Search

Accurate magnetic field measurements are a prerequisite for the characterization and optimization of undulators. At the synchrotron light source ANKA there is an ongoing R&D program for superconducting insertion devices. Within this program a test stand for precise magnetic field measurements of superconductive coils was designed, built and installed at the Research Center Karlsruhe. Comprehensive magnetic measurements are performed to confirm the magnet design and to detect or correct field imperfections resulting from the manufacturing process. The magnetic field is measured along a fixed direction by Hall probes with a positioning precision of 3 μm. A NbTi undulator prototype with local correction coils was built to verify the performance of the superconductor and the shimming concept. In this contribution we describe the measuring test station and preliminary tests results including the efficiency of the shimming concept. [ABSTRACT FROM AUTHOR]

Superconducting insertion devices are very attractive for synchrotron light sources. For a given gap and period length, higher fields can be reached in respect to permanent magnet insertion devices thus permitting to reach higher photon fluxes. A new R&D program has been recently launched at ANKA aiming for the development of the next generation superconducting insertion devices for light sources. A cold bore superconducting undulator (14 mm period length, 100 full periods long) is installed in the ANKA storage ring since three years. This will be replaced by an improved version which shows a more efficient cooling system and a high precision design aiming for reduced field errors. Two additional devices are scheduled. One will allow to' electrically switch the period length between 15 mm and 45 mm corresponding to an undulator and a wiggler mode, respectively. The other will be optimized for third generation light sources. It will be capable of tolerating higher beam heat loads up to 6 W while achieving very small field errors. The field error minimization will be obtained through the use of new shimming concepts which will correct inaccuracies due to manufacturing tolerances. This paper describes the technical concepts of the three projects. [ABSTRACT FROM AUTHOR]

In March 2005 a superconducting cold-bore undulator was installed in ANKA (ANSTROEM SOURCE IN KARLSRUHE) and since that time has been in operation. The purpose of the installation was to evaluate if such a device can be operated in a heavy duty synchrotron radiation user facility like ANKA without problems. In order to demonstrate this the generated spectra were measured and the heat load induced by the beam was investigated. It was shown that the heat deposited by the beam in the 8 mm gap is less than 1 W per 100 mA at 2.5 GeV and can be cooled by cryocoolers. Finally, reference is made to the spectra produced by sub-picosecond X-rays using a special ANKA optics. [ABSTRACT FROM AUTHOR]

The article focuses on the first beam experimental test of a superconductive undulator (SCU14) at the Institute for Synchrotron Radiation storage ring at the Karlsruhe Research Center in Karlsruhe, Germany. SCU14 has been designed by ACCEL Instruments GmbH for nanometer beamline. The experiment has been aimed at demonstrating that the device can be operated under conventional user considerations, which will pave way towards advancement in spectroscopy.

Undulators in electron/positron accelerators are powerful sources of UV radiation and X-rays. The field-generating elements in classical undulators are either permanent magnets or electromagnets. For undulators with short periods, permanent magnets are used and the field strength (for a given period length and gap) is limited by the material properties. In this paper a novel concept is described which allows these limitations to be overcome by using an in-vacuo undulator with superconductive wires. [ABSTRACT FROM AUTHOR]

During the last few years superconductive undulators with a period length of 3.8 and 14 mm have been built. In this paper scaling laws for these novel insertion devices are presented: a simple analytic formula is derived which describes the achievable magnetic field of a superconductive undulator as a function of gap-width and period length. [Copyright &y& Elsevier]