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4 bismuth germanate bgo scintillation crystal detectors
BGO is an excellent Gamma-ray detector, for some background info check the nasa website www.nasa.gov and search on BGO, also check this link http://imagine.gsfc.nasa.gov/docs/introduction/gamma_detectors.html
All the crystals I offer are clean and in very good condition with no large chips. Most of the crystals have some minor flaking or roughness on the edges and corners (see pictures below) but this commonly occurs during manufacturing and should not have any measurable effect on performance.
Below is what the crystals look like when exposed to an X-ray beam:
I am also selling separately square faced Photomultiplier Tubes ( PMT's ) that work well when coupled with these scintillation crystals as they cover the entire face of PMT. For more information see my other listings.
Below is some information on the properties and specifications of BGO:
Bismuth Germanate, also called BGO, is a high density scintillation material. Due to the high atomic number of bismuth (83) and its high density, BGO is a very efficient -ray absorber. Because of its high effective Z value, the photofraction for -ray absorption is high, which results in a very good photo-peak to Compton ratio. The scintillation light can be detected with standard photomultiplier tubes. The scintillation intensity of Bismuth Germanate is a strong function of the temperature. The decay time of BGO is about 300 ns at room temperature, which is comparable to that of NaI(Tl). However, the afterglow is much lower, typically about 0.005% after 3 ms.
BGO is relatively hard, rugged, non-hygroscopic crystal which does not cleave. The material does not show any significant self absorption of the scintillation light. The crystal housing can be kept simple since no hermetic air-tight sealing is required. BGO can be machined to various shapes and geometries. BGO scintillation crystals are used in applications where a high photofraction is required (as in PET scanners) or because of its high density (as in Compton suppression spectrometers).
Wavelength of emission maximum; 480 nm
Lower wavelength cutoff; 320 nm
Refractive index at emission maximum; 2.15
Afterglow (after 3ms); 0.005 %
Light yield; 8 - 10 x 103 photons/MeV
