• C.-H. Chang, C.K. Chan, H.-P. Chang, J.-R. Chen, P.J. Chou, C.-S. Fann, J.C. Huang, C.-S. Hwang, Y.-H. Liu, C.-S. Yang
  NSRRC, Hsinchu

The highly stable pulsed magnets are designed for injection and extraction the electron beams operation in Taiwan Photon Source. The injection to the booster at 0.15 GeV is performed with septum and kicker devices as well as the extraction from the booster at 3 GeV. There are 5 in-vacuum septum and kicker magnets used for booster injection and extraction processes. For the storage ring, an injection of the electron beam into the storage ring is performed with a septum magnet and four identical kicker magnets. All pulsed magnets are designed for injection into the 3-GeV storage ring. The kicker magnet is excited with a 4.8-μs half-sine current waveform. A prototype of kicker magnet with 0.6 m of length is made and tested for examining the field errors. The field performances of the kicker magnet are presented. All pulsed magnets are fed with special current waveform. Both pulsed magnets are considered with the goal to achieve reliable work.

• J.C. Huang, C.-H. Chang, C.-S. Hwang
  NSRRC, Hsinchu

Abstract A 3-GeV electron-storage ring with tiny emittance has been designed for the Taiwan Photon Source (TPS) that will provide one of the world's brightest synchrotron x-ray sources. Sextupole magnets for the booster ring (BR) serve to correct the chromaticity of the beam particles. As an AC power supply is generally used in a booster ring to raise beam particles to a required energy, a power supply at 3 Hz AC is used to charge the sextupole magnet, which would induce eddy currents in the vacuum chamber resulting in a magnetic multipole field. As an aspect of the magnet design, decreasing the effect of an eddy current on the homogeneity of the magnetic field, the geometry and material of the chamber must be considered. We demonstrate the effects of an eddy current on the homogeneity of a magnetic field for a vacuum chamber of various types, and we discuss the magnetic circuit and the conductor design of the booster-ring sextupole. Analysis of the multipole field and eddy-current loss were included to assure the accuracy of the magnetic circuit design.

• C.-S. Hwang, C.-H. Chang, H.-H. Chen, M.-H. Huang, J.C. Jan, C.Y. Kuo, F.-Y. Lin, C.-S. Yang
  NSRRC, Hsinchu

The accelerator lattice magnets of the Taiwan Photon Source (TPS) with energy 3 GeV have been designed for the storage and booster ring. The magnetic computation codes of TOSCA and RADIA software packages were used to design the magnet circuits of the accelerator magnets. Meanwhile, the design of a magnet circuit must take into account both the requirements of accelerator physics and practical engineering constraints. The criterion of magnet design is to keep a rise of coil temperature within 10o C and a safety margin greater than 15 %. We apply pole edge shims and end magnet chamfers to enhance the field homogeneity and to decrease multipole components, respectively. The edge shim involves a smaller magnet dimension but maintains the same quality of the field. Use of an end magnet chamfer avoids field saturation. The mechanical engineering design of the storage ring magnets has been completed and the booster ring magnets have started to be designed. The 3D Solidworks package was used to draw and design the mechanical engineering. The prototype magnets of the storage ring have been contracted out to the local company in Taiwan and will be finished before the end of 2009.

• J.C. Jan, C.-H. Chang, C.-S. Hwang, F.-Y. Lin
  NSRRC, Hsinchu

Lots of multipole magnets will be fabricated for the accelerator lattice magnets of Taiwan Photon Source (TPS) that include the storage ring magnets, booster ring magnets, and the transfer line magnets. Therefore, several precise rotating-coil measurement systems (RCS) with high speed measurement are developed to characterize the magnetic field of quadrupole (QM) and sextupole (SM) magnets. Printed circuit coil including normal-coil and bucking-coil, are applied to measure the absolute and relative values of multipole components, respectively. Normal-coils with three turns (single-layer-coil) has been previously discussed and found to have good reproducibility. Moreover, a 12-turn multi-layer-coil has been designed to characterize the booster ring multipole magnets of TPS. This study, compares the compensatory characteristics of two bucking-coils with 75/150 turns and 150/300 turns with those of normal-coil. A continuously-winding-method for bucking-coil is presented in the paper. A precision testing bench was used to test the performance of this system. This work describes the measurement system design and fabrication, and discusses the system precision and accuracy.

• C.Y. Kuo, C.-H. Chang, C.-S. Hwang
  NSRRC, Hsinchu

Bending magnets, quadrupole magnets, and sextupole magnets are the most crucial magnetic elements in the synchrotron accelerator facility or high energy accelerator collider ring. Generally, separate bending magnets, quadrupoles or sextupoles magnets are utilized to perform separate functions. However, in the lattice design of accelerator ring or a compact ring in limited space, a single multifunction magnet is used to reduce the number of magnets and ensure that the entire device fits into the available space. This work presents an approach for designing the pole profiles of a combined-function bending magnet of the dipole, quadrupole, and sextupole components. The pole profile of a combined quadrupole magnet with gradient field and sextupole field components is also discussed.

• S. Chunjarean
  SLRI, Nakhon Ratchasima
• C.-S. Hwang, J.C. Jan, F.-Y. Lin, P.H. Lin
  NSRRC, Hsinchu

Highest photon beam brightnesses are achieved in radiation from undulators. Very short period length and high fields, reached only in superconducting undulators, are desired to produce hard X-rays. In lower energy storage rings this is not enough, but radiation at higher harmonics(7th and up) are desirable. This is possible only if the undulator fields and periods are near perfect. Shimming methods as applied for room temperature permanent magnet undulators cannot be used for such superconducting magnets. The effect of field and period tolerances on higher harmonics photon beam brightnesses will be presented and limiting tolerances will be discussed. A variety of different field optimization techniques together with some measurements on test magnets will be discussed and evaluated to their usefulness as a high photon energy and high brightness radiation source.