| Abstract: | Coherent synchrotron radiation (CSR) is now an established source of radiation in the terahertz region, with flux capabilities many orders of magnitude higher than conventional SR sources. Accordingly, CSR is playing an ever-increasing role in the field of Far-IR spectroscopy at synchrotron facilities around the world. However, with the improvement in spectroscopic resolution, the incident CSR spectra from several facilities are displaying intensity profiles that appear to be modulated by periodic peaks or deep indentations, while theory predicts a featureless distribution. After eliminating the usual suspects, like multiple reflections from windows, etc., one looks for a deeper explanation, such as the role played by the radiation impedance. This impedance is largely defined by the vacuum chamber in the region of the bend magnets, but probably with some effects from the straight sections as well. |
