2. Measurement methods
The NAA method is based on irradiating the measured sample
in a neutron field and measuring induced activity. For mercury,
197mHg (half-lifeof23.8h), 197Hg (64.1h)and 203Hg (46.6days)
can be used for NAA. Due to the high activities of other induced
radionuclides(like 24Na, 82Br and 122Sb) present for a few days
after lamp irradiation, 203Hg (from the 202Hg(n,γ)203Hg reaction)is
the most useful for NAA.