An experimental superconducting helical undulator

Improvements in the technology of superconducting (SC) magnets for high energy physics and recent advancements in SC materials with artificial pinning center (APC) [1], have made a bifilar helical SC device an attractive candidate for a single-pass free electron laser (FEL) [2]. Initial studies have suggested that a 6.5 mm inner diameter helical device, with a 27 mm period, can generate a central dipole field of 2–2.5 T [3]. Additional studies have also suggested that with a stored energy of 300 J/m, such a device can be made self-protecting in the event of a quench. As a first step towards the construction of 2 m long prototype we propose to build and test a small mechanical model that will serve as a proof of principle for such a high current density magnet, will assure its safety and provide dimensional parameters. In this paper we discuss technical issues relevant to the construction and protection of a single layer, low field (1.17 T), short (300 mm) experimental undulator.