We use the following list of sources for calibration of the Xray detectors:

- 241Am_low [40.5 kBq (3%), 01.10.2020 12:00 UTC] [URL=https://elog.gsi.de/esr/X-Ray+Lab/201006_131944/20-007_241AM_40kBq.pdf]SpecSheet[/URL]

- 241Am_high [OM 666, 430 kBq (3%), 19.09.2006]

- 133Ba_low [40.8 kBq (3%), 01.10.2020 12:00 UTC] [URL=https://elog.gsi.de/esr/X-Ray+Lab/201006_131944/20-003_133Ba_40kBq.pdf]SpecSheet[/URL]

- 57Co [427 kBq (3%), 01.10.2020 12:00 UTC] [URL=https://elog.gsi.de/esr/X-Ray+Lab/201006_131944/20-005_57Co_400kBq.pdf]SpecSheet[/URL]

Was another 133Ba source used???