Check Sources

Alpha, Beta, Gamma and Mixed Radiation

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.

Disc Sources +/- 25% in single quantities cost $85 each. Secondary calibration (+/- 5%) costs $150 extra per check source. Europium 152, multi-lined source, 1 in. disc, 1 uCi, costs $150 each. Non-standard disc source <= 10 uCi costs $150, and $175 for Eu-152







Ba-133 S
1 uci
10.7 years
81.0, 276.3, 302.7, 355.9, 383.7
CD-109 S
1 uci
453 days
CS-57 S
1 uci
270 days
122.1, 136.4
Co-60 S
1 uci
5.27 years
Gamma, Beta
1173.2, 1332.5, Beta: 317.9
Cs-137 S
1 uci
30.1 years
Gamma, Beta
32, 661.6, Beta: 511.6, 1173.2
Cs-137 S5
5 uci
30.1 years
Gamma, Beta
32, 661.6, Beta: 511.6, 1173.2
1 uci
32, 661.6, 1115.5
1 uci
312 days
Na-22 S
1 uci
2.6 years
511.0, 1274.5
Po-210 S
0.1 uci
138 days
Sr-90 S
0.1 uci
Zn-65 S
1 uci
244 days

RSS-2 GM Resolving Time Set

Includes two active disc sources, one blank

This set is used for determining the resolving time of GM Counters. It consists of three half discs, two of which contain 5 micro curies of Tl-204 plus a third half disc with no activity. The count-rate of each half disc plus the blank (to maintain constant geometry) is measured and then both active half discs are combined for a measurement with high count-rate. The counting loss may now be calculated by adding the rates from each half disc and comparing the result to the count-rate with both halves combined.

RSS-2 Disc Source kit.............$195 each

RSS-3 Alpha, Beta, Gamma Disc Source Set

Includes three disc sources

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.

RSS-3 Disc Source Kit..................$255

RSS-5 Alpha, Beta, Gamma Disc Source Set

Includes five disc sources

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.

RSS-5 Disc Source Kit....................$330

RSS-8 Alpha, Beta, Gamma Disc Source Set

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.

RSS-8 Disc Source Kit...................$480

PO-210 Alpha Source Kit

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.

Po-210 Alpha Source Kit...................$125


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