Half-life: 28,8 years
Main emission lines: linear spectrum
Used as a reference source in beta-sensitive dosimeters. The spectrum has no characteristic peaks, all spectra of beta emitting sources are linear, making it very difficult to identify the isotope. Also, strontium-90 is often a companion of cesium-137, although it is extremely difficult to distinguish it from the other components of the spectrum. Radiacode-101 is more sensitive not to the beta particles themselves, but to the bremsstrahlung that occurs when it interacts with environmental materials.