CHAOSjunior is a reduced version of the CHOAS experiment. The sensor head consists of a scintillator of Bismuth Germate Oxide (BGO) and two silicon detectors taken from High Energy Telecope (HET-B) in front of and behind the BGO. Two photodiodes were glued on the hexagonal BGO at opposite sides. The energy deposited in the detectors is proportional to the signals from the detectors. During configuration, the calibration parameter is determined. For this purpose a radioactive source of bismuth isotope 207 Bi is used. The characteristic lines of this source are known relatively precisely and can therefore be used for the calibration. First, the calibration of the HET-B detectors was carried out without BGO. The calculation of the channel names was chosen in following way. CHAOSjunior basically consists of three detectors, one HET-B, the BGO and another HET-B. These are named A,B and C in the direction of particle pass through. The information from the BGO (B) is shared between two channels. These are designated B1 and B2. The two HET-B detectors have only one channel each, these are designated AA and CC respectively.
For calibration of preampfilters the sensor units were stimulated by a radioactive source of bismuth isotope 207 Bi. This isotope was placed in front of the sensor head. The prominent emission lines were taken from NUDAT3 (https://www.nndc.bnl.gov/nudat3/ ). The Compton effect of the γ lines at 569.698 keV and 1060 keV could be well observed for both HET-B signals where the first edge is much more precise. The data recorded was adapted by three models, one for the x-ray peaks and one for each Compton-edge. The models deliver the noise s and the calibration parameters u, which allow the conversion of the signals into keV.
