BC-521, BC-525

Gadolinium Loaded

Gadolinium has the highest thermal neutron capture cross-section of any element. The neutron capture reaction yields beta particles and several gamma rays having total energy of about 8 MeV. Delayed coincidence and pulse shape discrimination techniques can be employed.


The main applications of BC-521 and BC-525 are neutron spectrometry and neutrino research.  Both are formulated with high flash point solvents because they are often used in large volumes.


BC-521 is formulated to yield the highest light output possible as well as long-term chemical stability. The standard gadolinium concentration is 0.5% by weight, but other concentrations up to 1.5% can be supplied. Since the liquid is normally used in large tanks containing several hundred liters, it employs a high flash point solvent for safety purposes.


BC-525 scintillator, with its mineral oil component, has a higher light transmission and higher flash point than traditional gadolinium-loaded liquids. It is also more suitable for use in large tanks containing acrylic plastic components. BC-525 is available with gadolinium concentrations up to 0.5% by weight.


Scintillation Properties BC-521 BC-525
Gadolinium Content 0.5%, w/w
Light Output, %Anthracene 68 55
Wavelength of Maximum Emission, nm 424 425
Decay Time, short component, ns 3.6 3.8
Bulk Light Attenuation, meters >4 >4.5
Density g/cc 0.89 0.88
Refractive index 1.50 1.49
Flash Point 44°C 81°C
Atomic Composition    
No. of H Atoms per cc (x1022) 5.25 6
No. of C Atoms per cc (x1022) 4.00 3.85
Ratio H:C Atoms 1.314 1.56
No. of Electrons per cc (x1023) 2.97 2.99


Data Sheets

BC-521 Gadolinium Loaded Liquid Scintillator

PDF | 155.86 KB
Data Sheets

BC-525 Gadolinium Loaded Liquid Scintillator

PDF | 155.84 KB