133Ba

133Ba is an isotope of the chemical element Barium. Barium has the atomic number 56, meaning each atom of barium contains 56 protons. Isotopes of an element have the same number of protons but different numbers of neutrons. Therefore, 133Ba has 56 protons and 133 - 56 = 77 neutrons.

This particular isotope, 133Ba, is known for its radioactive properties. It undergoes radioactive decay, primarily through electron capture, transforming into a stable isotope of Cesium, specifically 133Cs. During this decay process, 133Ba emits gamma rays, which are a form of electromagnetic radiation. The half-life of 133Ba, the time it takes for half of a sample to decay, is approximately 10.5 years.

Due to its characteristic gamma ray emissions, 133Ba has found applications as a gamma ray reference source in nuclear instrumentation and calibration. It is used to check the performance of radiation detectors and spectrometers. The controlled decay of 133Ba allows for precise energy calibration. While it is a radioactive material and requires careful handling, its use in these scientific applications is well-established.