The gamma spectrometer is located in a laboratory outside of the EAST experimental hall. The thickness of the hall concrete wall is 1.5 m, and the wall has a collimator (diameter of 4 cm) that is perpendicular to the plasma on the equatorial plane. The wall is thick enough to provide good measurement conditions for the spectrometer. A neutron attenuator is used to stop possible neutrons before they reach the detector. The neutron attenuator is made of polythene and located inside the collimator.