Development of five compact storage rings, TERAS and NIJI-I–IV, at ETL

Abstract

At the Electrotechnical Laboratory (ETL) four compact storage rings, TERAS and NIJI-I–III, have been constructed and a compact storage ring, NIJI-IV, with 7.2 m long straight sections for a free electron laser (FEL) experiment will be completed in November 1990. TERAS is a 0.8 GeV storage ring and has been operated since October 1981 for research into radiometric standards, dissociative photoionization, SR lithography, generation of gamma-rays and FEL experiments using a transverse optical klystron (TOK). A 10 T three-pole wiggler will be installed in 1991 at the straight section where the TOK is installed. NIJI-I is a 0.27 GeV compact ring. It was operated from February 1986 to March 1989 for machine study of beam storage higher than 0.5 A at low energies below 0.15 GeV. NIJI-II is a 0.6 GeV conventional-type compact ring operated in August 1989 for SR lithography, chemical vapor deposition (CVD) and polarized SR experiments. NIJI-III is a 0.62 GeV superconducting-type ring for SR lithography operated in June 1990. Key technologies needed to realize compact SR facilities, such as the electron undulating method and high-current storage, are briefly reviewed.