allow for simultaneous DNA quantitation by MSPEC in the same cell. Correlation coefficients (r) and coefficient of determination [r2] were computer generated to discern potential relationships between FY expression, and MEG maturation stage, size or ploidy level in a total of 532 MEGS. Characteristics of the population, and r/r2 vs. MEG FV content ere shown below:r/r2 values did not significantly change when total MEG FY content was measured in 100 additional MEGS. Therefore, MEG FY levels varied independently with cell size and ploidy, and did not appear to correlate with degree of mature MEG maturation as determined by standard critera. In two of four preliminary experiments, low dose (8nM ql2h × 4 doses) tetradecanoyl phorbol acetate augmented both the number of MEGS expressing FV, and the level of FY expressed per individual cell. We conclude from these data that once FV synthesis is initiated, FY synthesis and events relating to final cell size and ploidy development are regulated independently. Our data also suggest that MEG FV synthesis may be regulated in part by the phosphoinositide-protein kinase C system.

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