Isotope Generator Kit (Barium-137 m) - SN-7995A



This Cs-137/Ba-137 m Isotope Generator is used to demonstrate the properties of radioactive decay. Based on the original Union Carbide patented design, it offers exceptional performance, ease-of-use and safe operation.

Each generator contains 10 µCi of Cs-137. The generator can produce up to 1000 small aliquots of the short-lived Ba-137m isotope with a half-life of 2.6 minutes.

Each generator is supplied with 250 mL of eluting solution (0.9% NaCl in 0.04M HCl). The parent isotope Cs-137 with a half-life of 30.1 years beta decays (94.6%) to the metastable state of Ba-137m. This further decays by gamma emission (662 keV) with a half-life of 2.6 min. to the stable Ba-137 element. During elution, the Ba-137m is selectively "milked" from the generator, leaving behind the Cs-137 parent. Regeneration of the Ba-137m occurs as the Cs-137 continues to decay, re-establishing equilibrium in less than 1 hour.

Approximately 30 minutes after elution, the residual activity of the Ba-137m sample has decayed to less than one thousandth of its initial activity, making it safe for disposal. When used with the eluting solution supplied, bleed through of the parent Cs-137 is less than 50 Bq/mL, affording a long working life. Each kit is supplied with the generator, syringe, tube, 250 mL of solution and a storage case.

The source is USNRC License Exempt (US only).  Outside the US, consult local laws and regulations.


PASCO Radioactive Source Disclaimer - Please review prior to purchase

Before purchasing PASCO radioactive sources:

Local, national, and international regulations may restrict the purchase, storage, transport, use or disposal of radioactive sources.  Please  consult your local regulations to ensure your compliance before you purchase radioactive sources.

  • PASCO advertised sources are direct shipped to customers from Spectrum Techniques (  Please review their "Terms and Conditions" page before purchasing.
  • Once shipped, purchased sources are "Non-Cancellable" and "Non-Returnable". Radioactive sources cannot be returned under any circumstances including "End of  Life" disposal.


  • PASCO generally advertised sources are USNRC License Exempt (US only). 
  • International exempt sources (per the International Atomic Energy Agency) are  available for international customers or by request.