Radioactive Disc / Check Sources

Single Sources and Kits Available

Several Isotopes to choose from.

Cs-137 disc sourceSingle Check Sources

RSS-3 source kitRSS-3 Source Kit

RS5-3 source kitRSS-5 Source Kit

RSS-8 source kitRSS-8 Source Kit

These sources are supplied as one inch plastic discs. With the exception of the alpha source, the small quantity of radioactive material is sealed in the plastic with epoxy to prevent leakage and contamination. The transmission window is sufficiently thin to transmit both beta and gamma emissions without undue absorption.

The alpha source is of open window construction with the source material bonded to the surface of a silver foil mounted in the recess of the plastic disc. This design yields excellent emission of alpha particles with window losses.

Radioisotope sources are available individually or packaged as sets of three, five, and eight in convenient storage boxes. These items are uncalibrated and of nominal activity to provide a safe, yet inexpensive supply of radioactive material for educational and commercial use. Individual sources for alpha, beta and gamma emissions are available in the following isotopes.

Standard Disc Sources are +/- 25% nominal. Secondary calibration (+/- 5%)is available for added cost. Please call for pricing.

  Isotope Activity Half-life Emissions Energies
Barium-133 Ba-133 1, 5, 10 uci 10.7 years Gamma 81.0, 276.3, 302.7, 355.9, 383.7
Cadmium 109 Cd-109 1, 5, 10 uci 453 days Gamma 88.0
Cesium 137 Cs-137 1, 5, 10 uci 30.1 years Gamma, Beta 32, 661.6, Beta: 511.6, 1173.2
Cobalt 57 Co-57 1, 5, 10, 25, 50, 75, 100 uci 270 days Gamma 122.1, 136.4
Cobalt 60 Co-60 0.1, 0.5, 1 uci 5.27 years Gamma, Beta 1173.2, 1332.5, Beta: 317.9
Europium 152 Eu-152 0.1 to 1 uci 13.52 years Gamma, Beta  
Manganese 54 Mn-54 0.1 to 10 uci 312 days Gamma 834.8
Polonimum 210 Po-210 0.05 to 0.1 uci 138 days Alpha 5304.5
Sodium 22 Na-22 0.1 to 10 uci 2.6 years Gamma 511.0, 1274.5
Strontium 90 Sr-90 0.05 to 0.1 uci 28.5 Beta 546.0
Thallium-204 Tl-204 0.25 to 10 uci 3.783 years Beta 763.4
Zinc 65 Zn-65 0.1 to 10 uci 244 days Gamma 1115.5
Cesium 137 / Zinc 65 Cs-Zn 0.5 uci with 1.0 uci Mixed Gamma, Beta 32, 661.6, 1115.5


The RSS-3 contains 1 each Po-210, Sr-90 and Co-60 emitting a range of alpha, beta and gamma radiations. This set is ideal for demonstration and introductory nuclear labs covering basic characteristics of radiation.


Containing 1 each Cs-137, Co-60, Sr-90, Tl-204 and Po-210, the RSS-5 provides a wide of alpha, beta and gamma emissions making it a popular choice for nuclear science instruction The set contains two beta emitters, two beta/gamma emitters and one alpha source for in-depth studies of radiation.


Designed for gamma spectroscopy, the RSS-8 contains eight different gamma emitting isotopes covering the entire energy range from 32 to 1333 keV. Also included in the set is a mixed source of Cs-137 and Zn-65 which students may use to identify an “unknown” isotope. The set consists of Ba-133, Cd-109, Co-57, Co-60, Cs-137, Mn-54. Na-22 and Cs/Zn.

Polonium-210 Alpha Source

Due its relatively short half-life, the Po-210 alpha source must be replaced on a regular basis. Currently this is the only alpha emitting byproduct material available as a NRC Exempt Quantity which may be held without a radioactive material license.