On the " Circular Vacuum Noise " in Electron Storage Rings

We discuss the proposal of Bell and Leinaas (BL) to measure the circular Unruh effect in storage rings. The ideal concept ‘circular Unruh effect’ has a more realistic correspondent such as ‘circular vacuum noise’ used by Shin Takagi [Prog. Theor. Phys. Suppl. 88, 1 (1986)] The BL resonance behavior does not fit to the SPEAR first order betatron resonance at 3.605 GeV, but of course, the real experimental situation is much more complicated, corresponding, as a matter of fact, to an even more general term that one may call ‘synchrotron noise’. In the final section we focus on radiometric aspects of storage ring physics, such as the problem of establishing better quantum field radiometric standards at high energies. The Unruh-like effect could be a useful guide for that purpose. PACS numbers: 29.20.Dh, 04.20Cv, 07.60.Dg