Magnet Design and Testing for the 250 MeV Injector of the SwissFEL at the Paul Scherrer Institute

• Published in: IEEE transactions on applied superconductivity 2010-06, Vol.20 (3), p.265-269
• Main Authors: Sanfilippo, S, Negrazus, M, Vrankovic, V, Sidorov, S, Gabard, A, Glowa, N H, Kim, Y J, Ganter, R, Pedrozzi, M, Braun, H
• Format: Article
• Language: English
• Subjects: Acceleration; Applied sciences; Beams (radiation); Brightness; Design engineering; Dipole; Electrical engineering. Electrical power engineering; Electromagnetism; electron and ion optics; Electromagnets; Electron accelerators; Electron emission; Electron sources; Electronics; Electrostatic, collective, and linear accelerators; Exact sciences and technology; Experimental methods and instrumentation for elementary-particle and nuclear physics; field quality; Free electron lasers; Fundamental areas of phenomenology (including applications); Imaging devices; Injectors; Lasers; Linear accelerators; Magnetic field measurement; Nuclear physics; Physics; Preserves; quadrupole; R&D; Radiation by moving charges; Research & development; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Solenoids; synchrotron source; Testing; Various equipment and components; X-ray lasers
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/TASC.2010.2043828

The Paul Scherrer Institute (PSI/Switzerland) is planning an X-ray free electron laser facility (SwissFEL) using novel concepts for electron emission, high gradient acceleration and effective bunch compression. Based on a normal-conducting 5.8 GeV linear accelerator, SwissFEL will cover a spectral range of 0.1-7 nm wavelength. An ultra bright electron source was first developed and commissioned in 2008 followed by the construction of a 250 MeV accelerator facility in order to validate the concepts to generate and transport high brightness beams. This facility will be used in the future as the injector for the SwissFEL linac. An amount of typically 100 magnets of 4 different types (solenoids, quadrupoles, dipoles and correctors) is required in order to preserve the high brightness and the low emittance of the femto-second electron pulses. All the magnets are designed and magnetically measured at PSI in order to ensure that the required tolerances are fulfilled. The field gradient, the multipole contents and the magnetic center position are measured with two independent systems, an automated scanner and a uniaxial Hall Probe. We review the magnet design required for the injection phase and discuss the first results of the magnetic measurements.