Characterization of the Budapest prompt-gamma spectrometer by Monte Carlo simulations

The interpretation of prompt gamma-ray spectra and the prediction of the detection limits and run times for samples require the knowledge of the detector response function. The detector system used at the Budapest Prompt-Gamma Activation Analysis facility consists of an HPGe detector and a Bismuth Germanate Compton suppressor within lead shielding. The aim of the present study is to characterize this detector with Monte Carlo calculations and verify the results against measurements of radioactive and (n,γ) sources. We have used the Monte Carlo simulation program MCNP-CP to produce both unsuppressed and suppressed spectra and to study the effect of the detector parts on the shape of the spectrum.