After various nuclear meltdowns of the power plant Fukushima Daiichi in Japan in March
2011, large amounts of radioactive gases were released and distributed in the atmosphere. This
work shows that at various altitudes and areas over Germany an increased concentration of the
radioactive isotope 133Xe could be measured.
This is done by a proceeding extraction of the few containing 133Xe atoms from small air
samples with a highly sensitive gas chromatograph. Following this, a low background measurement
of 133Xe β-decays with miniaturized proportional counters is done. The evaluation of the
initial activity within the air samples is calculated by using the Maximum-Likelihood-Method.
In the end a forward trajectory simulation developed by the DLR (Deutsches Zentrum für Luft
und Raumfahrt) could be confirmed.