Search for 511 keV electron-positron annihilation radiation from mildly active galaxies using the HEAO 3 gamma-ray spectrometer

1984 ◽  
Vol 281 ◽  
pp. 566 ◽  
Author(s):  
A. P. Marscher ◽  
K. Brecher ◽  
W. A. Wheaton ◽  
J. C. Ling ◽  
W. A. Mahoney ◽  
...  
Keyword(s):  
Positron Annihilation ◽  
Gamma Ray ◽  
Active Galaxies ◽  
Annihilation Radiation ◽  
Gamma Ray Spectrometer ◽  
Electron Positron Annihilation ◽  
Electron Positron

INTEGRAL results on the electron-positron annihilation radiation and X-ray & Gamma-ray diffuse emission of the Milky Way

2020 ◽  
Vol 90 ◽  
pp. 101548 ◽  
Author(s):  
Eugene Churazov ◽  
Laurent Bouchet ◽  
Pierre Jean ◽  
Elisabeth Jourdain ◽  
Jürgen Knödlseder ◽  
...  
Keyword(s):  
Positron Annihilation ◽  
Milky Way ◽  
Gamma Ray ◽  
Annihilation Radiation ◽  
Diffuse Emission ◽  
X Ray ◽  
Electron Positron Annihilation ◽  
Electron Positron

scholarly journals Calculation of the Doppler broadening of the electron-positron annihilation radiation in defect-free bulk materials

2000 ◽  
Vol 61 (15) ◽  
pp. 10092-10099 ◽  
Author(s):  
V. J. Ghosh ◽  
M. Alatalo ◽  
P. Asoka-Kumar ◽  
B. Nielsen ◽  
K. G. Lynn ◽  
...  
Keyword(s):  
Positron Annihilation ◽  
Annihilation Radiation ◽  
Doppler Broadening ◽  
Bulk Materials ◽  
Electron Positron Annihilation ◽  
Electron Positron

Doppler broadening measurements of the electron-positron annihilation radiation in nanocrystalline ZrO2

2005 ◽  
Vol 40 (19) ◽  
pp. 5265-5268 ◽  
Author(s):  
M. Chakrabarti ◽  
D. Bhowmick ◽  
A. Sarkar ◽  
S. Chattopadhyay ◽  
S. Dechoudhury ◽  
...  
Keyword(s):  
Positron Annihilation ◽  
Annihilation Radiation ◽  
Doppler Broadening ◽  
Electron Positron Annihilation ◽  
Electron Positron

scholarly journals Is this the possible explanation to the unpredictability of the direction of of gamma ray emission during electron-positron annihilation ?

2021 ◽  
Author(s):  
Jayaram as
Keyword(s):  
Quantum Mechanics ◽  
Positron Annihilation ◽  
Alternative Explanation ◽  
Gamma Ray ◽  
Classical Mechanics ◽  
Annihilation Process ◽  
Electron Positron Annihilation ◽  
Electron Positron ◽  
Gamma Ray Emission ◽  
Electron Positron Pair

This paper shows the various parameters to be considered, duringelectron - positron annihilation. Many of the theories suggest that directionof gamma ray emission cannot be predicted. This is normally justifiedby using quantum mechanics. This paper gives an alternative explanation tounpredictability of gamma ray direction. This explanation does not require thelogic of quantum mechanics. It requires modification of classical mechanics toaccount of the forces between colliding particles.The logic of this paper is thatin case of pair production involving gamma ray and electron- positron pair, theclassical mechanics calculation itself shows perfect conservation of directionand magnitude of momentum. There, a little recoiling of the nucleus is observedfor conserving momentum. Hence it must be possible to use classicalmechanics for the process of electron- positron annihilation process also.

scholarly journals Measuring electron-positron annihilation radiation from laser plasma interactions

2012 ◽  
Vol 83 (10) ◽  
pp. 10E113 ◽  
Author(s):  
Hui Chen ◽  
R. Tommasini ◽  
J. Seely ◽  
C. I. Szabo ◽  
U. Feldman ◽  
...  
Keyword(s):  
Positron Annihilation ◽  
Laser Plasma ◽  
Annihilation Radiation ◽  
Plasma Interactions ◽  
Laser Plasma Interactions ◽  
Electron Positron Annihilation ◽  
Electron Positron

scholarly journals INTEGRALSPI Limits on Electron‐Positron Annihilation Radiation from the Galactic Plane

2005 ◽  
Vol 621 (1) ◽  
pp. 296-300 ◽  
Author(s):  
B. J. Teegarden ◽  
K. Watanabe ◽  
P. Jean ◽  
J. Knodlseder ◽  
V. Lonjou ◽  
...  
Keyword(s):  
Positron Annihilation ◽  
Galactic Plane ◽  
Annihilation Radiation ◽  
Electron Positron Annihilation ◽  
Electron Positron

scholarly journals Positron Annihilation Radiation from the 1991 November 15 Flare

1994 ◽  
Vol 142 ◽  
pp. 701-705
Author(s):  
K. Kawabata ◽  
M. Yoshimori ◽  
K. Suga ◽  
K. Morimoto ◽  
T. Hiraoka ◽  
...  
Keyword(s):  
Positron Annihilation ◽  
Gamma Ray ◽  
Nuclear Reactions ◽  
Time Profile ◽  
Time Interval ◽  
Prompt Gamma ◽  
Annihilation Radiation ◽  
X Rays ◽  
Gamma Ray Spectrometer ◽  
Flare Loops

AbstractThe gamma-ray spectrometer on Yohkoh has detected the positron annihilation line at 511 keV produced during the 1991 November 15 flare (X1.0/3B). The 511 keV line fluence, integrated over the time interval of 22:37:50-22:38:14 UT, is (6.7 ± 2.2) photons cm−2 . The time profile of 511 keV line exhibited long decay time compared with the electron bremsstrahlung and prompt gamma-ray line components. From the analysis of time profile of the 511 keV line, we come to the following conclusions: (1) the main source of positrons is deexcitation of 16O *6.052 by e+ – e- pair emisson. (2) β+ −emitting nuclei of 31S, 29P, 27Si, 26mAl, 25Al,23Mg, 19Ne, and 21Na are also important sources of positrons in the decay phase. (3) The density of the positron annihilation region in the photosphere is 1016 cm−3 . (4) Most likely interpretation of the time profile is that at least 50% of positrons annihilate in coronal flare loops with a density of 1012−1013 cm−3 and with a temperature of 106 −3 × 106 K.Subject headings: nuclear reactions, nucleosynthesis, abundances — Sun: flares — Sun: X-rays, gamma-rays

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