SRF Challenges for Energy Recovery Linacs

Many of the challenges associated with operating a Superconducting RF SRF Energy Recovery Linac ERL are independent of the choice of operating frequency, beam energy, and overall purpose of the machine. Worldwide there are an increasing number of ERLs in various stages of development and operation which are facing a number of similar challenges and often solving them in very different ways. This paper will seek to summarize the main challenges the community as a whole faces, address how different laboratories are working to solve these problems, and seek to identify areas of overlap where the community can work together to solve some of these common problem