A nuclear emulsion plate
is a photographic plate
with a particularly thick emulsion layer and with a very uniform grain size. Nuclear emulsions can be used to record and investigate fast charged particles like nucleons
. After exposing and developing the plate, single particle tracks can be observed and measured using a microscope.
In 1937, Marietta Blau and Hertha Wambacher discovered nuclear disintegration stars due to spallation in nuclear emulsions that had been exposed to cosmic radiation at a height of 2300 m (7500 feet) above sea level.
Using nuclear emulsions exposed on high mountains, Cecil Frank Powell and coworkers discovered the pion in 1947.
- J. Thewlis (ed.), Encyclopedic Dictionary of Physics, Pergamon Press, Oxford, 1962
- Robert Rosner, Brigitte Strohmaier (ed.): Marietta Blau, Stars of Disintegration. A biography of a pioneer of modern particle physics. Böhlau, Vienna 2003, ISBN 3205-77088-9 (in German)