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Caltech Synchrotron Laboratory Records

Identifier: 10078-MS

Scope and Content of Collection

Proposals, technical notes, reports, correspondence, specifications, reprints and photos; materials relating to the Atomic Energy Commission; materials on the Rochester Conferences on Ultrahigh Energy Accelerators (1952, 1955, 1956, 1960); plus other conferences and organizations.


  • 1949-1970

Language of Materials



Collection is open for research.

Publication Rights

Copyright may not have been assigned to the California Institute of Technology Archives. All requests for permission to publish or quote from manuscripts must be submitted in writing to the Head of the Archives. Permission for publication is given on behalf of the California Institute of Technology Archives as the owner of the physical items and is not intended to include or imply permission of the copyright holder, which must also be obtained by the reader.

Biographical / Historical

In the Spring of 1949, the Institute announced plans to build a one-billion volt ("1 BeV") electron accelerator. Robert Bacher, chairman of Caltech's Physics Division, stated: "The purpose of the new accelerator will be to seek additional knowledge about the nature of the forces that hold atomic nuclei together." The new accelerator, the synchrotron, would be the most powerful machine of its type ever built. The funding of the project by the U.S. Atomic Energy Commission marked the beginning of high energy physics at Caltech.

The synchrotron was the successor to the cyclotron--developed in 1932 by E.O. Lawrence--in that it extended the voltage range of high energy accelerators by the application of new physical principles. These were developed independently in 1945 by Edwin M. McMillan at Berkeley (Caltech B.A. 1928, M.S. 1929, Ph.D. 1932) and V. Veksler in Russia. McMillan later won the Nobel Prize in Chemistry in 1951 and the Atoms for Peace Prize jointly with Veksler in 1963.

The Caltech machine went into preliminary use in the summer of 1950. By 1956 it had been modified to increase its energy level to above 1 BeV. In 1961, it reached 1.5 BeV, accelerating electrons to within a few feet per second of the speed of light. Important early experiments were conducted on K-meson photoproduction, and investigations of the electromagnetic couplings of a growing number of pion-nucleon resonances were carried out. Over the years, the program concentrated largely on studies of photoproduction processes in the available energy region.

Operation of the synchrotron ended in February, 1970. Well before this time, it had become evident that collaborative efforts in experimental work were more efficient because of the complexity of the work involved and the cost of the equipment. A user program, initiated in 1962, linked Caltech with Berkeley's Lawrence Radiation Laboratory, Brookhaven National Laboratory, the Stanford Linear Accelerator, and other universities. The user program continued to expand, as accelerators entered a "super" category in both size and cost.


3.5 linear feet (8 boxes: 6 archival boxes, 2 photo boxes)


These papers document Caltech's building of a one-billion volt (1 BeV) electron accelerator, the synchrotron. Funded by the U.S. Atomic Energy Commission, the project marked the beginning of high energy physics at Caltech. The records consist of photos, technical notes, reports, conference proceedings, and proposals to the Atomic Energy Commission.

Acquisition Information

The synchrotron papers were donated to the Caltech Archives by Professor Robert L. Walker.

Related Collections

Users of the synchrotron collection should also see:

  1. Papers of Robert F. Bacher
  2. Robert F. Bacher Oral History (1981)
  3. Papers of Lee A. DuBridge
  4. Papers of Bruce H. Rule, Supplement 1984
  5. Papers of Robert L. Walker
  6. Robert L. Walker Oral History (1997-1998)
  7. Photo Archives, Synchrotron photos
Caltech Synchrotron Laboratory Records, 1949-1970
Processed by Charlotte E. Erwin; machine-readable finding aid created by Michael C. Conkin; updated by Kevin C. Knox. (November 1989; updated August 1998, June 2000)
Description rules
Describing Archives: A Content Standard
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Repository Details

Part of the California Institute of Technology Archives and Special Collections Repository

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