scholarly journals Energy calibration of He-3, He-4 Neutron Proportional Counters

2020 ◽  
Vol 13 ◽  
pp. 222
Author(s):  
M. Manolopoulou ◽  
M. Fragopoulou ◽  
S. Stoulos ◽  
C. Koukorava ◽  
M. Zamani
Keyword(s):  
Linear Dependence ◽  
Proportional Counter ◽  
Pulse Shaping ◽  
Gamma Ray ◽  
Energy Calibration ◽  
Tandem Accelerator ◽  
Neutron Spectra ◽  
Shaping Time ◽  
Energy Peak ◽  
Proportional Counters

Two helium filled proportional counters (He-3, He-4) were irradiated with neu- trons in the energy range 0.025 eV - 10.7 MeV, in the Tandem accelerator, NCSR Demokritos, Athens. The full energy peak in He-3 proportional counter as well as the recoil peaks in He-3 and He-4 counters show linear dependence with neutron energy. A study of gamma ray contribution to the neutron spectra of He-4 counter was performed as a function of the pulse shaping time.

scholarly journals Novel concept for neutron detection: proportional counter filled with 10B nanoparticle aerosol

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
F. D. Amaro ◽  
C. M. B. Monteiro ◽  
J. M. F. dos Santos ◽  
A. Antognini
Keyword(s):  
Proportional Counter ◽  
Gamma Ray ◽  
Detection Efficiency ◽  
Radiation Detection ◽  
Neutron Detection ◽  
Nuclear Material ◽  
Sensitive Material ◽  
Proportional Counters ◽  
Thermal Neutron Beam ◽  
Novel Concept

Abstract The high neutron detection efficiency, good gamma-ray discrimination and non-toxicity of 3He made of proportional counters filled with this gas the obvious choice for neutron detection, particularly in radiation portal monitors (RPM), used to control the illicit transport of nuclear material, of which neutron detectors are key components. 3He is very rare and during the last decade this gas has become increasingly difficult to acquire. With the exception of BF3, which is toxic, no other gas can be used for neutron detection in proportional counters. We present an alternative where the 3He atoms are replaced by nanoparticles made of another neutron sensitive material, 10B. The particles are dispersed in a gaseous volume, forming an aerosol with neutron sensitive properties. A proportional counter filled with such aerosol was exposed to a thermal neutron beam and the recorded response indicates that the neutrons have interacted with the particles in the aerosol. This original technique, which transforms a standard proportional gas mixture into a neutron sensitive aerosol, is a breakthrough in the field of radiation detection and has the potential to become an alternative to the use of 3He in proportional counters.

A NEW GAMMA TRANSITION FOLLOWING THE DECAY OF 2.4-MINUTE 108AG

1964 ◽  
Vol 42 (11) ◽  
pp. 2173-2179 ◽  
Author(s):  
H. W. Taylor ◽  
T. A. Eastwood
Keyword(s):  
Decay Time ◽  
Gamma Ray ◽  
Gamma Transition ◽  
Full Energy Peak ◽  
Full Energy ◽  
Low Intensity ◽  
Energy Peak ◽  
Gamma Coincidence

A low-intensity peak has been found at 1010 ± 30 keV in the gamma-ray spectrum of 2.4-minute 108Ag obtained with NaI scintillation spectrometers. Consideration of the source-to-crystal distance as well as the effects of absorbers and decay time shows that it is the full-energy peak of a 1010 ± 30 keV gamma ray emitted by 108Ag. Gamma–gamma coincidence studies indicate that this gamma transition occurs between a new level at 1433 ± 30 and the 433-keV level of 108Pd.

scholarly journals Attempted study of the 237Np(n,2n)236Np reaction cross section at 9.5 MeV

2019 ◽  
Vol 18 ◽  
pp. 101
Author(s):  
M. Diakaki ◽  
R. Vlastou ◽  
M. Kokkoris ◽  
C. T. Papadopoulos ◽  
A. Tsinganis ◽  
...  
Keyword(s):  
Cross Section ◽  
Gamma Ray ◽  
Gamma Spectroscopy ◽  
Reaction Cross ◽  
Activation Technique ◽  
Incident Neutron ◽  
Incident Neutron Energy ◽  
Tandem Accelerator ◽  
Section Measurement ◽  
High Gamma

The cross section measurement of the 237Np(n,2n)236Np reaction has been attempted at an incident neutron energy of 9.5 MeV by means of the activation technique. The neutron beam was produced via the 2H(d,n)3Ηe reaction at the VdG Tandem accelerator of NCSR “Demokritos”. It is the second time that this measurement has been tried with a gamma spectroscopy method and the difficulties faced due to the high gamma ray background produced by the sample itself and the fission fragments produced by the irradiation, in combination with the very low intensity of the gamma ray of interest are being reported.

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 University of Washington Dates IV

Radiocarbon ◽  
1976 ◽  
Vol 18 (2) ◽  
pp. 221-239 ◽  
Author(s):  
A W Fairhall ◽  
A W Young ◽  
J L Erickson
Keyword(s):  
Oxalic Acid ◽  
Proportional Counter ◽  
Counting Rate ◽  
Sea Water ◽  
Differential Pressure ◽  
Dead Volume ◽  
Active Volume ◽  
The Third ◽  
Proportional Counters ◽  
Anticoincidence Counting

The dates reported in this list are for geologic and archaeologic samples only. During the interval since our last date list (R, 1966, v 8, p 498-506) most of our measurements have been on samples of sea water. These will be reported separately at a later time. The methods used are essentially those reported previously (R, 1963, v 5, p 80-81) but with the following notable changes and additions: We now prepare our methane counting gas as described in Buddemeier et al (1970). Our IL membrane counter has since been augmented by 3 additional counters. Two of these are IL quartz proportional counters inside geiger anticoincidence shields. Operating pressures are ca 1.5 to 4atm. Backgrounds of these 2 counters are in the neighborhood of 1.8 and 3cpm and the net counting rate of NBS oxalic acid ranges from 7 to 18.7cpm, depending on the pressure. The third counter (“minicounter”) is rather special: .IL quartz proportional counter inside a methane proportional anticoincidence counter. Sample and anticoincidence counting gases are introduced simultaneously with a differential pressure that never exceeds a few cm Hg. The sample filling side is constructed so as to minimize dead volume; over 80% of the sample gas is inside the active volume of the 14C counter. The range of filling pressures which are possible is ca 1 to 4atm.

Proportional Counter Parameters

1972 ◽  
Vol 16 ◽  
pp. 37-52 ◽  
Author(s):  
A. J. Burek ◽  
R. L. Blake
Keyword(s):  
Proportional Counter ◽  
X Rays ◽  
X Ray ◽  
Proportional Counters

AbstractA flow proportional counter for ultrasoft x-ray applications has been constructed and used to measure proportional counter parameters in the ultrasoft x-ray region at atmospheric and subatmospheric pressures for counting gases of P-10 and methane. We find that at atmospheric pressures the parametrization given by Zastawny for describing gas amplification in proportional counters applies and have measured values for the parameters for P-10 and methane. For subatmospheric pressures the Zastawny parameters are inadequate. A new parametrizatlon is required. In addition, the linearity of the detector for x-rays of energies of 15 KeV to 0.5 KeV was measured for pressures ranging from 750 Torr to 150 Torr and found to be excellent in all pressure regions.

Reduction of False Positives in the Identification of Nuclides in Environmental Samples

2003 ◽  
Author(s):  
Susan E. Haywood
Keyword(s):  
Environmental Samples ◽  
Free Parameter ◽  
Gamma Ray ◽  
Large Range ◽  
False Positives ◽  
Energy Calibration ◽  
Average Error ◽  
Peak Activity ◽  
Analysis Method ◽  
Decay Products

Gamma-ray spectra containing peaks that are too close in energy for deconvolution to be done accurately are best analyzed by a library-based method. However, a library-based analysis done with a large library may result an unacceptable number of false positives being reported. A normal working library suitable for analyzing environmental samples containing unknown materials may have over 1000 peaks, many of which are too close for deconvolution to be done accurately. A program has been written that uses a library-based analysis method that reduces the reporting of false positives, while retaining the ability to identify isotopes accurately from a large range of possibilities. In addition, the peak area calculation has been improved by allowing the energy calibration to be a free parameter in the fit of individual multiplets. This peak area improvement can result in a change of activity of several percent for some nuclides. In some cases, shifting the multiplet position can reduce false positives by identifying a peak in the multiplet as an unknown rather than associating it with a nuclide. One spectrum showed a marked peak activity improvement when the calibration was allowed to shift even though the the average error in the original calibration was 0.08%. Results obtained from a study on the identification of uranium decay products are presented.

scholarly journals X-Ray Astronomy Satellite Ginga

1990 ◽  
Vol 123 ◽  
pp. 41-48
Author(s):  
F. Makino
Keyword(s):  
Gamma Ray ◽  
Effective Area ◽  
X Rays ◽  
Scientific Instruments ◽  
Large Area ◽  
Gamma Ray Burst ◽  
X Ray ◽  
Proportional Counters ◽  
Main Instrument

AbstractThe X-ray astronomy satellite Ginga carries three scientific instruments, the Large Area proportional Counters (LAC), All Sky X-ray Monitor (ASM) and Gamma-ray Burst Detector (GBD). The LAC is the main instrument with an effective area of 4000 cm2 giving it the highest sensitivity to hard X-rays so far achieved. Ginga observed about 250 targets up to the end of 1989.

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