Generation of Long-Lived Isomeric States via Bremsstrahlung Irradiation

A method to generate long-lived isomeric states effectively for Mossbauer applications is reported. We demonstrate that this method is better and easier to provide highly sensitive Mossbauer effect of long-lived isomers (>1ms) such as 103Rh. Excitation of (gamma,gamma) process by synchrotron radiation is painful due mainly to their limited linewidth. Instead,(gamma,gamma') process of bremsstrahlung excitation is applied to create these long-lived isomers. Isomers of 45Sc, 107Ag, 109Ag, and 103Rh have been generated from this method. Among them, 103Rh is the only one that we have obtained the gravitational effect at room temperature.Comment: ICAME 05 conference repor

The GALLEX Project

AbstractThe GALLEX collaboration aims at the detection of solar neutrinos in a radiochemical experiment employing 30 tons of Gallium in form of concentrated aqueous Gallium-chloride solution. The detector is primarily sensitive to the otherwise inaccessible pp-neutrinos. Details of the experiment have been repeatedly described before [1-7]. Here we report the present status of implementation in the Laboratori Nazionali del Gran Sasso (Italy). So far, 12.2 tons of Gallium are at hand. The present status of development allows to start the first full scale run at the time when 30 tons of Gallium become available. This date is expected to be January, 1990

NEUTRINO OSCILLATIONS

La détermination de la masse au repos du neutrino reste un des problèmes les plus importants de la physique. Les oscillations de neutrinos procurent des informations sur les interactions faibles et les masses des neutrinos. Beaucoup d'efforts ont été faits pour trouver de telles oscillations. Cet article passe en revue la situation expérimentale et présente les limites qui ont été obtenues jusqu'à présent.The determination of the rest mass of the neutrinos remains one of the most important unsolved problems in physics. Neutrino oscillations provide information on weak interaction mixing and on neutrino masses. Many efforts have been made to search for such oscillations. The paper reviews the experimental situation and presents the limits obtained to date

ENHANCED NUCLEAR RESONANCE SCATTERING IN DYNAMICAL DIFFRACTION OF GAMMA-RAYS

The angular and energy dependence of the dynamical diffraction of gamma-rays in Bragg geometry was studied experimentally. Mössbauer spectra of gamma-quanta diffracted by a pure nuclear Bragg reflecion of a nearly perfect 57FeBO3 single crystal were measured with high angular resolution. In the spectrum taken at exact Bragg position very broad hyperfine resonance peaks were observed. In the spectra just above and below the Bragg angle the reflection peaks were shifted to energy positions above and below resonance. The results are interpreted by means of the dynamical theory and compared with computer calculations