The spectrometry of promptly emitted; rays after thermal neutron capture is
used for a complete, nondestructive, isotopic material analysis del eloped
at the Physikalisch-Technische Bundesanstalt (PTB), This method is indepen
dent of the sample dimensions and its state of aggregation, Furthermore all
isotopes are detected by multichannel analysis, simultaneously. Isotopic m
ass differences have been determined up to now with a relative uncertainty
of 3 x 10(-10) [1].