June 17, 2005  


SSRL Celebrates 25 Years of Pioneering Insertion Devices

By Herman Winick

Twenty five years ago the first permanent magnet undulator to be used for synchrotron radiation research was implemented at SSRL, in collaboration with LBNL. A year earlier the first electromagnet wiggler, designed by Jim Spencer, was implemented at SSRL. These two pioneering insertion devices started the revolution in synchrotron radiation sources and research.

Pioneers gather in front of the first permanent undulator magnet display. From left to right are Richard Boyce (ASD), John Yang (ESRD, retired), Herman Winick (SSRL), Egon Hoyer (LBNL, retired), and John Chin (LBNL, retired).
(Photo by Topher White)

Due to the success of these devices, and similar experience at the Budker Institute in Novosibirsk, many third generation synchrotron radiation sources (storage rings optimized for such insertion devices rather than merely using radiation from the ring bending magnets) were built starting in the late 1980ís. The latest of these is the SPEAR3 storage ring at SLAC.

To mark this 25th anniversary, some of those who contributed to the design, construction and characterization of the spectrum for the first permanent magnet undulator gathered around the magnet itself, which is on display on the SSRL experimental floor. The concept for this magnet was the brainchild of Klaus Halbach of LBNL. The mechanical design was done by LBNL engineers Egon Hoyer and John Chin, now retired.

The electronic controls for varying the gap and compensating the end fields was done by John Yang, recently retired from SSRL. The spectrum from this device was characterized by George Brown, Teresa Troxel, and Herman Winick of SSRL along with Zahid Hussain and Eberhard Umbach at LBNL.


The Stanford Linear Accelerator Center is managed by Stanford University for the US Department of Energy

Last update Tuesday June 14, 2005 by Topher White