NaI(Tl) — sodium iodide doped with thallium — is the most widely used scintillation material in nuclear spectroscopy and the industry standard for gamma-ray detection. Key specifications include: high light yield (approximately 38,000 photons/MeV), making it one of the brightest inorganic scintillators; density of 3.67 g/cm³, providing efficient stopping power for gamma rays; scintillation decay time of 250 ns, suitable for moderate count rate applications; typical energy resolution of 6.5-7.5% FWHM at 662 keV; and emission wavelength peaked at 415 nm, well-matched to standard PMT photocathodes. NaI(Tl) is readily available in a wide range of standard sizes and is the most cost-effective option for routine gamma spectroscopy. Berkeley Nucleonics offers NaI(Tl) detector assemblies in standard and custom configurations.