Fission chamber detector system for monitoring neutron flux in a nuclear reactor over an extra wide range, with high sensitivity in a hostile environment

1986 ◽  
Vol 12 (1-4) ◽  
pp. V
Keyword(s):  
Neutron Flux ◽  
Nuclear Reactor ◽  
High Sensitivity ◽  
Detector System ◽  
Hostile Environment ◽  
Fission Chamber ◽  
Wide Range

scholarly journals Thermal neutron intensity measurement with fission chamber in current, pulse and Campbell modes

2020 ◽  
Vol 231 ◽  
pp. 05009
Author(s):  
Shakir Zeinalov ◽  
Olga Sidorova ◽  
Pavel Sedyshev ◽  
Valery Shvetsov ◽  
Youngseok Lee ◽  
...  
Keyword(s):  
Neutron Flux ◽  
Thermal Neutron ◽  
Thermal Neutron Flux ◽  
Current Mode ◽  
Fission Chamber ◽  
Design Changes ◽  
Digital Pulse ◽  
Wide Range ◽  
Low Sensitivity ◽  
Digital Pulse Processing

In thermal nuclear reactors, most of the power is generated by thermal neutron induced fission. Therefore, fission chambers with targets that respond directly to slow neutrons are of great interest for thermal neutron flux measurements due to relatively low sensitivity to gamma radiation. However, the extreme conditions associated with experiments at very low cross section demand highly possible thermal neutron flux, leading often to substantial design changes. In this paper we report design of a fission chamber for wide range (from 10 to 1012 n/cm2 sec) measurement of thermal neutron flux. Test experiments were performed at the first beam of IBR2 pulsed reactor using digital pulse processing (DPP) technique with modern waveform digitizers (WFD). The neutron pulses detected by the fission chamber in each burst (5 Hz repetition rate) of the reactor were digitized and recorded to PC memory for further on-line and off-line analysis. New method is suggested to make link between the pulse counting, the current mode and the Campbell technique.

A New Detector System For The HB5 Stem Instrument

1985 ◽  
Vol 43 ◽  
pp. 134-135
Author(s):  
J.M. Cowley
Keyword(s):  
Dark Field ◽  
Detector System ◽  
Electron Holography ◽  
Small Specimen ◽  
Bright Field ◽  
Multiple Images ◽  
Practical Applications ◽  
Wide Range ◽  
Diffraction Patterns ◽  
Operational Modes

The HB5 STEM instrument at ASU has been modified previously to include an efficient two-dimensional detector incorporating an optical analyser device and also a digital system for the recording of multiple images. The detector system was built to explore a wide range of possibilities including in-line electron holography, the observation and recording of diffraction patterns from very small specimen regions (having diameters as small as 3Å) and the formation of both bright field and dark field images by detection of various portions of the diffraction pattern. Experience in the use of this system has shown that sane of its capabilities are unique and valuable. For other purposes it appears that, while the principles of the operational modes may be verified, the practical applications are limited by the details of the initial design.

scholarly journals Gold–Carbon Nanocomposites for Environmental Contaminant Sensing

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 719
Author(s):  
Shahrooz Rahmati ◽  
William Doherty ◽  
Arman Amani Babadi ◽  
Muhamad Syamim Akmal Che Mansor ◽  
Nurhidayatullaili Muhd Julkapli ◽  
...  
Keyword(s):  
Environmental Pollutants ◽  
High Sensitivity ◽  
Environmental Crisis ◽  
World Population ◽  
Chemical Contaminants ◽  
Carbon Nanocomposites ◽  
Minimal Sample ◽  
Wide Range ◽  
And Control ◽  
Analytical Tools

The environmental crisis, due to the rapid growth of the world population and globalisation, is a serious concern of this century. Nanoscience and nanotechnology play an important role in addressing a wide range of environmental issues with innovative and successful solutions. Identification and control of emerging chemical contaminants have received substantial interest in recent years. As a result, there is a need for reliable and rapid analytical tools capable of performing sample analysis with high sensitivity, broad selectivity, desired stability, and minimal sample handling for the detection, degradation, and removal of hazardous contaminants. In this review, various gold–carbon nanocomposites-based sensors/biosensors that have been developed thus far are explored. The electrochemical platforms, synthesis, diverse applications, and effective monitoring of environmental pollutants are investigated comparatively.

scholarly journals Pulsed Electromagnetic Cross-Well Exploration for Monitoring Permafrost and Examining the Processes of Its Geocryological Changes

Geosciences ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 60
Author(s):  
Viacheslav Glinskikh ◽  
Oleg Nechaev ◽  
Igor Mikhaylov ◽  
Kirill Danilovskiy ◽  
Vladimir Olenchenko
Keyword(s):  
High Performance ◽  
Geophysical Methods ◽  
Three Dimensional ◽  
High Sensitivity ◽  
Data Interpretation ◽  
Industrial Facilities ◽  
Wide Range ◽  
Vector Finite Element ◽  
A New Technique ◽  
Pulsed Electromagnetic

This paper is dedicated to the topical problem of examining permafrost’s state and the processes of its geocryological changes by means of geophysical methods. To monitor the cryolithozone, we proposed and scientifically substantiated a new technique of pulsed electromagnetic cross-well sounding. Based on the vector finite-element method, we created a mathematical model of the cross-well sounding process with a pulsed source in a three-dimensional spatially heterogeneous medium. A high-performance parallel computing algorithm was developed and verified. Through realistic geoelectric models of permafrost with a talik under a highway, constructed following the results of electrotomography field data interpretation, we numerically simulated the pulsed sounding on the computing resources of the Siberian Supercomputer Center of SB RAS. The simulation results suggest the proposed system of pulsed electromagnetic cross-well monitoring to be characterized by a high sensitivity to the presence and dimensions of the talik. The devised approach can be oriented to addressing a wide range of issues related to monitoring permafrost rocks under civil and industrial facilities, buildings, and constructions.

scholarly journals Overview of Popular Techniques of Raman Spectroscopy and Their Potential in the Study of Plant Tissues

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1537
Author(s):  
Aneta Saletnik ◽  
Bogdan Saletnik ◽  
Czesław Puchalski
Keyword(s):  
Raman Spectroscopy ◽  
Cell Walls ◽  
Structural Changes ◽  
Spatial Information ◽  
Technological Development ◽  
Analytical Techniques ◽  
High Sensitivity ◽  
Plant Tissues ◽  
Wide Range ◽  
Identification Technique

Raman spectroscopy is one of the main analytical techniques used in optical metrology. It is a vibration, marker-free technique that provides insight into the structure and composition of tissues and cells at the molecular level. Raman spectroscopy is an outstanding material identification technique. It provides spatial information of vibrations from complex biological samples which renders it a very accurate tool for the analysis of highly complex plant tissues. Raman spectra can be used as a fingerprint tool for a very wide range of compounds. Raman spectroscopy enables all the polymers that build the cell walls of plants to be tracked simultaneously; it facilitates the analysis of both the molecular composition and the molecular structure of cell walls. Due to its high sensitivity to even minute structural changes, this method is used for comparative tests. The introduction of new and improved Raman techniques by scientists as well as the constant technological development of the apparatus has resulted in an increased importance of Raman spectroscopy in the discovery and defining of tissues and the processes taking place in them.

Measurement of pulmonary edema in intact dogs by transthoracic gamma-ray attenuation

1979 ◽  
Vol 47 (6) ◽  
pp. 1228-1233 ◽  
Author(s):  
D. S. Simon ◽  
J. F. Murray ◽  
N. C. Staub
Keyword(s):  
Pulmonary Edema ◽  
Time Course ◽  
Gamma Ray ◽  
High Sensitivity ◽  
Lung Edema ◽  
Lung Water ◽  
Vascular Congestion ◽  
Isolated Lung ◽  
Wide Range ◽  
Gamma Ray Attenuation

We evaluated the attenuation of the 122 keV gamma ray of cobalt-57 across the thorax of anesthetized dogs as a method for following the time course of lung water changes in acute pulmonary edema induced by either increased microvascular permeability or increased microvascular hydrostatic pressure. The gamma rays traversed the thorax centered on the seventh rib laterally where the lung mass in the beam path was greatest. Calibration measurements in isolated lung lobes demonstrated the high sensitivity and inherent accuracy of the method over a wide range of lung water contents. In control dogs reproducibility averaged +/-3%. Increased permeability edema led to large rapid increases in the transthoracic gamma ray attenuation (TGA), while increased pressure caused an immediate, modest increase in TGA (vascular congestion) followed by a slow further increase over 2 h. There was a fairly good correlation between the increase in extravascular lung water and the change in TGA. The method is simple, safe, and noninvasive and appears to be useful for following the time course of lung water accumulation in generalized lung edema in anesthetized animals.

scholarly journals Measurement and analysis of gas-puff density distributions for plasma radiation source z pinches

2001 ◽  
Vol 19 (4) ◽  
pp. 579-595 ◽  
Author(s):  
D. MOSHER ◽  
B.V. WEBER ◽  
B. MOOSMAN ◽  
R.J. COMMISSO ◽  
P. COLEMAN ◽  
...  
Keyword(s):  
Radiation Source ◽  
Gas Flow ◽  
Initial Density ◽  
High Sensitivity ◽  
Plasma Radiation ◽  
Analysis Techniques ◽  
Density Distributions ◽  
Radiation Properties ◽  
Wide Range ◽  
Measurement And Analysis

High-sensitivity interferometry measurements of initial density distributions are reviewed for a wide range of gas-puff nozzles used in plasma radiation source (PRS) z-pinch experiments. Accurate gas distributions are required for determining experimental load parameters, modeling implosion dynamics, understanding the radiation properties of the stagnated pinch, and for predicting PRS performance in future experiments. For a number of these nozzles, a simple ballistic-gas-flow model (BFM) has been used to provide good physics-based analytic fits to the measured r, z density distributions. These BFM fits provide a convenient means to smoothly interpolate radial density distributions between discrete axial measurement locations for finer-zoned two-dimensional MHD calculations, and can be used to determine how changes in nozzle parameters and load geometry might alter implosion dynamics and radiation performance. These measurement and analysis techniques are demonstrated for a nested-shell nozzle used in Double Eagle and Saturn experiments. For this nozzle, the analysis suggests load modifications that may increase the K-shell yield.

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