The ICS-4000 radionuclide identifier provides a 4000-channel multi-channel analyzer and CZT detector to accurately display lab-quality spectra of gamma ray photons with energies from 10keV to 2MeV. Built-in software provides radionuclide identification and dose rate information. Two megabytes of flash memory provide non-volatile storage of hundreds of data files. Spectra and other data can be downloaded to a PC via RS-232. Powered by a rechargeable Lithium-ion battery pack, the unit will provide up to 24 hours of continuous measurement on a single charge. The battery pack is removable, and can be replaced with an auxiliary power pack for extended operation.