CsI(Tl) Scintillators

CsI(Tl) Introduction:

Cesium Iodide crystals doped with Thallium (CsI(Tl)) are not new to the industry, are inorganic alkali metal halide crystals grown in high temperature furnaces, and are  one of the most widely used scintillation material in the World. CsI(Tl) is used traditionally in nuclear medicine, environmental survey, security, and medium-energy physics.  NaI(Tl) crystals make remarkable scintillators and can also be combined as custom built arrays:


The CsI(Tl) Advantage:

Cesium Iodide crystals doped with Thallium (CsI(Tl), like NaI(Tl) crystals, are inorganic alkali metal halide crystals grown in high temperature furnaces.

However, unlike NaI(Tl) crystals CsI has a higher intrinsic efficiency than NaI but less than BGO.   Csl also has poorer energy resolution than NaI. However, CsI has much faster pulse light decay and finds use in timing applications but the wavelength of its photon output is poorly matched to most PMT's.

On the other hand, CsI is less brittle than NaI and thereby may be subjected to more severe shock and vibration conditions than NaI detectors, is significantly less hygroscopic than NaI but more than BGO:


comparison count of NAL(Tl) to other types

CsI(Tl) Scintillator Materials Used:

Casing MaterialAluminiumStainless SteelTitanium
ShapeSquare or CylindricalCylindricalCylindrical
HeadNone ThreadedNone ThreadedThreaded
Temperature-35C to 50C (-31F to - 122F)-35C to 175C (-31F to - 347F)35C to 175C (-31F to - 347F)
VibrationNot recommended to be used in vibration environmentsRandom 5g 50-500Hz 15 minute duration per axis; 2 axis totalRandom 30 g 30-1000Hz 30 minute duration per axis; 2 axis total
Max Emission (nm)550550550
Refractive Index1.791.791.79

*MWD "measurement while drilling"

CsI(Tl) Scintillator Common sizes and part-numbers:

TypeShapeOutside Casing SizePart No.
RegularCylindrical1" (25.4 mm) x 1" (25.4 mm)FPCSA-100-500
RegularCylindrical2" (25.4 mm) x 2" (50.8 mm)FPCSA-200-200
RegularCylindrical 3" (25.4 mm) x 3" (76.2 mm)FPCSA-300-300
RuggidizedCylindrical1" (25.4 mm) x 5" (127.0 mm)FPCSS-100-500
RuggidizedCylindrical1" (25.4 mm) x 6" (152.4 mm)FPCSS-100-600
RuggidizedCylindrical1" (25.4 mm) x 6.5" (165.1 mm)FPCSS-100-650
RuggidizedCylindrical1.25" (31.75 mm) x 5" (127.0 mm)FPCSS-125-500
MWDCylindrical1" (25.4 mm) x 5" (127.0 mm)FPCST-100-500
MWDCylindrical with Threaded Head1" (25.4 mm) x 5" (127.0 mm)FPCST-100-500
MWDCylindrical1" (25.4 mm) x 6" (152.4 mm)FPCST-100-600
MWDCylindrical with Threaded Head1" (25.4 mm) x 6" (152.4 mm)FPCST-100-600
MWDCylindrical1.25" (31.75 mm) x 5" (127.0 mm)FPCST-125-500
MWDCylindrical with Threaded Head1.25" (31.75 mm) x 5" (127.0 mm)FPCST-125-500
CsI(Tl) Scintillator Ordering and Custom Sizes:

FlashPoint can manufacture to meet your custom diameter and length requirements. To learn more and to place an order please contact us.

CsI(Tl) Scintillator Packaging:


FlashPoint takes great care in shipping your order to you.  Each scintillator is packaged individually inside tough industrial strength tubes that you can later re-use to ship or store other valuable components.

CsI(Tl) Scintillator Delivery Terms:

Please contact us to confirm current inventory and to confirm delivery date based on size of order and location of delivery.  We do accept transportation on your shipping account.

CsI(Tl) Scintillator Warranty:

FlashPoint provides a 1 year "no-nonsense" limited warranty on its Scintillator Products