Gamma rays produced in the 209Bi(n, n′γ) reaction

1984 ◽  
Vol 62 (10) ◽  
pp. 948-962 ◽  
Author(s):  
W. V. Prestwich ◽  
T. J. Kennett ◽  
J. S. Tsai
Keyword(s):  
High Resolution ◽  
Gamma Rays ◽  
Energy Region ◽  
Weak Coupling ◽  
Decay Scheme ◽  
High Energy ◽  
High Energy Region ◽  
Γ Rays ◽  
Γ Ray ◽  
Resolution Study

A high-resolution study of the γ-ray spectrum induced by the inelastic scattering of reactor produced neutrons has been conducted. The γ rays observed have been assigned in a decay scheme involving 134 levels extending in excitation energy to 6 MeV. The results are discussed within the context of previously identified weak coupling configurations, and possible discrepancies are indicated. Levels in the high-energy region are also compared with recently reported photoexcitation studies.

Gamma rays and high-energy neutrons in the atmosphere

1968 ◽  
Vol 46 (10) ◽  
pp. S1030-S1033 ◽  
Author(s):  
M. V. K. Apparao ◽  
R. R. Daniel ◽  
George Joseph ◽  
G. S. Gokhale ◽  
P. J. Lavakare ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Counting Rate ◽  
Plastic Scintillator ◽  
Pulse Height ◽  
Growth Curves ◽  
High Energy ◽  
Cutoff Rigidity ◽  
Energy Formula ◽  
Γ Rays ◽  
Γ Ray

In continuation of our earlier experiments studying the emission of solar neutrons, we have now developed detector systems which respond to γ rays of energy 1–5 MeV and neutrons of energy [Formula: see text]. The two detectors are almost identical. Each consists of a CsI (Na) crystal (B) of diameter 3.8 cm, completely enclosed in a tapered cylinder of plastic scintillator (A) operated in anticoincidence; the crystals have thicknesses of 2.4 and 1.2 cm respectively. A balloon carrying these detectors was flown on March 16, 1967 over Hyderabad, India (vertical cutoff rigidity 16.9 GV) and floated at a ceiling altitude of 6.0 mb for 1 hour. In addition to γ-ray and neutron events (AB), events A and AB were also continuously monitored throughout the flight. Pulses corresponding to 1–5 MeV in the 2.4-cm crystal (γ rays) and 6–40 MeV in the 1.2-cm crystal (high-energy neutrons) were analyzed by a 64-channel pulse-height analyzer. On the basis of the pulse-height distributions and γ-ray efficiencies in the two crystals, we attribute events of 1–5 MeV energy from the thicker crystal to γ rays and those > 10 MeV in energy from the thinner one to stars produced by high-energy neutrons [Formula: see text] in the crystal. Atmospheric growth curves for γ rays and neutrons have been obtained; these growth curves as well as those for events A and AB show the normal features of the Pfotzer maximum, steady decreases up to the ceiling altitude, and a constant counting rate at ceiling. The atmospheric counting rates at ceiling altitude give for γ rays of energy 1–5 MeV a flux of ~1 photon per cm2 s and for neutrons of energy [Formula: see text] a flux of ~0.1 neutron per cm2 s. No evidence for a solar component in either channel was found.

scholarly journals A search for high-energy γ-rays from pulsars

1970 ◽  
Vol 37 ◽  
pp. 192-195 ◽  
Author(s):  
G. G. Fazio ◽  
D. R. Hearn ◽  
H. F. Helmken ◽  
G. H. Rieke ◽  
T. C. Weekes
Keyword(s):  
Energy Region ◽  
Energetic Particle ◽  
Crab Nebula ◽  
High Energy ◽  
Γ Radiation ◽  
Γ Rays ◽  
Γ Ray ◽  
Cerenkov Light

The 10-m optical reflector at Mt. Hopkins, Ariz., was used to search for cosmic γ radiation from pulsars by detection of atmospheric Čerenkov light generated by energetic particle showers. In the energy region of 1011–1012 eV, no evidence of pulsed γ-ray emission was found from either NP0532 (Crab Nebula) or CP1133.

scholarly journals VHE GAMMA-RAYS FROM GALACTIC X-RAY BINARY SYSTEMS

2008 ◽  
Vol 17 (10) ◽  
pp. 1849-1858 ◽  
Author(s):  
J. M. PAREDES
Keyword(s):  
Gamma Rays ◽  
Binary Systems ◽  
High Energy ◽  
X Ray ◽  
Very High Energy ◽  
Γ Rays ◽  
Γ Ray ◽  
Tev Gamma Rays ◽  
X Ray Binaries ◽  
Very High

The detection of TeV gamma-rays from LS 5039 and the binary pulsar PSR B1259–63 by HESS, and from LS I +61 303 and the stellar-mass black hole Cygnus X-1 by MAGIC, provides clear evidence of very efficient acceleration of particles to multi-TeV energies in X-ray binaries. These observations demonstrate the richness of nonthermal phenomena in compact galactic objects containing relativistic outflows or winds produced near black holes and neutron stars. I review here some of the main observational results on very high energy (VHE) γ-ray emission from X-ray binaries, as well as some of the proposed scenarios to explain the production of VHE γ-rays. I put special emphasis on the flare TeV emission, suggesting that the flaring activity might be a common phenomena in X-ray binaries.

NEUTRON CAPTURE GAMMA RAYS FROM FLUORINE, MAGNESIUM, GALLIUM, BROMINE, AND HAFNIUM

1957 ◽  
Vol 35 (12) ◽  
pp. 1361-1379 ◽  
Author(s):  
P. J. Campion ◽  
G. A. Bartholomew
Keyword(s):  
Energy Range ◽  
Gamma Rays ◽  
Ground State ◽  
Neutron Capture ◽  
State Transition ◽  
High Energy ◽  
The Other ◽  
Ground State Transition ◽  
Γ Rays ◽  
Γ Ray

The neutron capture γ-ray spectra of fluorine, magnesium, gallium, bromine, and hafnium have been studied in the energy range above 3 Mev. In fluorine four γ-rays and in magnesium 12 γ-rays have been detected in addition to those previously observed. Most of these new radiations can be assigned to the known level schemes of the product nuclei. The spectrum obtained for each of the other elements is complex with only a few of the high energy γ-rays resolved, and in each case the γ-ray of highest energy is very weak and difficult to distinguish from the background. The most energetic gallium γ-ray at 7.73 ± 0.02 Mev. may be emitted in the direct ground state transition in Ga70 while the 7.879 ± 0.013 Mev. γ-ray from bromine probably corresponds to the ground state transition in Br80. In hafnium none of the observed γ-rays can be identified with a ground state transition in any of the isotopes.

HIGH-RESOLUTION STUDIES OF GAMMA-RAY SPECTRA USING LITHIUM-DRIFT GERMANIUM GAMMA-RAY SPECTROMETERS

1964 ◽  
Vol 42 (11) ◽  
pp. 2286-2331 ◽  
Author(s):  
G. T. Ewan ◽  
A. J. Tavendale
Keyword(s):  
High Resolution ◽  
Gamma Ray ◽  
High Energy ◽  
Factors Affecting ◽  
Γ Rays ◽  
Γ Ray

This paper describes the use of germanium lithium-drift p-i-n diodes as high-resolution γ-ray spectrometers. With these spectrometers we have obtained γ-ray resolutions of 2.05 keV at 122 keV, 4.0 keV at 1333 keV, and 5.5 keV at 2614 keV. Using the detectors as pair spectrometers for high-energy γ rays, we have obtained a resolution of 9.8 keV on a 7.6-MeV γ ray. The factors affecting the resolution of the detectors are discussed. Fano factors of ~0.4 have been observed. Efficiency curves are given for a 2.5 cm2 × 3.5 mm detector and for a 5 cm2 × 8 mm detector.The detectors have been used to make high-resolution studies of the complex γ-ray spectra from sources of 131Cs, 161Pm, 153Gd, 156Eu, 159Gd, 177Yb, and 226Ra. Results are reported for the energies and intensities of the γ rays observed in these studies.

scholarly journals Analysis of Shielding Performance of Radiation-Shielding Materials According to Particle Size and Clustering Effects

2021 ◽  
Vol 11 (9) ◽  
pp. 4010
Author(s):  
Seon-Chil Kim
Keyword(s):  
Particle Size ◽  
Polymer Material ◽  
Energy Region ◽  
High Energy ◽  
Radiation Shielding ◽  
High Energy Region ◽  
Particle Structure ◽  
Effect Of Particle Size ◽  
Extensive Body ◽  
Shielding Material

In the field of medical radiation shielding, there is an extensive body of research on process technologies for ecofriendly shielding materials that could replace lead. In particular, the particle size and arrangement of the shielding material when blended with a polymer material affect shielding performance. In this study, we observed how the particle size of the shielding material affects shielding performance. Performance and particle structure were observed for every shielding sheet, which were fabricated by mixing microparticles and nanoparticles with a polymer material using the same process. We observed that the smaller the particle size was, the higher both the clustering and shielding effects in the high-energy region. Thus, shielding performance can be improved. In the low-dose region, the effect of particle size on shielding performance was insignificant. Moreover, the shielding sheet in which nanoparticles and microsized particles were mixed showed similar performance to that of the shielding sheet containing only microsized particles. Findings indicate that, when fabricating a shielding sheet using a polymer material, the smaller the particles in the high-energy region are, the better the shielding performance is. However, in the low-energy region, the effect of the particles is insignificant.

scholarly journals π--PInteraction in High Energy Region

1957 ◽  
Vol 18 (3) ◽  
pp. 264-268 ◽  
Author(s):  
Daisuke Ito ◽  
Tetsuro Kobayashi ◽  
Miwae Yamazaki ◽  
Shigeo Minami
Keyword(s):  
Energy Region ◽  
High Energy ◽  
High Energy Region

scholarly journals Molecular Clouds Observed by the EGRET Gamma-Ray Telescope

1997 ◽  
Vol 170 ◽  
pp. 22-24 ◽  
Author(s):  
Seth. W. Digel ◽  
Stanley D. Hunter ◽  
Reshmi Mukherjee ◽  
Eugéne J. de Geus ◽  
Isabelle A. Grenier ◽  
...  
Keyword(s):  
Molecular Mass ◽  
Molecular Clouds ◽  
Gamma Ray ◽  
Angular Resolution ◽  
Cosmic Ray ◽  
High Energy ◽  
Background Rejection ◽  
Γ Rays ◽  
Γ Ray ◽  
Production Mechanisms

EGRET, the high-energy γ-ray telescope on the Compton Gamma-Ray Observatory, has the sensitivity, angular resolution, and background rejection necessary to study diffuse γ-ray emission from the interstellar medium (ISM). High-energy γ rays produced in cosmic-ray (CR) interactions in the ISM can be used to determine the CR density and calibrate the CO line as a tracer of molecular mass. Dominant production mechanisms for γ rays of energies ∼30 MeV–30 GeV are the decay of pions produced in collisions of CR protons with ambient matter and Bremsstrahlung scattering of CR electrons.

High resolution study of the autoionizing states of He in their exchange interference energy region

2018 ◽  
Vol 225 ◽  
pp. 10-15 ◽  
Author(s):  
Béla Paripás ◽  
Jozo Jureta ◽  
Béla Palásthy ◽  
Bratislav Marinković ◽  
Gábor Pszota
Keyword(s):  
High Resolution ◽  
Energy Region ◽  
Resolution Study ◽  
Autoionizing States
Sign in / Sign up

Export Citation Format

Share Document