アイテム詳細

要旨

An IR and THz FEL with a design wavelength range from 4 to 500 μm has been commissioned at the Fritz- Haber-Institut (FHI) in Berlin, Germany. Lasing at 28 MeV and a wavelength of 16 μm was achieved in February 2012 [1]. We describe the performance of the undulator built and installed at FHI by STI Optronics for use in the mid-IR range (<50 μm) and 15- to 50-MeV beam energy. The undulator was a high-field-strength wedged-pole hybrid (WPH) with 40-mm period, 2.0-m long, and minimum gap 16.5 mm. A new improvement was including radiation resistance in the magnetic design. We will discuss the measured magnetic and mechanical performance, central and zero steering/offset end-field magnetic designs, key features of the mechanical design and gap adjustment system, genetic shimming algorithms, and control system.