


BGO (Bi4Ge3O12) is a high Z, high-density scintillation material. Due to the high atomic number of bismuth (83) and the material's high density of 7.13 g/cm3, BGO is a very efficient gamma-ray absorber. Given the high Z value of the material, the photo fraction for gamma-ray absorption is high and as a result, very good peak-to-total ratios are observed.
The radioactivity in BGO can make BGO unacceptable for some applications. We have developed a production process that significantly reduces the natural background, making our BGO well-suited for most applications.
BGO can be machined to various shapes and geometries. Since BGO is not hygroscopic it does not require a hermetic package. Arrays can be produced for imaging applications such as medical PET and security. For Physics experiments such as anti-Compton shields, crystals are typically packaged into larger annulus type detectors with multiple readout devices such as photomultiplier tubes.
Properties | Value |
---|---|
Density [g/cm3] | 7.13 |
Melting point [K] | 1323 |
Thermal expansion coefficient [C-1] | 7 x 10-6 |
Cleavage plane | None |
Hardness (Mho) | 5 |
Hygroscopic | No |
Wavelength of emission max. [nm] | 480 |
Lower wavelength cutoff [nm] | 320 |
Refractive index @ emission max | 2.15 |
Primary decay time [ns] | 300 |
Light yield [photons/keVγ] | 8-10 |
Photoelectron yield [% of NaI(Tl)] (for γ-rays) | 15 - 20 |
Temperature response | -1.2%/C |
Neutron capture cross-section | 1.47b |
Afterglow | @ 20ms 150ppm |