RAP Scintillation Probe / CsI (Tl) - Cesium Iodide Thallium

[ click the picture ]

Nuclemed - click to enlarge Nuclemed - click to enlarge

The CsI (Tl) crystal used in Radiation Alert® Probes has a higher atomic number, is more rugged, and less hygroscopic than a typical Nal detector. The improved gamma ray absorption allows a thinner crystal to be used, effectively reducing the background count rate.


Type-CsI (Tl) crystal (Cesium Iodide Thallium)

RAP640 - 1.0" dia x 1.0" thick (25.4 x 25.4mm)

Radiation Detected

RAP640 - gamma 8 keV to 3 MeV.

Typical Absorption 70% at 600 keV, 50% at 840 keV

Probe Construction

Anodized aluminum housing. Approximate size: length 7-7.5 inches, diameter 1.5 inches. Connectors-Standard MHV. Cable (Optional)-Straight RG59/u, length 3.5 feet.

Temperature Range

-25°C to 40°C (-4°F to 104°F)

Humidity Range

0 to 90% Relative Humidity.


RAP640-Approx. 290 g (10.25 oz.) without cable


One year limited.