TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
CLASSE, Ithaca, New York, USA
Muons, Inc, Batavia, USA
CLASSE, Ithaca, New York, USA
SLAC, Menlo Park, California, USA
Superconducting RF (SRF) systems typically contain resonances at unwanted frequencies, or higher order modes (HOM). For storage ring and linac applications, these higher modes must be damped by absorbing them in ferrite and other lossy ceramic materials. Typically, these absorbers are brazed to substrates that are often located in the drift tubes adjacent to the SRF cavity. These HOM absorbers must have broadband microwave loss characteristics and must be thermally and mechanically robust, but the ferrites and their attachments are weak under tensile and thermal stresses and tend to crack. Based on prior work on HOM loads for high current storage rings and for an ERL injector cryomodule, a HOM absorber with improved materials and design is being developed for high-gradient SRF systems. This work will use novel construction techniques (without brazing) to maintain the ferrite in mechanical compression. Attachment techniques to the metal substrates will include process techniques for fully-compressed ferrite rings. Prototype structures will be fabricated and tested for mechanical strength under thermal cycling conditions.
HZB, Berlin, Germany
CLASSE, Ithaca, New York, USA
Hard x-ray Energy Recovery Linacs (ERLs) operate with high-brightness electron beams, matching the requirements for X-ray FELs in terms of emittance and energy spread. We have analyzed in how far it is feasible to include X-ray FELs in ERL facilities. X-ray FEL Oscillators require comparatively low peak currents and are therefore good candidates for FEL sources in ERLs. However, also high-gain FELs do not seem out of reach when bunch-compression schemes for higher peak currents are utilized. Using the proposed Cornell ERL as an example, different FEL concepts are discussed and their suitability as X-ray sources are analyzed.
CLASSE, Ithaca, New York, USA
CLASSE, Ithaca, New York, USA
Cornell University, Ithaca, New York, USA
Energy Recovery Linacs (ERLs) are proposed as drivers for hard X-ray sources because of their ability to produce electron bunches with small, flexible cross sections and short lengths at high repetition rates. The advantages of ERL lightsources will be explained, and the status of plans for such facilities will be described. In particular, Cornell University plans to build an ERL light source, and the preparatory research for its construction will be discussed. This will include the prototype injector for high current CW ultra-low emittance beams, superconducting CW technology, the transport of low emittance beams, halo formation from intrabeam scattering, the mitigation of ion effects, the suppression of instabilities, and front to end simulations. Several of these topics could become important for other modern light source projects, such as SASE FELs, HGHG FELs, and XFELOs.