The use of associated particle timing based on the D + D reaction for elemental analysis of bulk samples such as the human body.

The use of associated particle timing based on the D + D reaction has been demonstrated for elemental analysis of bulk samples such as the human body. The neutron energy of 2.8 MeV eliminates the background from organic matrices. The nanosecond timing of a HPGe detector renders it possible to identify the spatial origin of the measured gamma radiation limiting the sensitive area to a single pixel. By this technique the background could be reduced by a factor of > or = 1000, but the present set-up has achieved an effective factor only in the range 20-100, due to losses in the generation of timing signals. The very clean gamma-spectra obtained permit the use of high efficiency scintillation detectors. Sensitivities for measuring Al, Ti, and Fe are presented at an extrapolated dose of 10 mSv.