scholarly journals Intrinsic background radiation of LaBr3(Ce) detector via coincidence measurements and simulations

2020 ◽  
Vol 31 (10) ◽  
Author(s):  
Hao Cheng ◽  
Bao-Hua Sun ◽  
Li-Hua Zhu ◽  
Tian-Xiao Li ◽  
Guang-Shuai Li ◽  
...  
Keyword(s):  
Background Radiation ◽  
Coincidence Measurements ◽  
Intrinsic Background

scholarly journals Performance of an uncooled imaging interferometric spectrometer with intrinsic background radiation

2021 ◽  
Vol 60 (03) ◽  
Author(s):  
Ingmar G. E. Renhorn ◽  
Thomas Svensson ◽  
Glenn D. Boreman
Keyword(s):  
Background Radiation ◽  
Intrinsic Background

Effect of intrinsic background radiation on the operation of a Fourier spectroradiometer

2003 ◽  
Vol 70 (5) ◽  
pp. 317
Author(s):  
S. K. Dvoruk ◽  
I. N. Efimov ◽  
V. N. Kornienko ◽  
I. V. Kochikov ◽  
M. V. Lelkov ◽  
...  
Keyword(s):  
Background Radiation ◽  
Intrinsic Background

Identification of Asbestos Fibres in a Water Sample by X-Ray Microanalysis

1975 ◽  
Vol 33 ◽  
pp. 274-275
Author(s):  
K. A. Brookes ◽  
D. Finbow ◽  
Madeleine Samuel
Keyword(s):  
Water Sample ◽  
Background Radiation ◽  
X Ray ◽  
Left Hand ◽  
Transmission Imaging ◽  
Different Types ◽  
Normal Specimen ◽  
Liquid Nitrogen Cooling ◽  
Normal Transmission ◽  
Additional Port

Investigation of the particulate matter contained in the water sample, revealed the presence of a number of different types and certain of these were selected for analysis.An A.E.I. Corinth electron microscope was modified to accept a Kevex Si (Li) detector. To allow for existing instruments to be readily modified, this was kept to a minimum. An additional port is machined in the specimen region to accept the detector, with the liquid nitrogen cooling dewar conveniently housed in the left hand cupboard adjacent to the microscope column. Since background radiation leads to loss in the sensitivity of the instrument, great care has been taken to reduce this effect by screening and manufacturing components that are near the specimen from material of low atomic number. To change from normal transmission imaging to X-ray analysis, the special 4-position specimen rod is inserted through the normal specimen airlock.

Digital x-ray mapping of nanometer-size supported bimetallic catalysts

1988 ◽  
Vol 46 ◽  
pp. 530-531
Author(s):  
L. T. Germinario
Keyword(s):  
Background Radiation ◽  
Metal Cluster ◽  
Single Element ◽  
Beam Diameter ◽  
X Rays ◽  
X Ray ◽  
Major Interest ◽  
Induced Changes

Understanding the role of metal cluster composition in determining catalytic selectivity and activity is of major interest in heterogeneous catalysis. The electron microscope is well established as a powerful tool for ultrastructural and compositional characterization of support and catalyst. Because the spatial resolution of x-ray microanalysis is defined by the smallest beam diameter into which the required number of electrons can be focused, the dedicated STEM with FEG is the instrument of choice. The main sources of errors in energy dispersive x-ray analysis (EDS) are: (1) beam-induced changes in specimen composition, (2) specimen drift, (3) instrumental factors which produce background radiation, and (4) basic statistical limitations which result in the detection of a finite number of x-ray photons. Digital beam techniques have been described for supported single-element metal clusters with spatial resolutions of about 10 nm. However, the detection of spurious characteristic x-rays away from catalyst particles produced images requiring several image processing steps.

Design of a UHV STEM for Through-The-Lens Electron Spectroscopy

1990 ◽  
Vol 48 (2) ◽  
pp. 380-381
Author(s):  
A. J. Bleeker ◽  
P. Kruit
Keyword(s):  
Secondary Electron ◽  
High Vacuum ◽  
Secondary Electron Emission ◽  
Auger Spectroscopy ◽  
Scanning Transmission Electron Microscope ◽  
Point Of View ◽  
Ultra High Vacuum ◽  
Scanning Transmission ◽  
Auger Spectra ◽  
Coincidence Measurements

Combining of the high spatial resolution of a Scanning Transmission Electron Microscope and the wealth of information from the secondary electrons and Auger spectra opens up new possibilities for materials research. In a prototype instrument at the Delft University of Technology we have shown that it is possible from the optical point of view to combine STEM and Auger spectroscopy [1]. With an Electron Energy Loss Spectrometer attached to the microscope it also became possible to perform coincidence measurements between the secondary electron signal and the EELS signal. We measured Auger spectra of carbon aluminium and Argon gas showing energy resolutions better than 1eV [2]. The coincidence measurements on carbon with a time resolution of 5 ns yielded basic insight in secondary electron emission processes [3]. However, for serious Auger spectroscopy, the specimen needs to be in Ultra High Vacuum. ( 10−10 Torr ). At this moment a new setup is in its last phase of construction.

Cosmological Consequences with Randers Conformal of Finsler space

2007 ◽  
Vol 3 (2) ◽  
pp. 203-211
Author(s):  
Arunesh Pandey ◽  
R K Mishra
Keyword(s):  
Background Radiation ◽  
Finsler Space ◽  
Space Time ◽  
Anisotropic Model ◽  
Microwave Background ◽  
Microwave Background Radiation

In this paper we study an anisotropic model of space – time with Finslerian metric. The observed anisotropy of the microwave background radiation is incorporated in the Finslerian metric of space time.

A Study of Exposure of Overall Background Radiation In Syangja District of Nepal

2017 ◽  
pp. 92-95
Author(s):  
T Timilsina ◽  
K. R. Poudel ◽  
P. R. Poudel
Keyword(s):  
High Altitude ◽  
Background Radiation ◽  
Significant Risk ◽  
Total Radiation ◽  
Radiation Level ◽  
The People ◽  
Public Exposure

This study presents general exposure of background radiation to the people living or visiting nine places of Syangja district. A portable GM counter was used to quantify the total radiation at those places. The findings of this study show variation of radiation level at different places. Comparatively large values of radiation counts are observed at high altitude places (Gurung Dada: 70.23 cpm and Pokhari Dada: 64.77 cpm). The value of radiation count inside room is comparatively larger than that at outside room for these places. Moreover, small value of radiation count is observed at river side (Bank of Aandhikhola river: 21.63 cpm). Little large values are observed near Saligram stones and ancient statue than at other regions of one historical/religious place. Hence, results show fluctuations of background radiation level for different places. Some places have comparatively large value of radiation count while some places have comparatively small value. But there is no any abnormal value of radiation counts for all sample places. So there is, generally, no significant risk of public exposure to the background radiation for sample places.The Himalayan Physics Vol. 6 & 7, April 2017 (92-95)

Screening of Extremophile Microalgae Isolated from High Background Radiation Areas as Source of Bioactive Materials

2020 ◽  
Vol 16 (4) ◽  
pp. 407-414
Author(s):  
Fatemeh Heidari ◽  
Zeinab Shariatmadari ◽  
Hossein Riahi
Keyword(s):  
Antioxidant Activity ◽  
Hot Springs ◽  
Background Radiation ◽  
Cadmium Stress ◽  
Total Phenol ◽  
Total Phenolic ◽  
Extreme Conditions ◽  
Unicellular Cyanobacterium ◽  
High Background ◽  
Cadmium Adsorption

Background: Microalgae are the source of various compounds with high potentials for being used in different industries. The production of such compounds can be raised under extreme conditions. In the present study, four cyanobacteria and one coccoid green alga were examined which were isolated from hot springs in high background radiation areas in Ramsar, a city in the north of Iran. Methods: Cadmium adsorption from aqueous solution, response towards cadmium stress, antioxidant activity, total phenolic compound and drought tolerance were investigated in these microalgae. Results: The results showed that these extremophile microalgae contain valuable biological compounds which can be useful in remediation of heavy metals from contaminated water and soils and pharmaceutical applications. The unicellular cyanobacterium, Chroococidiopsis thermalis IBRC-M50002, was the best strain with the highest biological activity in various testes such as cadmium adsorption (225 mg g-1), cadmium tolerance stress (100 mg ml-1), antioxidant activity (IC50= 18 μg mg-1) and total phenol content (100 μg ml-1). The coccoid green algae Grasiella emersonii IBRC-M50001, also exhibited significant antioxidant activity (IC50=10 μg mg-1) and total phenol compound (116 μg ml-1), but its cadmium adsorption, tolerance at cadmium stress and desiccation were lower than Chroococidiopsis thermalis. Conclusion: HBRAs microalgae, isolated from extreme conditions, are useful microorganisms for the production of bioactive substances and natural antioxidants. In other words, they exhibited high capacity to be used in pharmaceutical, industrial and commercial applications.

The experience of employment of the mathematical cartography methods in cosmology

2017 ◽  
Vol 923 (5) ◽  
pp. 7-16
Author(s):  
A.V. Kavrayskiy
Keyword(s):  
Background Radiation ◽  
Three Dimensional ◽  
Spherical Coordinates ◽  
Linear Element ◽  
Microwave Background ◽  
Euclidian Space ◽  
Microwave Background Radiation ◽  
Rectangular Coordinates ◽  
The Universe ◽  
Length Distortion

The experience of mathematical modeling of the 3D-sphere in the 4D-space and projecting it by mathematical cartography methods in the 3D-Euclidian space is presented. The problem is solved by introduction of spherical coordinates for the 3D-sphere and their transformation into the rectangular coordinates, using the mathematical cartography methods. The mathematical relationship for calculating the length distortion mp(s) of the ds linear element when projecting the 3D-sphere from the 4-dimensional Euclidian space into three-dimensional Euclidian space is derived. Numerical examples, containing the modeling of the ds small linear element by spherical coordinates of 3D-sphere, projecting this sphere into the 3D-Euclidian space and length of ds calculating by means of its projection dL and size of distortion mp(s) are solved. Based on the model of the Universe known in cosmology as the 3D-sphere, the hypothesis of connection between distortion mp(s) and the known observed effects Redshift and Microwave Background Radiation is considered.

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