Lead carbonate, a new fast, heavy scintillator

The authors describe the scintillation properties of lead carbonate (PbCO₃), a newly discovered, heavy (6.6 g/cm³ ), inorganic scintillator. Its fluorescence decay lifetime, measured with the delayed coincidence method, is described by a sum of three exponentials. The emission spectrum peak is centered at a wavelength of 475 nm and drops to less than 10% of its peak value at 370 nm and 580 nm. The authors were unable to obtain an optical quality crystal of pure PbCO₃, but when a 3 mm cube of a cerussite (a naturally occurring mineral form of PbCO₃) is excited with 511 keV photons, a photopeak with a 42% full width at half maximum is observed at approximately 9% the light output of a bismuth germanate (BGO) crystal with similar geometry. The light output increases rapidly with decreasing temperature, plateauing at twice the light output of BGO at approximately -40°C. The short fluorescence lifetime, high density, and reasonable light output of this new scintillator suggest that it would be useful for applications where high counting rates, good stopping power, and nanosecond timing are important, such as medical imaging and nuclear science