Pure (undoped) CsI (Cesium Iodide) is a high-performance fast scintillator crystal widely used in particle physics, nuclear instrumentation, and time-resolved radiation detection. Unlike doped variants such as CsI(Tl), pure CsI exhibits intrinsic UV scintillation with a sub-10 ns decay time, making it an excellent choice for high count-rate and timing-critical experiments. With an emission peak near 305 nm, pure CsI is well matched to UV-sensitive PMTs, MCPs, and SiPMs, enabling precise temporal resolution in TOF systems, calorimeters, and fast imaging detectors. Its high effective atomic number (Z) provides strong stopping power for X-rays and gamma rays, while its radiation hardness ensures stability in intense radiation environments. Pure CsI crystals are commonly deployed in university research laboratories, national facilities, and custom detector prototypes, where timing accuracy outweighs maximum light yield. Typical Research Applications Time-of-flight (TOF) particle detection High-energy physics calorimeters Fast X-ray and gamma-ray spectroscopy Nuclear and particle beam diagnostics Ultrafast scintillation imaging systems Available Options Custom sizes: blocks, cylinders, plates Optical-grade polishing Tight dimensional tolerances Optional encapsulation or sealing for moisture protection Engineering note: Pure CsI provides significantly faster response and lower afterglow than CsI(Tl), but with reduced light output. It is best suited for timing-dominated detector designs Below is a clear comparison of the properties of pure CsI, CsI:Tl, and CsI:Na: Comparison of CsI, CsI:Tl, and CsI:Na Property CsI:Tl CsI:Na Pure CsI Light Yield (photons/keV) ~56 ~40
