A $\hbox{Nb}_{3}\hbox{Sn}$ -Based, Model Superconducting Helical Undulator Fabricated Using a Wind and React Process
A model helical undulator 250 mm in length, with a period of 14 mm, was designed, fabricated and tested. The helical coil was wound with multifilamentary, internal-Sn type Nba3Sn strand. The 0.7 mm OD strand was insulated with S-glass, wound onto the former, and reacted, after which the coil underwent vacuum epoxy impregnation. The beam aperture was 7 mm, the winding bore diameter was 8 mm, and the OD of the complete winding was 18 mm. The helical poles were made from 1016 low carbon steel, and projected slightly above the coil pack, with an OD of 19.06 mm. The coil Ic and the magnetic field in the bore were measured at 4.2 K in a liquid helium bath. The bore field was also measured as a function of position along the length of the undulator.
Design and Development of a Superconducting Helical Undulator for a Polarized Positron Source
A small test model superconducting helical undulator for the production of 20 MeV photons has been constructed and tested. The undulator has a period of 14 mm, a bore of approximately 4 mm and produces a magnetic flux density on-axis of 0.8 T as required by the TESLA facility. Work is now underway to modify this design to meet the requirements of the ILC positron source and to manufacture a full scale prototype. This paper details the design, construction and measurements of the small test model and the modeling work necessary to extend that design for use in the ILC
Parameters for low energy operation of CESR
We present a detailed design for operation of the Cornell Electron Storage Ring, CESR, in the energy range covering the /spl psi/ resonances and the Charm and Tau thresholds, as well as reaching to the upper Y resonances near 11 GeV. The addition of 18 m of super-ferric wiggler magnets will partially restore low energy beam emittance and damping times. Installation of superconducting quadrupoles in the interaction region and the addition of high performance superconducting RF cavities will enhance performance at all energies. Studies of optics, beam dynamics, wiggler and vacuum system performance, beam stability, and beam-beam effects confirm operation with a luminosity of 3/spl times/ 10/sup 32/ CM/sup -2/ sec/sup -1/ at 1.88 GeV.