scholarly journals IRRADIATION OF CHLOROFORM–WATER SYSTEMS WITH CO60 GAMMA-RAYS AND BETATRON X RAYS

1954 ◽  
Vol 32 (5) ◽  
pp. 522-531 ◽  
Author(s):  
R. W. Hummel ◽  
A. B. Van Cleave ◽  
J. W. T. Spinks
Keyword(s):  
Free Radical ◽  
Radiation Dose ◽  
Gamma Rays ◽  
High Energy ◽  
Water Systems ◽  
Specific Yield ◽  
Average Lifetime ◽  
Square Root ◽  
X Rays ◽  
Co60 Gamma

The production of acid from two commercial brands of chloroform, on exposure to Co60 gamma-rays and high energy X rays from a betatron, has been measured. Inhibitor-free chloroform liberates acid in amounts varying linearly with the radiation dose. The specific yield, in micromoles of acid produced per liter of chloroform per kiloroentgen, varies inversely as the square root of the dose rate. The specific yields are slightly less for betatron radiations, compared with Co60 gamma-rays. The average lifetime of the free radical chains is about one second.

IRRADIATION OF ONE MOLAR AQUEOUS CHLORAL HYDRATE SOLUTION WITH Co60-GAMMA-RAYS AND BETATRON X RAYS

1953 ◽  
Vol 31 (12) ◽  
pp. 1164-1172 ◽  
Author(s):  
G. R. Freeman ◽  
A. B. Van Cleave ◽  
J. W. T. Spinks
Keyword(s):  
Gamma Rays ◽  
Chloral Hydrate ◽  
Specific Yield ◽  
Square Root ◽  
X Rays ◽  
Chain Reaction ◽  
Peak Energy ◽  
Γ Rays ◽  
A Chain ◽  
Co60 Gamma

The production of acid by irradiation of 1 M chloral hydrate solutions is proportional to the dose at a given dose rate. The specific yield is the same for Co60 γ-rays as for 23 Mev. peak energy X rays and is a linear function of the inverse of the square root of the close rate. The reaction is apparently a chain reaction.

IRRADIATION OF AQUEOUS CHLORAL HYDRATE SOLUTIONS WITH Co60 GAMMA-RAYS: AVERAGE LIFETIME OF THE FREE RADICAL CHAINS

1954 ◽  
Vol 32 (3) ◽  
pp. 322-326 ◽  
Author(s):  
G. R. Freeman ◽  
A. B. Van Cleave ◽  
J. W. T. Spinks
Keyword(s):  
Free Radical ◽  
Hydrochloric Acid ◽  
Gamma Rays ◽  
Chloral Hydrate ◽  
Average Lifetime ◽  
X Rays ◽  
Chain Reaction ◽  
Radical Chain ◽  
A Chain ◽  
Co60 Gamma

When aqueous one molar chloral hydrate solutions are irradiated with X rays or gamma-rays, hydrochloric acid is produced. The reaction appears to be a chain reaction. The average free radical chain lifetime, as determined using a rotating sector, is approximately 0.1 sec.

scholarly journals Physical Constraints on Models of Gamma-Ray Bursters

1986 ◽  
Vol 89 ◽  
pp. 305-321
Author(s):  
Richard I. Epstein
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
High Energy ◽  
X Rays ◽  
Burst Source ◽  
Gamma Ray Burst ◽  
Physical Constraints ◽  
Low Energies ◽  
Energy Gamma ◽  
Photon Interactions

AbstractThe power per logarithmic bandwidth in gamma-ray burst spectra generally increases rapidly with energy through the x-ray range and does not cut off sharply above a few MeV. This spectral form indicates that a very small fraction of the energy from a gamma-ray burst source is emitted at low energies or is reprocessed into x-rays and that the high-energy gamma rays are not destroyed by photon-photon interactions. The implications are that the emission mechanism for the gamma-ray bursts is not synchrotron radiation from electrons that lose most of their energy before being re-accelerated and that either the regions from which the gamma rays are emitted are large compared to the size of a neutron star or the emission is collimated and beamed away from the stellar surface.

scholarly journals The Flare of 1989 September 9, 09:09 UT: Does Coronal Loop Collision Initiate Efficient Gamma-Ray Emission?

1994 ◽  
Vol 142 ◽  
pp. 707-711
Author(s):  
H. Aurass ◽  
A. Hofmann ◽  
E. Rieger
Keyword(s):  
Current Sheet ◽  
Gamma Rays ◽  
Coronal Loop ◽  
Gamma Ray ◽  
High Energy ◽  
X Rays ◽  
Subject Headings ◽  
Γ Ray ◽  
Gamma Ray Emission ◽  
Magnetogram Data

AbstractVector magnetogram data and Hα pictures together with data published by Chupp et al. lead us to conjecture that in the presented case a contact between the rising two-ribbon flare current sheet and a coronal loop connecting two nearby plage regions initiates efficient high-energy γ-ray emission.Subject headings: Sun: corona — Sun: flares — Sun: X-rays, gamma rays

The quality factor of x-rays/gamma rays as one is realistic?

2012 ◽  
Vol 11 (3) ◽  
pp. 195-197 ◽  
Author(s):  
Syed F. Akber
Keyword(s):  
Radiation Dose ◽  
Energy Range ◽  
Quality Factor ◽  
Gamma Rays ◽  
Specific Energy ◽  
Biological Systems ◽  
X Rays ◽  
Radiation Quality ◽  
Cell Cycles ◽  
The Mean

AbstractThe quality factor for x-rays, gamma rays and electrons assigned as one need to be revised. It is observed that as the energy decreases, mean lethal radiation dose (Do)decreases as well and become more potent. It is therefore proposed that radiation quality in biological systems should be assessed in the mitotic phase of the cell cycles. Furthermore, based on the mean lethal radiation dose within specific energy range, an appropriate quality factor of x-rays, gamma rays and electrons should be assigned.

Fricke dosimetry: the difference betweenG(Fe3+) for60Co gamma-rays and high-energy x-rays

1999 ◽  
Vol 44 (7) ◽  
pp. 1609-1624 ◽  
Author(s):  
N V Klassen ◽  
K R Shortt ◽  
J Seuntjens ◽  
C K Ross
Keyword(s):  
Gamma Rays ◽  
High Energy ◽  
X Rays ◽  
The Difference

scholarly journals Gamma-Ray Precursors of Solar Flares

1994 ◽  
Vol 142 ◽  
pp. 645-648
Author(s):  
E. Rieger
Keyword(s):  
Spatial Resolution ◽  
Gamma Rays ◽  
Solar Flares ◽  
Gamma Ray ◽  
High Energy ◽  
X Rays ◽  
High Energy Gamma ◽  
Gamma Ray Spectrometer ◽  
Energy Gamma ◽  
Negligible Contribution

AbstractBursts have been observed by the gamma-ray spectrometer on SMM at medium- and high-energy gamma-rays that precede the flare maximum. The negligible contribution of nuclear lines in the spectra of these events and their impulsive appearance suggests that they are hard-electron-dominated events superposed on the flares. Spatial resolution at gamma-ray energies will be necessary to decide whether this kind of bursts is cospatial with the flares or whether they occur in the flares’ vicinity.Subject headings: Sun: flares — Sun: X-rays, gamma rays

scholarly journals Centaurus A at Hard X-Rays and Soft Gamma-Rays

2010 ◽  
Vol 27 (4) ◽  
pp. 431-438 ◽  
Author(s):  
H. Steinle
Keyword(s):  
Energy Range ◽  
Spatial Resolution ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Spectral Energy Distribution ◽  
High Energy ◽  
Spectral Energy ◽  
X Rays ◽  
Satellite Mission ◽  
X Ray

AbstractCen A, at a distance of less than 4 Mpc, is the nearest radio-loud AGN. Its emission is detected from radio to very-high energy gamma-rays. Despite the fact that Cen A is one of the best studied extragalactic objects the origin of its hard X-ray and soft gamma-ray emission (100 keV <E< 50 MeV) is still uncertain. Observations with high spatial resolution in the adjacent soft X-ray and hard gamma-ray regimes suggest that several distinct components such as a Seyfert-like nucleus, relativistic jets, and even luminous X-ray binaries within Cen A may contribute to the total emission in the MeV regime that has been detected with low spatial resolution. As the Spectral Energy Distribution of Cen A has its second maximum around 1 MeV, this energy range plays an important role in modeling the emission of (this) AGN. As there will be no satellite mission in the near future that will cover this energies with higher spatial resolution and better sensitivity, an overview of all existing hard X-ray and soft gamma-ray measurements of Cen A is presented here defining the present knowledge on Cen A in the MeV energy range.

scholarly journals VERY HIGH-ENERGY NEUTRINOS FROM SLOWLY DECAYING, MASSIVE DARK MATTER AS A SOURCE OF EXPLOSIVE ENERGY FOR GAMMA-RAY BURSTS

2003 ◽  
Vol 18 (07) ◽  
pp. 477-489
Author(s):  
SAUL BARSHAY ◽  
GEORG KREYERHOFF
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
Dense Matter ◽  
High Energy ◽  
Wide Distribution ◽  
Gamma Ray Bursts ◽  
Moderate Degree ◽  
X Rays ◽  
Very High Energy ◽  
Total Energies

We consider a speculative model for gamma-ray bursts (GRB), which predicts that the total kinetic energy in the ejected matter is less than the total energy in the gamma rays. There is also secondary energy in X-rays, which are emitted contemporaneously with the gamma rays. The model suggests that bremsstrahlung and Compton up-scattering by very energetic electrons, are important processes for producing the observed burst radiation. The dynamics naturally allows for the possibility of a moderate degree of beaming of matter and radiation in some gamma-ray bursts. GRB are predicted to have an intrinsically wide distribution in total energies, in particular, on the low side. They are predicted to occur at large redshifts, z ~ 8, in local regions of dense matter.

scholarly journals Hot Accretion Disks and the High Energy Background

1983 ◽  
Vol 104 ◽  
pp. 345-346
Author(s):  
M. Kafatos ◽  
Jean A. Eilek
Keyword(s):  
Active Galactic Nuclei ◽  
Accretion Disks ◽  
Spectral Range ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Galactic Nuclei ◽  
Seyfert Galaxies ◽  
High Energy ◽  
X Rays ◽  
X Ray

The origin of the high energy (X-ray and gamma-ray) background may be attributed to discrete sources, which are usually thought to be active galactic nuclei (AGN) (cf. Rothschild et al. 1982, Bignami et al. 1979). At X-rays a lot of information has been obtained with HEAO-1 in the spectral range 2–165 keV. At gamma-rays the background has been estimated from the Apollo 15 and 16 (Trombka et al. 1977) and SAS-2 (Bignami et al. 1979) observations. A summary of some of the observations (Rothschild et al. 1982) is shown in Figure 1. The contribution of AGN to the diffuse high energy background is uncertain at X-rays although it is generally estimated to be in the 20–30% range (Rothschild et al. 1982). At gamma-rays, in the range 1–150 MeV, AGN (specifically Seyfert galaxies) could account for all the emission.

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