Aladdin, Fighting Back, Surpasses Performance Goals

Since the first of the year, the circulating electron beam of the Aladdin synchrotron light source at the University of Wisconsin has been surpassing 100 milliamps—its “nominal commissioning level”—and it's still getting better. This happy news must be understood in the less happy context of recent years (PHYSICS TODAY, August, page 45, and November, page 58). When construction of this roughly square electron storage ring—27 meters on a side—was begun in 1977, the goal was to achieve a stored electron beam current of at least 100 milliamps with a maximum electron energy of 1 GeV. The purpose was to provide experimenters with synchrotron light beams of adequate intensity in the spectral range from the vacuum ultraviolet up to about 4 keV in the soft-x-ray regime. This synchrotron radiation, generated as the electron beam negotiates the rounded corners of the Aladdin square, was intended eventually to be augmented by the outputs of wigglers and undulators inserted in the long straight sections of the ring.