In order to improve the sensitivity for the quantification of trace elements, we propose the combination of prompt gamma-ray
analysis (PGA) and a multiple gamma-ray detection method. A new Ge detector system for multiple prompt gamma-ray analysis
(MPGA) was constructed at the neutron guide-hall of the JRR-3M reactor of the Japan Atomic Energy Agency (JAEA). The first
demonstration of this system was given with a plastic sample containing traces of cadmium. The quantification limit of cadmium
in a plastic sample was found to be about 0.1 ppm.