Development of cryogenic permanent undulators operating around liquid nitrogen temperature

The cryogenic permanent magnet undulator (CPMU) is an insertion device in which permanent magnets (PMs) are cooled to a cryogenic temperature to improve magnetic performances in terms of remanence and coercivity. Operation of CPMUs is expected to be much easier than that of existing superconductive undulators (SCUs) with low-temperature superconducting coils, since the operating temperature can be much higher than that of liquid helium. In addition to pure PMs, high-permeability pole pieces and/or high-temperature superconductors (HTSCs) can be exploited to enhance the magnetic field of the CPMU. Towards realization of this concept, a number of R&Ds are in progress at SPring-8: field measurement under a cryogenic environment and reinforcement of HTSC samples. Encouraging results have been obtained from preliminary studies.

[1]  Masato Murakami,et al.  High-temperature superconductor bulk magnets that can trap magnetic fields of over 17 tesla at 29 K , 2003, Nature.

[2]  T. Hara,et al.  In-vacuum undulators of SPring-8. , 1998, Journal of synchrotron radiation.

[3]  T. Seike,et al.  Application of high-temperature superconducting permanent magnets to synchrotron radiation sources , 2004 .

[4]  H. Ikuta,et al.  Melt-processing of Ag-added LRE–Ba–Cu–O (LRE=Nd, Sm) , 1998 .

[5]  Hisao Yamamoto,et al.  Permanent magnet materials based on the rare earth-iron-boron tetragonal compounds , 1984 .

[6]  N. Sakai,et al.  RAPID COMMUNICATION: Levitation of NEG-123 at the temperature of liquid oxygen (90.2 K) , 2003 .

[7]  H. Kitamura.  Recent trends of insertion-device technology for X-ray sources. , 2000, Journal of synchrotron radiation.

[8]  S. Nariki,et al.  Fabrication of large melt-textured GdBaCuO superconductor with Ag addition , 2000 .

[9]  T. Seike,et al.  Cryogenic permanent magnet undulators , 2004 .

[10]  Dong Eon Kim,et al.  Demagnetization of undulator magnets irradiated high energy electrons , 2001 .

[11]  D. Krischel,et al.  Superconductive Mini-Gap Undulators - A New Way To High Energy Photons: Latest News , 2004 .

[12]  T. Bizen,et al.  Utilization of bulk high-temperature superconductors for shorter-period synchrotron radiation sources , 2006 .

[13]  M. Lemonnier,et al.  Design of an undulator for A.C.O. and its possible use as free electron la ser , 1980 .

[14]  M. Murakami,et al.  Effect of resin impregnation on trapped field and levitation force of large-grain bulk Y–Ba–Cu–O superconductors , 2001 .

[15]  R. Rossmanith,et al.  A superconductive undulator with a period length of 3.8 mm. , 1997, Journal of synchrotron radiation.

[16]  Small-gap undulator research at the NSLS: concepts and results , 1998 .

[17]  M. Sagawa,et al.  Temperature dependence of the coercivity of sintered R17Fe83−xBx magnets (R = Pr and Nd) , 1987 .

[18]  Xiaowei Zhang,et al.  Construction of an in‐vacuum type undulator for production of undulator x rays in the 5–25 keV region , 1992 .