The book "Tritium Illumination" offers a comprehensive analysis of the use of tritium, a radioactive isotope of hydrogen, for generating visible light. Through the process of beta decay, electrons are emitted and interact with phosphor materials to produce fluorescent light, a phenomenon known as radioluminescence. This technology does not require electrical energy, making it particularly useful for applications such as emergency exit signs and watch illumination. In recent years, many applications that utilize radioactive materials have been replaced by photoluminescent materials. The book explores the scientific foundations and practical applications of this technology, providing valuable insights into developments in the field of lighting technology.