BaF2 Scintillation Crystal

Barium fluoride (BaF2) has an emission component with subnanosecond decay time that yields very fast timing. It is a scintillator showing two wavelengths of emission (310 nm and 295 nm). The emission at 220nm has an emission with sub nanosecond decay time interesting for timing applications. Using special electronics, time resolutions around 200 ps are possible for small detector geometries.

Application

1 ) Positron lifetime studies

2 ) Time of flight measurements

3 ) Positron emission tomography (PET)

4 ) Certain high-energy physics applications

Features

1 ) Subnanosecond decay time

2 ) Two wavelengths of emission (310 nm and 295 nm)

Properties

Density (g/cm3)

4.88

Melting Point (K)

16.27

Thermal Expansion Coefficient (C-1)

18.4 x 10-6

Cleavage Plane

<111>

Hardness (Mhos)

3

Hygroscopic 

Slightly

Wavelength of Emission Max. (nm)

310 / 220(195)

Lower Wavelength Cutoff (nm)

135

Refractive Index @ Emission Max.

150(310nm) 1.54(220nm)

Primary Decay Time (ns)

630 (slow) / 0.6-0.8 (fast)

Light Yield (photons/KeV)

10 (slow)  / 1.8 (fast)

Photoelectron Yield (% of NaI(Tl)) (for γ-rays)

16 (slow) / 3 (fast)