A very low background HPGe detector operating deep underground at 4800 m water equivalent.
A very low background HPGe detector has been installed in the Fréjus underground laboratory in order to investigate radioactive contaminations. The main features and capabilities of the detector are described here.
The Fréjus nucleon decay detector
Abstract The characteristics, trigger and monitoring systems, data acquisition as well as the performance of the Frejus nucleon decay detector are presented.
A new method of near field analysis
The problem of the accurate determination of the total electromagnetic field produced by a current distribution on a circular disc type aperture is examined. For comparison of the near and Fresnel region solutions, an exact Maxwellian integral is used as the starting point. Aperture and space coordinates are separated by the use of Bessel function addition theorems, allowing the field to be expressed as a sum of terms containing radial and angular integrals. The radial integrals involve only the disc (aperture) distribution and coordinates while the angular integrals involve only the elevation angle. The distance from origin appears implicitly in the series coefficients. These integrals are suitable for high speed computations and have been evaluated for a number of cases. The results are compared with the small angle and general Fresnel formula values for various observation angles, distances from the aperture, and aperture distributions.