BGO crystal (chemical formula Bi4Ge3O12, also known as bismuth germanate crystal) is a scintillation crystal with excellent comprehensive performance. As a new generation of scintillation crystals, BGO is widely used in high-energy physics experiments such as the European Nuclear Research Institute (CERN) large-scale electron-positron collider.

BGO crystal exhibits stable physical and chemical properties, high mechanical strength, high density, high refractive index, and resistance to harsh environments. It shows excellent scintillating performance, for example, high scintillating efficiency, high light yield, fast decay time, and high energy resolution. BGO crystals are widely used in photomultiplier tubes, photoelectric counters, scintillation screens and other devices. This is used to detect high-energy particles, such as beta rays, gamma rays, etc. BGO scintillation crystals, as the direct medium through which dark matter (high-energy electrons and gamma rays) may annihilate, play an important role in dark matter detection. In addition, it has been extensively studied due to its short decay time in the visible band, photoluminescence, and two-photon absorption under the action of high-power lasers. These characteristics make BGO suitable for use as a scintillator in the fields of medicine, geological prospecting, nuclear physics, high energy physics and nonlinear optics.


Parameter

Material Features

Chemical formulaBi4Ge3O12
Mohs hardness (Mho)5
Melting point (℃)1044
HygroscopicityNo
Cleavage planeNo
Density (g/cm3)7.13
Solubility (g/100gH2O)N/A
Thermal expansion coeff (C-1)7*10-6
Thermal conductivity coeff (W/mk)11.72

Scintillator Properties

Wavelength(Max. Emission) (nm)480
Wavelength range (nm)375~650
Decay time (ns)300
Light yield (photons/keV)8~10
Refractive index2.15
Energy resolution (%)12
Radiation length (cm)1.118
Optical transmission (um)0.15-12.5
Transmittance (%)>90(0.35-9um)
Reflection loss/surface (%)6.80
Afterglow (%)0.005@3 ms
Neutron capture cross-section (bams)1.47
Photoelectron yield [% of NaI(Tl)] (for γ-rays)15 – 20

Spertrum

Feature

  • High density
  • High light yield
  • Fast decay time
  • Chemically inert
  • Dark matter detection
  • Large nonlinear coefficient
  • Excellent scintillating efficiency

Application

  • Positron tomography scanner
  • Electronic Collider
  • High-energy ray experiment
  • Dark matter detection

Reference

[1]  Valais I ,  Michail C ,  David S , et al. A comparative study of the luminescence properties of LYSO:Ce, LSO:Ce, GSO:Ce and BGO single crystal scintillators for use in medical X-ray imaging[J]. Phys Med, 2008, 24(2):122-125.
[2]  Takahashi H ,  Yonetani M ,  Matsuoka M , et al. A thermal-neutron detector with a phoswich system of LiCaAlFand BGO crystal scintillators onboard PoGOLite[C]// Nuclear Science Symposium Conference Record (NSS/MIC), 2010 IEEE. IEEE, 2010.
[3]  Limkitjaroenporn P ,  Sangwaranatee N ,  Chaiphaksa W , et al. Comparative Studies of the Light Yield Non-Proportionality and Energy Resolution of CsI(Tl), LYSO and BGO Scintillation Crystals[C]// Materials Science Forum. 2016.

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