Telescope calibration for gamma spectroscopy with a new Ge(Li) diode configuration
Abstract
A telescope was developed to measure gamma-rays in the energy interval 10-1500 KeV, using two Ge(Li) diodes of 40 cu cm each, coaxially mounted in the same cryostat and an anticoincidence Nat(T2) shielding system. This new configuration allows a much better signal to noise ratio due to the lower diode operating in anticoincidence with the upper one and a high energy resolution. The results of the telescope calibrations with the calibrated sources Am-241, Na-22 and Eu-152 are described. From the analysis of the data obtained in the sum coincidence mode, a minimum detectable flux at 511 KeV is estimated to be 0.002 photons /sq cm/s with a statistical significance of 3 sigma for 10 hours of observing time at 3 mb of residual atmosphere. That is about the minimum line flux emitted by the Galactic Center. The measurement of the flux at this line would confirm the time variability observed using data obtained through HEAO-3 satellite.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- September 1983
- Bibcode:
- 1983STIN...8414083B
- Keywords:
-
- Calibrating;
- Gamma Ray Spectrometers;
- Gamma Ray Telescopes;
- Germanium Diodes;
- Radiation Measuring Instruments;
- Cryostats;
- Flux Density;
- Galactic Nuclei;
- Heao 3;
- Lithium;
- Signal To Noise Ratios;
- Statistical Analysis;
- Astronomy