Emission of photons by undulators

Abstract

Relativistic electrons subjected to periodic acceleration in an undulator (planar or helical) emit quasi-monochromatic synchrotron radiation, which is tunable and polarized. Such emissions have been observed previously in e(-) beams accelerated in linear accelerators or synchrotrons. Synchrotron radiation laboratories are developing undulators, which will constitute exceptional photon sources when placed on storage rings: their brightness is expected to be several orders of magnitude greater than the brightness of the same e(-) beam in normal bending magnets, and, depending upon the e(-) energy, they can be tuned from the visible to the x-ray range. Recent experiments on storage rings show that the observed emission agrees with theoretical predictions.

Observation and analysis of interferences on undulator coherent radiation stored in an optical cavity

“…It requires a production of coherent emission [6] by the electron bunch in the undulator, and this occurs when the bunch distribution contains sharp edges that are creating high-frequency components in the Fourier transform spectrum. The spontaneous emission train [14] This represents the amplitude of coherent emission produced by a bunch of electrons. Assuming the spectrum of bunch distribution e ρðνÞ is rather constant close to ν o , then the coherent emission linewidth of e…”

Photoneutron generation with electron undulators

“…The undulator therefore would have to be within the vacuum enclosure of the storage ring. That, however, is not a new problem: one design 15 allows an internal undulator to be removed during the electron-injection operation, then reinserted. or.…”

“…2 D (2223 keV). or even heavier nuclei (6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20). thereby creating an intense source of photoneutrons.…”

Induction shimming: A new shimming concept for superconductive undulators

“…A second concept consisted of replacing the permanent magnets by superconductive wires. After first experiments in the 1970's [6,7], the development was resumed in the early 1990's [8,9] and several intermediate steps were followed by the installation of a 100 period superconductive undulator with a period length of 14 mm in the storage ring ANKA in April 2005 [10,11]. This device made it possible to study the properties of the emitted radiation [12], the beam heat load [13], the effect of the undulator on the orbit [14], the field errors, and the development of correction schemes for field errors [15,16].…”