Signedunsigned
FunctionRegarding the cloud chamber: a video explanation and demonstration of a cloud chamber's function and operation by the Fondazione Scienza e Tecnica in Florence is available on Youtube here.
Historical AttributesAround 1934, physicist Jabez Curry Street had a homely, clapboard shed built for his research on cosmic rays. He declined space in the robust physics labs next door, because he feared that cosmic rays would not penetrate the bricks and mortar as well. His lab was called the Cosmic Ray Shed. It was considered part of the Research Laboratory of Physics (built in 1931 and renamed the Lyman Laboratory in 1947).
Street installed a cloud chamber with absorbing metal sheets, an electromagnet, and other apparatus to study cosmic ray showers. Observations by Street and Edward C. Stevenson showed that the most penetrating rays were not electrons but previously unknown positive and negative particles, which behaved in accordance with quantum mechanics. In 1937, Street and Stevenson deduced the mass of one new particle–the muon–from a photograph of its curved track in the cloud chamber.
In 1940, Street joined the war effort at MIT's Radiation Laboratory. In November 1945, he offered the use of his Cosmic Ray Shed to Edward Purcell, Robert Pound, and Henry Torrey for their experiments. It was in the shed that Pound, Purcell, and Torrey first observed nuclear magnetic resonance in a solid on 15 December 1945.
As Purcell's graduate student in early 1946, Nicolaas Bloembergen continued the experiments on NMR with Street's large cosmic ray magnet. Within a couple of months, Bloembergen, Purcell, and Pound got their own equipment going in the basement of Lyman Lab.
The cloud chamber (1998-1-0050) and the second electromagnet used for NMR (HA0111) survive in the Collection of HIstorical Scientific Instruments. Street's original cosmic ray magnet is not part of CHSI.