Cadmium tungstate (CdWO4 or CWO) is a monoclinic crystal with a wolframite structure and has good comprehensive scintillation properties. The peak scintillation wavelength of CdWO4 crystal is 480 nm (with emission range between 380-660 nm),  and efficiency of 13000 photons/MeV,when it is hit by gamma rays and x-rays. High luminous efficiency, short afterglow time, large X-ray absorption coefficient, strong resistance to radiation damage, and high material density, so that CdWO4 crystal is widely used in nuclear inspection, γ camera, X-CT, High energy physics, and container inspection, etc. The combined application of CdWO4 crystal and B4C can form a compact gamma-ray and neutron radiation detector. At the same time, CdWO4 crystals can be used to detect rare nuclear processes, such as double β decay, other rare α, and β decay.


Parameter

Material Features

Chemical formulaCdWO4
Density (g/cm3)7.9
Melting point (℃)1598
Hardness (Mho)4-4.5
HygroscopicNo
Cleavage<110>
Thermal expansion coeff (C-1)10.2*10-6

Scintillator Properties

Wavelength(Max. emission) (nm)490
Wavelength range (nm)380~800
Decay time (ns)14000
Light yield (photons/keV)12~15
Light output relative to Nal(Tl) (%)50
Refractive index2.2-2.3
Radiation length (cm)1.06
Afterglow (%)<0.1

Spertrum

Feature

  • High luminous intensity
  • Good light transmittance
  • Low radiation damage
  • Short duration of afterglow
  • High density
  • High X-ray absorption coefficient
  • Low intrinsic radioactivity level

Application

  • Medical Computed Tomography (CT)
  • Optical recording device of Phase change
  • Positron emission tomography (PET)
  • The well logging
  • The control and inspection for industrial process
  • Nuclear weapons and waste monitoring

Reference

[1]  Barabash A S ,  Belli P ,  Bernabei R , et al. Development of CdWO4 crystal scintillators from enriched isotopes for 2γ-decay experiments[C]// IEEE International Conference on Oxide Materials for Electronic Engineering. IEEE, 2016.
[2]  Belli P ,  Bernabei R ,  Boiko R S , et al. Development of enriched 106CdWO4 crystal scintillators to search for double beta decay processes in 106Cd[J]. Nuclear Instruments & Methods in Physics Research, 2010, 615(3):301–306.
[8]  Belli P ,  Bernabei R ,  Boiko R S , et al. First Results of the Experiment to Search for 2β Decay of 106Cd with the Help of 106CdWO4 Crystal Scintillators[J]. American Institute of Physics, 2010.

Leave a Reply

Your email address will not be published. Required fields are marked *