Ionizing radiation through the photoelectric effect and the Compton effect. Either of those interactions will cause the ejection of an electron from an atom at relativistic speeds, turning that electron into a beta particle (secondary beta particle) that will ionize many other atoms. Since most of the affected atoms are ionized directly by the secondary beta particles, photons are called indirectly ionizing radiation. Photon radiation is called gamma rays if produced by a nuclear reaction, subatomic particle decay, or radioactive decay within the nucleus. It is otherwise called x-rays if produced outside the nucleus. The generic term photon is therefore used to
The Racah Institute of Physics first nuclear experimentalist measuring very long lived radionuclides as well as extremely short lived nuclear states. In the early sixties his interests shifted to the newly discovered Mossbauer effect, and established a research group which turned Jerusalem into a world center in this field. Many graduates of the Racah Institute (and the physics departments which preceded it) became leading professors and scientists (including a Nobel Laureate) in Israel and all over the world. During its existence the Institute enjoyed visits of many important physicists from all over the world. Niels Bohr, Paul Dirac, Wolfgang Pauli, Robert Oppenheimer, John Wheeler and