Volz, P.I.; Grimmer, S.; Huck, M.; Meseck, A.: Goubau-Line Set Up for Bench Testing Impedance of IVUE32 Components. In: Changbum Kim ... [Ed.] : IBIC 2021 : Proceedings of the 10th International Beam Instrumentation Conference, Pohang, Korea, 13–17 September 2021Geneva, Switzerland: JACoW Publishing, 2021. - ISBN 978-3-95450-230-1, p. TUPP42/1-3
https://jacow.org/ibic2021/papers/tupp42.pdf
Open Access Version
Abstract:
IVUE32 is the world first elliptical in-vacuum undulator, being developed at HZB. With a period length of 32 mm and a minimum gap of 7 mm, the 2.5 m long insertion device (ID) will be installed in the BESSY II storage ring, delivering soft X-rays to several beam lines. In-vacuum undulators put complex structures in close proximity of the particle beam which makes them susceptible to wake field effects. These effects can cause beam instabilities and unwanted heating of undulator components, possibly damaging them. Therefore understanding the impedance characteristics of the device prior to installation is paramount. Numerical studies, e.g. CST simulations of such complex structures become very resource intensive for high frequencies, making the ability to bench test such a device invaluable. A Goubau line is a single wire transmission line for high frequency surface waves that can mimic the transverse electric field of a charged particle beam out to a certain distance, allowing for impedance measurements of IDs outside of the working accelerator. The status of a Goubau-line set up, optimized for measuring IVUE32-components, will be presented.