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The so-called long-duration gamma-ray bursts produce a total energy output of about 10 44 joules (as much energy as the Sun will produce in its entire life-time) but in a period of only 20 to 40 seconds. Gamma rays are approximately 50% of the total energy output.
If the lost recoil energy is small compared with the energy linewidth of the nuclear transition, then the gamma-ray energy still corresponds to the energy of the nuclear transition and the gamma ray can be absorbed by a second atom of the same type as the first. This emission and subsequent absorption is called resonant fluorescence. Additional ...
A gamma ray cross section is a measure of the probability that a gamma ray interacts with matter. The total cross section of gamma ray interactions is composed of several independent processes: photoelectric effect, Compton (incoherent) scattering, electron-positron pair production in the nucleus field and electron-positron pair production in the electron field (triplet production).
Gamma radiation detected in an isopropanol cloud chamber. Gamma (γ) radiation consists of photons with a wavelength less than 3 × 10 −11 m (greater than 10 19 Hz and 41.4 keV). [4] Gamma radiation emission is a nuclear process that occurs to rid an unstable nucleus of excess energy after most nuclear reactions. Both alpha and beta particles ...
The incoming gamma ray effectively knocks one or more neutrons, protons, or an alpha particle out of the nucleus. [1] The reactions are called (γ,n), (γ,p), and (γ,α), respectively. Photodisintegration is endothermic (energy absorbing) for atomic nuclei lighter than iron and sometimes exothermic (energy releasing) for atomic nuclei heavier ...
In particular, a photon with a wavelength of less than 91 nanometers is energetic enough to completely ionize neutral hydrogen and is absorbed with almost 100% probability even through relatively thin gas clouds. (At much shorter wavelengths the probability of absorption begins to drop again, which is why X-ray afterglows are still detectable.)
The means by which gamma-ray bursts convert energy into radiation remains poorly understood, and as of 2010 there was still no generally accepted model for how this process occurs. [132] Any successful model of GRB emission must explain the physical process for generating gamma-ray emission that matches the observed diversity of light curves ...
Gamma rays are photons, whose absorption cannot be described by LET. When a gamma quantum passes through matter, it may be absorbed in a single process (photoelectric effect, Compton effect or pair production), or it continues unchanged on its path. (Only in the case of the Compton effect, another gamma quantum of lower energy proceeds).