Gamma rays in the energy range above ∼ 30 Gev have not been well sampled from space to date, given their low fluxes, and ground-based techniques have only recently matured to the point where efficient observations are feasible. As outlined previously, cosmic gamma rays are absorbed in the ...
Examples: rays of chastity, 1634; of comfort, 1781; of divinity, 1674; of genius, 1856; of gold, 1729; of hope, 1838; of horsemen, 1542; of truth, 1732. Dictionary of Collective Nouns and Group Terms. Copyright 2008 The Gale Group, Inc. All rights reserved. rayPast participle: rayed...
in the patient. The first part of the gamma camera is a collimator. It absorbs γ rays that do not travel parallel to the plates, improving image resolution. The γ rays that pass through the collimator strike a scintillation crystal. This crystal, often made of sodium iodide with trace ...
The schematic views of the real NaI(Tl) scintillation detector and the fake detector are illustrated in Fig. 1. However, there is a little difference between interaction of gamma-rays with NaI(Tl) and NaCl in simulations (Fig. 2), which can be ignored. Also, NaCl can be a suitable ...
high-energy gamma rays in these otherwise-quiet regions of space. And if the bursts came from galaxies millions or billions of light-years away, then they must be extremely powerful to be observable at such large distances; indeed they had to be the among the biggest explosions in the ...
rays, Sco X-1 [49]. An excellent summary of the early cosmic ray research from its beginning to about 1960 is contained in the text book “Cosmic Rays” [130]. The real history of gamma-ray astronomy started with predictions in the 1950s: Hayakawa predicted the diffuse galactic gamma-...
placed 18-20 mm lateral to the midline, 35 mm posterior to the tip of the frontal pole and at a depth of 20-22 mm from the brain surface using a stereotaxic micromanipulator. Electrode depths and placements were calculated with reference to X-rays, as previously described [42]. They were...
Gamma raysare produced in copious quantities in theupper atmosphereof the Earth as a consequence of cosmic-ray interactions. Balloon experiments rely typically on the “growth curve” technique to estimate the contribution of atmosphericgamma raysto the observed event count rate. In this method, the...
The annihilation cross section is then smaller than the bounds from continuum gamma rays in Fermi-LAT. Using FeynArts [70], we estimate that for the benchmark point with the stable 5-plet (left part of Table 1), the annihilation cross section to W+W− is 〈σvrel〉=2.0×10−26cm3...
gamma-rays; emission: non-thermal; variability; origin: jet; origin: black hole1. Introduction The last decade has seen tremendous experimental progress in gamma-ray astronomy much beyond simple source detection (e.g., see [1,2,3] for a review). In many cases, detailed spectral and timing...