Synchrotron Radiation from a Synchrotron
We must face reality: almost all synchrotron radiation users of today have never seen a synchrotron! As we know, what they call “synchrotrons” are really “storage rings”. Only a tiny minority of elderly, retired scientists worked at real synchrotrons – and were lucky to survive the experience. I am one of them. Indeed, the first time I used synchrotron radiation was in the 1970s at the 1.1 GeV “elettrosincrotrone” of the Frascati National Laboratory. Which in the 1970s was the source for our synchrotron radiation project “PULS”.
How was my experience? Miserable! Contrary to a storage ring, a synchrotron is a pulsed source in which electron bunches are continuously injected, accelerated and dumped. The bunches cause very dangerous radiation, so we could not work close to our experimental chamber when they travelled in the ring. This transformed simple operations into a nightmare. For example, a sample alignment that takes a few minutes at a storage ring required days or weeks — subsequent small adjustments being separated by hours of accelerator operation.
At Frascati, we were dreaming of using the excellent storage ring Adone instead of the synchrotron — but this happened only later. Personally, after months of misery I found a way out when I was hired by Bell Labs in New Jersey. Which, to my relief, was as far as possible from the synchrotron facilities of that time. But I could not escape my destiny: shortly after my arrival, Bell Labs asked me to start experiments at the Wisconsin Synchrotron Radiation Center! Fortunately, the source there was not a synchrotron but the storage ring Tantalus. I could thus appreciate the huge advantage over real synchrotrons. I am indeed convinced from experience that, without the arrival of storage rings, synchrotron radiation research would have died at birth.
Giorgio Margaritondo
Faculté des Sciences de Base, Ecole Polytechnique Fédérale de Lausanne
(EPFL), CH-1020 Lausanne, Switzerland
Image: The Frascati electron synchrotron, where my career in synchrotron radiation started and almost
ended