The calibration methods for in-situ gamma spectrometry systems used CIEMAT include semiempirical approaches using point sources, pure mathematical calibrations using the ISOCS software and a stripping method developed at CIEMAT. The two first procedures give information about the activity concentration in the soil, and the third method provides distributions of dosimetric quantities as a functi...

The Milky Way has been estabished to emit gamma rays. These gamma rays are presumably dominated by decays of neutral pions, although inverse Compton scatterings and bremsstrahlung also contribute. It is plausible that other galaxies can be diffuse sources of gamma rays in a similar manner. Starburst galaxies are particularly interesting to study as they are expected to have much higher cosmic-r...

Gamma has shown to be a powerful and expressive formalism that allows the basic computation of an algorithm to be expressed with a minimum of control. In a second stage of the design process, the highly nondeterministic behaviour of Gamma can be exploited to impose additional control using a separate coordination language. Separating computation from coordination facilitates correctness proofs ...

We report high-energy spectral data of the prompt emission of GRB970228 and its X–ray afterglow. We establish that the nature of the X–ray afterglow emission is non-thermal and similar to the later portion of GRB970228. Our data can be used to discriminate different emission models of GRB afterglows. While cooling of excited compact objects can be ruled out, fireball models are constrained in t...

We present a proposal for testing the prediction of non-equilibrium quantum field theory below the Schwinger limit. The proposed experiments should be able to detect a measurable number of gamma rays resulting from the annihilation of pairs in the focal spot of two opposing high intensity laser beams. We discuss the dependence of the expected number of gamma rays with the laser parameters and c...

We investigate the internal consistency of the halo dark matter model which has been proposed by de Boer et al. to explain the excess of diffuse galactic gamma rays observed by the EGRET experiment. Any model based on dark matter annihilation into quark jets, such as the supersymmetric model proposed by de Boer et al., inevitably also predicts a primary flux of antiprotons from the same jets. S...

It is known that the soft tail of the gamma-ray bursts’ spectra show excesses from the exact power-law dependence. In this article we show that this departure can be detected in the peak flux ratios of different BATSE DISCSC energy channels. This effect allows to estimate the redshift of the bright long gamma-ray bursts in the BATSE Catalog. A verification of these redshifts is obtained for the...

GRB990123 was a long complex gamma-ray burst with an optical transient that started early within the gamma-ray phase (Akerlof et al. 1999a, Akerlof et al. 1999b). The peak and power law decay of the early optical emission strongly indicates the presence of a decelerating relativistic shell during that phase. Prior to this burst, it was not known if the shell decelerated during the burst, so an ...

The exposure rate due to the gamma-ray natural background in some representative areas of the Country was studied by means, of a portable high-pressure iQuization ch."mlber. In ali limited area such study was integrated by a survey 0n the quality of ba.ckgrowlC! radiation, carried out by gamma spectrometric measurements. . The spectrometric study permitte<;l the determination of the contrilbuti...

Observational signatures of existence of antimatter objects in the Galaxy are discussed. We focus on point-like sources of gamma radiation, diffuse galactic gamma ray background and anti-nuclei in cosmic rays.