A reference material for evaluation of Cs radiochronometric measurements.

A new nuclear forensic reference material has been characterized as a standard for radiochronometric determination of the model purification date for Cs sources. The purification date of a radioactive source is a potentially diagnostic nuclear forensic signature for determining the provenance of a radioactive material. Reference values have been measured for the attributes needed to use the Cs/Ba chronometer: the molality (reported here as nmol g) of Cs and of the radiogenic portion of Ba in the material (hereafter referred to as Ba*).