Marietta Blau and the photographic method of particle detection

Abstract

Marietta Blau was a Vienna born nuclear physicist who eventually became the leading expert in the photographic detection of ionizing particles. She studied physics at the University of Vienna, graduated in 1919. As of 1924, she adapted the technique of photography for the detection of nuclear particles at the Vienna Institute for Radium Research. When after years of painstaking methodical development Blau succeeded in registering tracks of particles, she and her collaborator Hertha Wambacher further refined the technique and by its use discovered the star-shaped tracks of reaction fragments from the interaction of cosmic-ray particles in photographic emulsions, the disintegration stars, in 1937. Due to her Jewish descent, Blau emigrated in 1938, first to Mexico, later to the U.S. where she had access to scientific research again in 1948. At Brookhaven National Laboratory and Miami University she applied the photographic method to reactions induced by high-energy particles from accelerating machines rather than cosmic rays. When she returned to Vienna in 1960, she supervised the evaluation of photographic plates from CERN experiments.