Influence of 210Pb on the continuous background of gamma-ray spectrometers

The contribution of the 210Pb activity in gamma-ray spectrometer's lead shields to the spectrometer background was determined on the basis of the time dependence of the count rate in the background continuum. The time dependence, reflecting the decay of 210Pb, was measured over a time interval of about 10 years. It is shown that the maximum contribution to the spectrometer background due to 210Pb is around 200 keV, and that the largest fractional contribution to the total background is in the energy interval from 100 to 300 keV.