A STUDY OF THE GAMMA RADIATION FOLLOWING NEUTRON CAPTURE IN COPPER

1967 ◽  
Vol 45 (7) ◽  
pp. 2395-2408 ◽  
Author(s):  
A. H. Colenbrander ◽  
T. J. Kennett
Keyword(s):  
Gamma Radiation ◽  
Gamma Rays ◽  
Neutron Capture ◽  
Gamma Ray ◽  
Copper Target ◽  
Coincidence Measurements

The neutron capture gamma-ray spectrum for a natural copper target has been investigated using a Ge(Li) spectrometer. A total of 146 gamma rays were observed, of which about half have been isotopically assigned. Assignment was achieved through the use of coincidence measurements and (d, p) results. The neutron separation energies were found to be 7 914(3) and 7 063(3) keV for 64Cu and 66Cu respectively. The 66Cu gamma-ray transition to low-lying states exhibit exceptionally large radiation widths in a manner similar to the corresponding anomaly in 64Cu.

LOGGING OF DRILL HOLES BY THE NEUTRON, GAMMA METHOD, AND GAMMA RAY SCATTERING

Geophysics ◽  
1951 ◽  
Vol 16 (2) ◽  
pp. 260-276 ◽  
Author(s):  
Henry Faul ◽  
C. W. Tittle
Keyword(s):  
Gamma Radiation ◽  
Neutron Source ◽  
Gamma Rays ◽  
Hydrogen Content ◽  
Neutron Capture ◽  
Gamma Ray ◽  
Drilling Mud ◽  
Favorable Conditions ◽  
Drill Holes ◽  
Gamma Intensity

The intensity distribution of secondary gamma radiation resulting from neutron capture has been measured in simulated drill holes, of various types such as cased and uncased, empty and water‐filled. The intensity of neutron‐capture gamma rays depends on the hydrogen content of the rock. In a six‐inch well, it increases with hydrogen content at points within about 16 inches of the neutron source and decreases at more distant points. The absolute gamma intensity is greatly reduced when non‐hydrogenous gamma‐ray or neutron absorbers, e.g., lead or boron are introduced between logging probe and formation. The slope of logarithmic gamma ray intensity vs. distance remains virtually constant. It changes with the hydrogen content of the formation and offers a means of quantitatively estimating porosity behind casing despite extraneous absorption. The slope can be measured automatically in the well by two gamma detectors placed in a probe at fixed distances from a neutron source. Hydrogenous material between probe and rock increases the slope. Two or three inches of drilling mud seriously impair the sensitivity. Gamma radiation scattered by the walls of drill holes necessitates proper shielding for detectors used in (n, γ) logging with a radium‐beryllium source. A shielded detector is predominantly sensitive to the hard neutron‐capture gamma rays and tends to discriminate against the softer scattered radiation. The scattered intensity decreases with increasing bulk density of the formation. Under favorable conditions, continuous logs of formation density as a function of depth can be obtained.

scholarly journals Partial and total thermal neutron capture cross sections for non-destructive assay and transmutation monitoring of 99Tc

2002 ◽  
Vol 90 (8) ◽  
Author(s):  
G. L. Molnár ◽  
T. Belgya ◽  
Zs. Révay ◽  
Syed M. Qaim
Keyword(s):  
Gamma Rays ◽  
Cross Sections ◽  
Neutron Capture ◽  
Gamma Ray ◽  
Cold Neutron ◽  
Production Cross ◽  
Radioactive Product ◽  
Non Destructive ◽  
Decay Gamma ◽  
Capture Cross Sections

SummaryAccurate partial gamma-ray production cross sections were determined for the prompt and radioactive product decay gamma rays following cold neutron capture in

THE 51V(n, γ)52V REACTION

1967 ◽  
Vol 45 (8) ◽  
pp. 2683-2694 ◽  
Author(s):  
N. P. Archer ◽  
T. J. Kennett
Keyword(s):  
Gamma Radiation ◽  
Thermal Neutron ◽  
Ground State ◽  
Neutron Capture ◽  
Decay Scheme ◽  
Thermal Neutron Capture ◽  
Separation Energy ◽  
Direct Capture ◽  
Coincidence Measurements

The gamma radiation following thermal neutron capture by vanadium has been studied using a Ge(Li) detector. A separation energy of 7 311 ± 2 keV was determined and the ground-state triplet was observed, confirming levels of 17 and 23 keV. Coincidence measurements were used to assist in the construction of a decay scheme which includes 97% of the total observed intensity. The agreement with (d, p) measurements is very good and permits one to conclude that essentially all of the observed transitions are E1. The lack of any correlation between reduced radiation widths and stripping strengths suggests the absence of direct capture.

A study of the 23Na(n,γ)24Na and 27Al(n,γ)28Al reactions

1969 ◽  
Vol 47 (9) ◽  
pp. 953-961 ◽  
Author(s):  
L. W. Nichol ◽  
A. H. Colenbrander ◽  
T. J. Kennett
Keyword(s):  
Gamma Radiation ◽  
Thermal Neutron ◽  
Gamma Rays ◽  
Neutron Capture ◽  
Decay Scheme ◽  
Thermal Neutron Capture

A study of the gamma radiation following thermal-neutron capture by natural sodium and aluminum has been conducted using a Ge(Li) spectrometer. For sodium, 68 gamma rays were observed and their intensities and energies determined; for aluminum, 85 gamma rays were identified. A decay scheme for aluminum has been proposed from the present measurements. The neutron separation energies were found to be 6960.3 ± 1.5 keV for sodium and 7725.5 ± 1.5 keV for aluminum. The lifetime of the 472-keV level in sodium was measured to be 20.5 ± 0.5 ms using a chopped beam of neutrons.

GAMMA‐RAY SPECTROSCOPY IN WELL LOGGING

Geophysics ◽  
1963 ◽  
Vol 28 (4) ◽  
pp. 617-632 ◽  
Author(s):  
Richard L. Caldwell ◽  
Willett F. Baldwin ◽  
James D. Bargainer ◽  
James E. Berry ◽  
George N. Salaita ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Neutron Capture ◽  
Gamma Ray ◽  
Salt Water ◽  
Pulse Height ◽  
Energy Calibration ◽  
Good Energy Resolution ◽  
Scintillation Crystal ◽  
Natural Gamma ◽  
Good Energy

Thermal neutron capture gamma rays have been observed in boreholes drilled in shales, sandstones, and limestones. A capsuled source of neutrons and a scintillation crystal detector, connected through 5,000 ft of logging cable to a transistorized, multichannel, pulse‐height analyzer, were used. Resolved peaks were identified on the basis of the known energies of expected gamma rays and results obtained in models where conditions of porosity, casing, and fluid were controlled. To properly interpret borehole spectral data a system with good energy resolution and an accurate means of energy calibration are necessary. This is accomplished by using hydrogen and iron to give prominent gamma‐ray peaks at opposite ends of the energy range of interest. On field spectra, identification was made of gamma rays from chlorine, silicon, calcium, hydrogen, and iron. On the basis of chlorine gamma rays, salt water can be differentiated from oil or fresh water. Gamma rays from iron casing are an undesirable background and reduce the sensitivity of the method compared to that possible in an uncased hole. Two examples of natural gamma‐ray spectra show well resolved lines from uranium‐radium and thorium.

scholarly journals Gamma-Ray Lines from Solar Flares

1975 ◽  
Vol 68 ◽  
pp. 363-383 ◽  
Author(s):  
R. Ramaty ◽  
R. E. Lingenfelter
Keyword(s):  
Gamma Rays ◽  
Solar Flares ◽  
Neutron Capture ◽  
Gamma Ray ◽  
Nuclear Reactions ◽  
The Other ◽  
Line Production ◽  
Absolute Intensities ◽  
Flare Region ◽  
Accelerated Particles

We have treated in detail the theory of gamma-ray line production in solar flares. The strongest line, both predicted theoretically and detected observationally at 2.2 MeV, is due to neutron capture by protons in the photosphere. The neutrons are produced in nuclear reactions of flare accelerated particles which also produce positrons and prompt nuclear gamma rays. From the comparison of the observed and calculated intensities of the lines at 4.4 or 6.1 MeV to that of the 2.2 MeV line it is possible to deduce the spectrum of accelerated nuclei in the flare region; and from the absolute intensities of these lines it is possible to obtain the total number of accelerated nuclei at the Sun. The study of the 2.2 MeV line also gives information on the amount of He3 in the photosphere. The study of the line at 0.51 MeV resulting from positron annihilation complements the data obtained from the other lines; in addition it gives information on the temperature and density in the annihilation region and on the anisotropy of the accelerated electron beam which produces continuum gamma rays at energies greater than about 1 MeV.

The scattering of gamma-rays in extended media III. Problems with spherical symmetry

1950 ◽  
Vol 204 (1078) ◽  
pp. 329-338 ◽  
Keyword(s):  
Gamma Radiation ◽  
Compton Scattering ◽  
Gamma Rays ◽  
Spherical Symmetry ◽  
Gamma Ray ◽  
Scattering Medium ◽  
Air Gaps ◽  
Source Dimensions ◽  
Large Source ◽  
Absorbing Materials

Some typical problems of the propagation of gamma-radiation in an extended scattering medium have been solved for pure Compton scattering, which is a good approximation for most materials at gamma-ray energies up to a few MeV. The effects to be expected from air gaps round the source, large source dimensions, and plane absorbing materials are demonstrated.

Gamma-activation analysis of selenium at the electron accelerator “Mikrotron-ST”

2020 ◽  
Vol 6 ◽  
pp. 18-22
Author(s):  
V.I. Tovtin ◽  
◽  
V.N. Kolokoltsev ◽  
N.N. Dogadkin ◽  
E.E. Starostin ◽  
...  
Keyword(s):  
Activation Analysis ◽  
Gamma Radiation ◽  
Gamma Rays ◽  
Electron Accelerator ◽  
Room Temperature ◽  
Gamma Ray ◽  
Polyethylene Capsule ◽  
Mechanical Dispersion ◽  
Quantum Radiation ◽  
Energy Gamma

In this work, an activation analysis of selenium under its irradiation with bremsstrahlung gamma radiation on a cyclic electron accelerator “Microtron-sT” with an energy of 21 MeV is carried out irradiation was performed at room temperature for 1 h, the gamma-ray intensity was ~ 5·1013 γ/s. Irradiation was carried out on two types of state of the samples (Se) in the form of granules of the (osch), weight 5-10 mg, and microparticles (powder) obtained by mechanical dispersion. Samples in the state of microparticles were suspended in distilled water, in separate polyethylene capsule. On each sample, after irradiation with bremsstrahlung gamma radiation, the spectra of quantum radiation of radionuclides were measured. The measurements were carried out repeatedly in order to observe a decrease in the activity of the samples and their energy gamma spectrum. From the results obtained, it can be seen that all radionuclides are formed on selenium nuclei with different mass numbers by reactions: (γ, n), (γ, p), (γ, 2n), (γ, p + n). The half-life of (T1/2) in identified radionuclides is within 3.9 minutes — 119.8 days. The energy of emitted quanta by radionuclides is equal to from 121.1 to 657 keV. The radiation intensity of radionuclide gamma rays is in the range: 0.25-99.0%.

DETERMINATION OF THE ABSORPTION PARAMETERS OF SOME MATERIALS FOR PHOTON ENERGIES WITH NAI (TL) DETECTOR.

2020 ◽  
Vol 9 (8) ◽  
Keyword(s):  
Gamma Radiation ◽  
Layer Thickness ◽  
Attenuation Coefficient ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Mass Attenuation Coefficient ◽  
Linear Attenuation Coefficient ◽  
Absorption Properties ◽  
Specific Parameter

Shielding of gamma radiation primarily involves the interaction of gamma radiation with matter. In this measurements have been made to determine the absorption parameters of Carbon, Copper and lead elemental materials of gamma-rays photons from 22Na, 137Cs and 60Co sources using the NaI (Tl) detector. The attenuation in the intensity of the beam will be determined for each varying thickness of absorber materials. Absorption properties were interpreted by means of the linear attenuation coefficient µ, mass attenuation coefficient µm , half-value layer thickness and ten value layer thickness. Among these the mass absorption coefficients is the most specific parameter because it can be specified only by gamma ray energy.

scholarly journals Improved STEREO simulation with a new gamma ray spectrum of excited gadolinium isotopes using FIFRELIN

2019 ◽  
Vol 55 (10) ◽  
Author(s):  
H. Almazán ◽  
L. Bernard ◽  
A. Blanchet ◽  
A. Bonhomme ◽  
C. Buck ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Cross Sections ◽  
Neutron Capture ◽  
Gamma Ray ◽  
Detection Efficiency ◽  
Liquid Scintillator ◽  
Calibration Source ◽  
Active Volume ◽  
Capture Event ◽  
Excited Nuclei

Abstract. The STEREO experiment measures the electron antineutrino spectrum emitted in a research reactor using the inverse beta decay reaction on H nuclei in a gadolinium loaded liquid scintillator. The detection is based on a signal coincidence of a prompt positron and a delayed neutron capture event. The simulated response of the neutron capture on gadolinium is crucial for the comparison with data, in particular in the case of the detection efficiency. Among all stable isotopes, 155Gd and 157Gd have the highest cross sections for thermal neutron capture. The excited nuclei after the neutron capture emit gamma rays with a total energy of about 8MeV. The complex level schemes of 156Gd and 158Gd are a challenge for the modeling and prediction of the deexcitation spectrum, especially for compact detectors where gamma rays can escape the active volume. With a new description of the Gd (n,$ \gamma$γ) cascades obtained using the FIFRELIN code, the agreement between simulation and measurements with a neutron calibration source was significantly improved in the STEREO experiment. A database of ten millions of deexcitation cascades for each isotope has been generated and is now available for the user.

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