Performance parameters of the Hamburg 4 pi whole body radioactivity detector.

Large 4 pi whole body counters allow the use of very low doses of radioactivity in medical research and in routine diagnosis of patients. The electronics of the 4 pi whole body counter in Hamburg (HAMCO) have recently been updated. The detector contains 1360 I of liquid organic scintillator. Experiments combined with extensive computer simulations yielded quantitative information for whole body counters and comparable systems, (1) about physical parameters such as detection efficiency, energy resolution and background count rates which are important for practical performance, and (2) concerning the optical properties of the large volume scintillation counters employed here; these are of interest for the construction of future detectors of related types.