CsI(Tl) Scintillation crystal

CsI(Tl) scintillator has a light output of 54 photons/keV and is one of the brightest scintillators known.

The maximum of the broad emission is situated at 550nm and the emission is, therefore, not well matched to a bialkali photocathode photomultiplier tube. However, since most of its emission in the long-wavelength part of the spectrum (>500nm), it is well-suited for photodiode readout.

CsI(Tl) has very good stopping power, is slightly hygroscopic and with good plastic mechanical properties. Combined with relatively good radiation hardness properties, CsI(Tl) is also well suited for High Energy Physics. It is used in Phoswiches for whole-body counting and X-ray astronomy as the “guard crystal” with typically a thin NaI(Tl) as the primary detector.

The decay time of CsI(Tl) consists of more than one component. The fastest component has a value of about 0.6µs, the slowest 3.5µs. For excitation with highly ionizing particles, such as α-particles or protons, the ratio between the intensity of these two decay components varies as a function of the ionizing power of the absorbed particle. CsI(Tl) scintillation crystals can therefore be used for particle discrimination using pulse shape analysis. It has been demonstrated that nuclei up through Li can be identified this way.

CsI is relatively soft and plastic and does not cleave. Because it has no cleavage plane, it is quite rugged – which makes it well-suited for well logging, space research or other applications where severe shock conditions are encountered.

• High density, High γ-ray stopping power
• Emission wavelength at 550 nm
• Compatible with photodiode readout

Recent advances in CsI(Tl) array manufacturing have resulted in afterglow reduction, improved light output, and afterglow uniformity, which make an excellent choice for security inspection and nuclear imaging. Read more details,