Thallium-doped Cesium Iodide (Tl:CsI) is a widely used inorganic scintillation crystal that combines high light output, good energy resolution, and improved environmental robustness compared to many traditional scintillators. By introducing thallium activator ions into the CsI lattice, Tl:CsI efficiently converts ionizing radiation into visible light suitable for detection by silicon photodiodes (Si-PD) and other solid-state sensors.
With its broad emission spectrum, moderate decay time, and lower hygroscopicity than NaI(Tl), Tl:CsI is a practical and reliable choice for a wide range of medical, industrial, security, and research applications.
Key Properties of Tl:CsI
- High Light Yield: Produces strong scintillation signals, enabling clear radiation detection.
- Moderate Scintillation Decay: Typical decay time of ~1 μs, suitable for applications where ultra-fast timing is not critical.
- Excellent Energy Resolution: Supports accurate discrimination of radiation energy levels.
- Lower Hygroscopicity: Less moisture-sensitive than NaI(Tl), simplifying handling and packaging requirements.
- Broad Emission Spectrum: Emission from ~350 nm to 700 nm, well matched to silicon photodiodes (Si-PD).
Crystal & Scintillation Properties
| Property | Value |
|---|---|
| Chemical Formula | CsI:Tl |
| Density | 4.53 g/cm³ |
| Melting Point | 621 °C |
| Emission Peak | 550 nm |
| Emission Range | 350 – 700 nm |
| Decay Constant | ~1000 ns |
| Light Output | ~47% (relative) |
Typical Applications of Tl:CsI
- Medical imaging (CT scanners and nuclear medicine detection systems)
- Industrial non-destructive testing (NDT) (gamma-ray inspection and quality control)
- Security screening systems (airport and cargo radiation inspection)
- High-energy & nuclear physics research (particle and gamma-ray detection)
- Heavy charged-particle detection (operation under strong γ-ray background)
Shape Optics Tl:CsI Capabilities
Shape Optics Technologies supplies high-quality Tl:CsI scintillation crystals and crystal blanks, supported by over 20 years of optical and crystal manufacturing expertise.
Product & Service Offering
- Tl:CsI scintillation crystals
- High-quality Tl:CsI crystal blank materials
- OEM and custom scintillator solutions
Why Choose Thallium-Doped Cesium Iodide (Tl:CsI)?
Tl:CsI is an excellent choice for applications requiring:
- High light output with good energy resolution
- Moderate timing performance
- Improved handling compared to highly hygroscopic scintillators
- Compatibility with silicon photodetectors
Its balance of performance, robustness, and cost-effectiveness makes Tl:CsI a dependable scintillation material across medical, industrial, security, and research sectors.