On Thursday 25 April, two schoolgirls visited us as part of Girls’ Day. In the morning we inspected the room in our building and glued one of the photodiodes to the bismuth germanium oxide scintillator. Then we showed and explained two of our current experimental setups. The set-up with the BGO crystal was going to be placed in the vacuum chamber. Together with the students, we took all the necessary precautions and transferred the whole setup to the laboratory with the vacuum chamber. In preparation, several cables were soldered from the test cell to the vacuum feedthrough and further to the readout electronics. These were extensively tested by the girls before commissioning, as were all the other feedthroughs and the power supply. After the lunch break, the measurement setup was put into operation and after successful tests, the vacuum chamber was closed and the air pumped out. As the light output in the BGO is temperature dependent, the next step is temperature calibration. Unfortunately, there is currently a problem with the cooling system, so this test will be delayed. However, with the help of the two students, the test setup in the pump-down vacuum chamber was successfully put into operation.
