Gamma-ray background induced in a double Ge(Li) spectrometer at balloon altitudes in the Southern Hemisphere

Abstract

A double coaxial Ge(Li) spectrometer has been flown for the first time in December 1983 from the Southern Hemisphere. Despite an electronics failure which shortened the flight duration, the induced background at ceiling in the diodes can be studied. Nevertheless, the low statistics of the data requires some caution in the identification of the features of the lines. During the flight, different anticoincidence modes were operated to estimate the local production. The atmospheric 511 keV line results show that the fluxes detected by the upper diode are in good agreement with previous measurements, and, at the same time, indicate a probable contamination of the lower diode. The techniques used with a double coaxial Ge(Li) seem to demonstrate a better method to reject the induced background in the upper diode (the heart detector) than with the single Ge(Li) telescope.