Betha Decays

Dr. Chien-Shiung Wu (Shanghai, China, May 31, 1912 – New York, USA, February 16, 1997) was a nuclear physicist who studied beta-decay (a weak interaction in which one of the neutrons in the nucleus of an atom decays into a proton and an electron; the proton enters the nucleus, forming an isotope, and the electron is emitted as a beta-particle). In 1956, Madam Wu did experiments showing that parity is not conserved in weak interactions (demonstrating parity violation in the nuclear beta decay in cobalt 60). Her experiments supported T. D. Lee and C. N. Yang’s revolutionary idea that parity was not conserved in weak interactions (parity conservation had been a basic assumption in physics). Madam Wu worked on the Manhattan Project (a secret US project during World War 2 to develop an atomic bomb in order to defeat Hitler), developing a process for separating the uranium isotopes U²³⁵ and U²³⁸ by gaseous diffusion. She also helped develop more sensitive Geiger counters (devices that detect radiation). Madam Wu also studied the molecular changes in hemoglobin associated with sickle-cell anemia.