Characteristics of Flow Proportional Counters for X-Rays

1966 ◽  
Vol 10 ◽  
pp. 534-545 ◽  
Author(s):  
N. Spielberg
Keyword(s):  
Counting Rate ◽  
Pulse Height ◽  
Operating Conditions ◽  
Design Parameters ◽  
Clear Understanding ◽  
Operating Voltage ◽  
Height Distribution ◽  
Operating Pressure ◽  
X Rays ◽  
Proportional Counters

AbstractGas flow proportional counters for the detection of soft X-rays were introduced about ten years ago. These detectors offered the advantages of high sensitivity, good energy discrimination qualities and the ability to handle high counting rates. Since that time they have been used for ultra-soft and harder X-rays as well, both as detectors in standard spectrographic instruments and as energy discriminating instruments themselves in various so-called nondispersive applications. Depending upon the particular instrumental application, however, their use has led to considerable complication of the associated electronic circuitry in order to realize their advantages. For the most effective use of these counters (and of sealed proportional counters as well) it is necessary to have a clear understanding of the effect of various design parameters and operating conditions on their performance. The dependence of the shape of the pulse height distribution on the operating voltage, pressure and counting rate is described as a function of the energy of the radiation detected and the nature of the gas. Stability requirements on. counter tube high voltage supplies and operating pressure are discussed. Shifts of pulse height distributions toward smaller pulse sizes with increasing counting rate are described and the dependence of these shifts on the various parameters and on wavelength are discussed. Techniques for eliminating the shifts and the implications of these techniques for the associated electronics are described.

THE RESOLUTION CORRECTION IN THE SCINTILLATION SPECTROMETRY OF CONTINUOUS X RAYS

1958 ◽  
Vol 36 (12) ◽  
pp. 1624-1633 ◽  
Author(s):  
W. R. Dixon ◽  
J. H. Aitken
Keyword(s):  
Integral Equation ◽  
Numerical Analysis ◽  
Numerical Methods ◽  
Analytical Procedure ◽  
Pulse Height ◽  
Matrix Inversion ◽  
Height Distribution ◽  
X Rays ◽  
Smooth Solutions ◽  
Pulse Height Distribution

The problem of making resolution corrections in the scintillation spectrometry of continuous X rays is discussed. Analytical solutions are given to the integral equation which describes the effect of the statistical spread in pulse height. The practical necessity of making some kind of numerical analysis is pointed out. Difficulties with numerical methods arise from the fact that the observed pulse-height distribution cannot be defined precisely. As a result it is possible in practice only to find smooth "solutions". Additional difficulties arise if the numerical method is based on an invalid analytical procedure. For example matrix inversion is of doubtful value in making the resolution correction because there does not appear to be an inverse kernel for the integral equation in question.

scholarly journals Study of Background Pulse Spectrum of an LSC System

Radiocarbon ◽  
1989 ◽  
Vol 31 (03) ◽  
pp. 342-351 ◽  
Author(s):  
Sigurđur A Einarsson ◽  
Páll Theodórsson
Keyword(s):  
Counting Rate ◽  
Liquid Scintillation ◽  
Collection Efficiency ◽  
Pulse Height ◽  
Pulse Height Spectrum ◽  
Light Collection ◽  
Background Counting Rate ◽  
Proportional Counters ◽  
Background Counting ◽  
Made In

Important advances have been made in reducing the background counting rate of gas proportional counters for14C dating through detailed and systematic study of the background components. Until recently, limited work has been reported on the study of the background of liquid scintillation counters (LSC). During the last few years, commercial systems with greatly reduced background have been introduced. It is shown that the best gas proportional counters and LSC have similar backgrounds for the same amount of sample material. Similar results with less effort may be expected with more detailed and fundamental knowledge of the components of the background of LSC. We report the results of a study of one photomultiplier LSC system where we research all parameters of importance: light collection efficiency, absorbed energy per photo-electron, pulse height spectrum and background counting rate.

THE PULSE HEIGHT DISTRIBUTION FROM BORON TRIFLUORIDE PROPORTIONAL COUNTERS IRRADIATED WITH 4.87-MEV. NEUTRONS

1955 ◽  
Vol 33 (5) ◽  
pp. 219-224 ◽  
Author(s):  
D. B. James ◽  
W. Kubelka ◽  
S. A. Heiberg ◽  
J. B. Warren
Keyword(s):  
Fast Neutron ◽  
Boron Trifluoride ◽  
Pulse Height ◽  
The Other ◽  
Height Distribution ◽  
Q Value ◽  
Pulse Height Distribution ◽  
Neutron Spectra ◽  
Proportional Counters ◽  
Q Values

Two boron trifluoride proportional counters, one containing normal isotopic boron and the other containing boron enriched to 96% B10, have been irradiated with 4.87-Mev. neutrons from the reaction D(d, n)He3. In addition to the reactions B10(n, α)Li7 and B10(n, α)Li7* with Q-values of 2.79 Mev. and 2.31 Mev. respectively, two other reactions have been observed. These are (i) F19(n, α)N16* with a Q-value of −1.77 ± 0.15 Mev. and (ii) either B10(n, p)Be10 or, much more probably, B10(n, t)Be8 with a Q-value of 0.35 ± 0.20 Mev. Owing to the presence of these two reactions, the analysis of complex fast-neutron spectra by the use of such counters is not feasible.

CARBON CAPTURE AND STORAGE ENERGY CONSUMPTION AND PERFORMANCE OPTIMIZATION USING METAMODELS AND RESPONSE SURFACE METHODOLOGY

2021 ◽  
pp. 1-28
Author(s):  
Ali Allahyarzadeh-Bidgoli ◽  
Nayereh Hamidishad ◽  
Jurandir Itizo Yanagihara
Keyword(s):  
Power Consumption ◽  
Co2 Emissions ◽  
Performance Optimization ◽  
Operating Conditions ◽  
Design Parameters ◽  
Separation Performance ◽  
Co2 Removal ◽  
Operating Pressure ◽  
Heating And Cooling ◽  
And Storage

Abstract Oil and gas industries have high carbon dioxide (CO2) emissions, which is a great environmental concern. Monoethanolamine (MEA) is widely used as a solvent in CO2 capture and storage (CCS) systems. The challenge is that MEA–CCS itself is an energy-intensive process that requires optimum configuration and operation, and numerous design parameters and heat demands must be considered. Thus, the current work evaluates the energy distributions and CO2 removal efficiency of a CCS installed in floating production storage and offloading units under different operating conditions of a power- and heat-generation hub. The optimization procedures are implemented using highly accurate surrogate models for the following responses: 1) overall power consumption of CCS, 2) CCS separation performance, and 3) CCS heating and cooling demands. The input variables considered in the present research include the following: 1) the exhaust gas compositions and mass flow rate, 2) the operating pressure and temperature parameters of CCS and the injection compression unit, 3) the structural parameters of absorber and stripper columns, and 4) MEA solution parameters. The optimum CCS configuration significantly reduces the total heating and cooling demands by 62.77% (7 × 106 kW) and the overall power consumption by 8.65 % (1.8 MW), and it increases the CCS separation performance by 4.46% (97.46%) and mitigates the CO2 emissions of proper CCS by 1.02 t/h compared with conventional operating conditions.

Coupled Thermal-Structural-Fluid Numerical Analysis of Gas Lubricated Mechanical Seals

2018 ◽  
Author(s):  
Jingjing Luo ◽  
Hans Josef Dohmen ◽  
Friedrich-Karl Benra
Keyword(s):  
Numerical Analysis ◽  
Hydrodynamic Pressure ◽  
Operating Conditions ◽  
Design Parameters ◽  
Transfer Model ◽  
Operating Pressure ◽  
Mechanical Seals ◽  
Choked Flow ◽  
Leakage Flows ◽  
Mechanical Deformations

With the increase of the operating pressure of gas compressors, the demand for a robust and reliable shaft end sealing solution, namely dry gas seal, has risen. The narrow sealing gap formed between the rotating and the stationary rings, about 2–5 micrometers wide, is subject to the hydrodynamic pressure on sealing surfaces and deflections on both rings due to mechanical forces and thermal loads. In order to estimate the seal performance in terms of film thicknesses, leakage flows and radial tapers, a numerical program which automatically couples the simulation of the pressure field in micro-scale based on the Reynolds equation for compressible fluids, the heat generation and transfer model between the fluid and solids as well as the structural and thermal distortion of both rings, has been developed by the authors to address the mechanical seal problem as a whole system. In this way, the interaction of all arising forces, mechanical deformations and thermal deviations is taken into account in the design process of the seals. The choked flow exit boundary is also taken into considerations for high pressure conditions. The method to solve this interactive problem as a whole is discussed. The paper presents the numerical analysis carried out with various groove parameters, seal geometries and operating conditions. Results are compared and show a good agreement with actual experimental data. Design parameters which have strong influences on the seal performance are as well discussed.

Effect of operating conditions on rejection of anionic pollutants in the water environment by nanofiltration especially in very low pressure range

1996 ◽  
Vol 34 (9) ◽  
pp. 149-156 ◽  
Author(s):  
C. Ratanatamskul ◽  
K. Yamamoto ◽  
T. Urase ◽  
S. Ohgaki
Keyword(s):  
Water Environment ◽  
Chloride Ions ◽  
Operating Conditions ◽  
Transmembrane Pressure ◽  
Operating Pressure ◽  
Nanofiltration Membranes ◽  
Single Solution ◽  
Crossflow Velocity ◽  
Membrane Type ◽  
New Generation

The recent development of new generation LPRO or nanofiltration membranes have received attraction for application in the field of wastewater and water treatment through an increasingly stringent regulation for drinking purpose and water reclamation. In this research, the application on treatment of anionic pollutants (nitrate, nitrite, phosphate, sulfate and chloride ions) have been investigated as functions of transmembrane pressure, crossflow velocity and temperature under very much lower pressure operation range (0.49 to 0.03 MPa) than any other previous research used to do. Negative rejection was also observed under very much low range of operating pressure in the case of membrane type NTR-7250. Moreover, the extended Nernst-Planck model was used for analysis of the experimental data of the rejection of nitrate, nitrite and chloride ions in single solution by considering effective charged density of the membranes.

Energy-dependent dead-time correction in digital pulse processors applied to silicon drift detector's X-ray spectra

2018 ◽  
Vol 25 (2) ◽  
pp. 484-495 ◽  
Author(s):  
Suelen F. Barros ◽  
Vito R. Vanin ◽  
Alexandre A. Malafronte ◽  
Nora L. Maidana ◽  
Marcos N. Martins
Keyword(s):  
Dead Time ◽  
Pulse Height ◽  
Height Distribution ◽  
Pulse Height Distribution ◽  
Dead Time Correction ◽  
Time Model ◽  
X Ray ◽  
Digital Pulse ◽  
Analytical Correction ◽  
Energy Dependent

Dead-time effects in X-ray spectra taken with a digital pulse processor and a silicon drift detector were investigated when the number of events at the low-energy end of the spectrum was more than half of the total, at counting rates up to 56 kHz. It was found that dead-time losses in the spectra are energy dependent and an analytical correction for this effect, which takes into account pulse pile-up, is proposed. This and the usual models have been applied to experimental measurements, evaluating the dead-time fraction either from the calculations or using the value given by the detector acquisition system. The energy-dependent dead-time model proposed fits accurately the experimental energy spectra in the range of counting rates explored in this work. A selection chart of the simplest mathematical model able to correct the pulse-height distribution according to counting rate and energy spectrum characteristics is included.

Sign in / Sign up

Export Citation Format

Share Document