overall: 10 1/4 in x 10 1/4 in x 4 1/2 in; 26.035 cm x 26.035 cm x 11.43 cm
Maser, Part of
This object, the focusing assembly from the second maser, was made at Columbia University in 1954 by a team led by physicist Charles H. Townes. Maser stands for Microwave Amplification by Stimulated Emission of Radiation. Masers operate on the same principals as lasers, but they amplify microwaves instead of light. In fact, masers came first. Microwaves have lower energy levels than light and so were easier to produce, although the maser was not a simple invention.
After working on microwave radar and other devices during the Second World War, Townes undertook investigations of microwave spectroscopy at Columbia University. Working with James Gordon and Herbert Zeigler, he successfully demonstrated an ammonia-beam maser in April 1954. The unit was quite large so Townes developed a smaller unit later that year, several pieces of which were donated to the Smithsonian in 1965.