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A 3-pole gradient-damping wiggler (GDW) was developed for the ALPHA storage ring at Indiana University. The GDW is effective in modifying the momentum-compaction factor and the damping partition number in the ALPHA storage ring. The yokes of GDW are made by lamination of silicon steel sheets (50CS1300) with a thickness 0.5 mm. Glue (3M 2216) is used to paste the lamination sheets together to create a block using a punch fixture. The C-shape structure and the pole profile of the damping wigglers are cut from the silicon-steel blocks with the wire-cutting machine. One middle pole and two outer poles are assembled on the same girder as the set of GDW. The oblique of pole profile of middle and outer poles is different to obtain the same polarity of gradient field. The magnet gaps of the middle and outer poles are 40 and 35.87 mm; respectively to obtain the same dipole field strength. The field strengths of dipole and gradient-field of the middle (outer) pole are 0.67 T (-0.67 T) and 1.273 T/m (1.273 T/m), by keeping the integral ratio of (dB/dx)/B=1.9\ m^-1 constant. The three combined functions of the dipole magnet can be charged in 1 Hz with a single power supply. There are trim coils on the three poles to adjust the first and second integral fields to zero. The good field region of the middle and outer poles along the transverse x-axis (\DeltaB/B=0.1\%) are \pm50 and \pm40 mm respectively. After fabrication of one set GDW magnet, a Hall probe measurement system was used to measure the magnetic field to verify the design and construction performance of the magnet. [ABSTRACT FROM PUBLISHER]

This paper presents the design of magnets for the storage ring of the 3-GeV Taiwan Photon Source project. Detailed calculations of the field were performed according to a three-dimensional model, and the magnetic geometry was determined in transverse and longitudinal planes to conform to highly precise magnetic fields. The final tolerances of the pole profiles of the magnets within 20 \mum were manufactured and measured in all prototype magnets. The characteristics of the magnetic fields were measured with Hall-probe and rotating-coil systems to verify the quality of the magnetic fields. The centers of the magnets will be aligned on the girder with precisely machined rails within 20 \mum, and the magnets have no provision for shimming on the girder. The features of the main field and homogeneity of these magnets are described and analysed to reveal the satisfactory magnetic performance. [ABSTRACT FROM PUBLISHER]

The use of HTS (high-temperature superconductor) coils for accelerator magnets decreases significantly the power consumption and operating cost. Therefore, a preliminary study was launched and a prototype of a dipole magnet with HTS coils has been designed and fabricated by NSRRC and HTS-110 Ltd. Although 2G YBCO wire is expected to be used in future HTS applications, it currently requires more joints to form the completed coils. For this reason, we chose 1G BSCCO wires for the HTS coils. Two single-stage pulse-tube refrigerators with one compressor serve to cool the HTS coils of the magnet, but we shall use LN2 to replace the pulse-tube refrigerators in the future. The HTS magnet is designed to provide a stable field of strength 1.19 T with field homogeneity better than 1.5\times 10^-4 in the range of the transverse direction -20\leq x\leq 20\ mm when it operates at 50 K with a current of 110 A. To compare with the field features of copper-coil dipole magnets, a Hall-probe measurement system was used to measure the detailed magnetic field and B-I characteristics of the HTS dipole magnet at NSRRC. [ABSTRACT FROM PUBLISHER]

A 130-pole superconducting undulator with NbTi wires was wound and tested at National Synchrotron Radiation Research Center (NSRRC). The magnetic field was measured with a cryogenic mini-Hall sensor in a vertical dewar. The difference of total length between the nominal design and that measured experimentally with the Hall probe is approximately 1.2 mm; this discrepancy arises from the thermal contribution during the field measurement in the test dewar. The reliability of the measurement system is confirmed, and is discussed in terms of the field-mapping spectrum. The measurement of the field strength revealed a non-uniform distribution of the field in the 1 m long arrays. An iron pole piece was used to shim the on-axis field strength of the undulators. We discuss the thermal effect of the measurement system, a useful shimming method and its results for the superconducting undulator. [ABSTRACT FROM AUTHOR]

A prototype of an Apple-II elliptically polarized undulator (EPU4.6), of length 0.46 m, has been constructed to test the performance of the newly designed magnet block, which was magnetized at a tilt angle 10°. The magnet design and various mechanism analysis are performed to clarify the error source of multipole field components. Good end pole design in the EPU4.6 revealed the variation of the first integral field strength as function of gap and phase is minimized. Shimming algorithm had been used to improve the field quality and phase error. We report here the scheme of the magnetized block arrangement, an analysis of the design mechanism, the end pole design, field shimming and the final test performance using the Hall-probe mapping system. [ABSTRACT FROM AUTHOR]

A compact three-pole superconducting magnet with an aluminum warm beam duct was designed and fabricated as an X-ray source in a 1.5 GeV Taiwan Light Source (TLS) or the 3 GeV Taiwan Photon Source (TPS). Three pairs of racetrack NbTi superconducting coils were connected to one main power supply to create a central field of over 6.5 T. Two low current trim power supplies were connected in parallel to the two side pairs of the coil to eliminate the first and second field integrals. The wavelength shifter magnet was cooled in a pool boiling helium bath. Helium boils off at 1.3 L/hr. The vapor-cooled current lead is used to pass the 350 A excitation current. The magnetic field strength was measured at room temperature using a Hall probe and a stretched wire system. The magnet was tested successfully to 308 A, at which the central field exceeded 6.5 T, and the peak field on coil was 8.2 T. The design and construction of the magnet and the cryostat, the quenching protection, and field measurement results will be presented and discussed. [ABSTRACT FROM AUTHOR]

Pulsed magnets were characterized for use for injection in the top-up mode for Taiwan Photon Source (TPS). Two kicker magnets in vacuum were implemented to inject and to extract electron beams for the booster ring. Five septum and four kicker magnets of in-air type were provided for injection into a 3-GeV storage ring. All pulsed magnets are of home design, manufactured and assembled in National Synchrotron Radiation Research Center. To verify the quality of a magnetic field and its distribution, measurement systems including long-coil and search-coil systems were installed. The pulsed power supply was improved to gain exact stability. We report that through our shielding design, the maximum leakage field of the septum along the beam trajectory is less than 0.02% of the main field. [ABSTRACT FROM PUBLISHER]

Taiwan Photon Source (TPS) is a synchrotron radiation facility of medium energy, 3 GeV, and low emittance, under construction at National Synchrotron Radiation Research Center (NSRRC). The multipole errors of lattice magnets were rigorously examined and corrected so as to maintain the dynamic aperture of the electron beam in the storage ring. The lattice magnets were fully inspected at both the vendor and vendee sites. The multipole errors of the lattice magnets were tested and corrected. In particular, the sextupole magnets have the pole position adjusted to correct the multipole errors so as to conform to the specification. The yoke cutting is to correct the octupole error of the long-quadrupole magnets. The shimming of the magnetic center and the final examination of the magnets will be undertaken at NSRRC. In this paper, we report the methods of correcting the multipole errors, the magnetic center, and the performance of the TPS lattice magnets. [ABSTRACT FROM PUBLISHER]

Taiwan Photon Source (TPS) is a low-emittance synchrotron radiation factory. The lattice magnets are located compactly within the limited space in the storage ring. The mutual proximity of the magnets induces field crosstalk and influences the dynamic aperture of the electron beam. The field becomes distorted, induced by the crosstalk within not only the iron yoke but also the edges of the magnets. Precise measurements with rotating-coil systems were conducted to characterize the integral field quality of the magnets; a new method to detect the center of magnets is presented. Simulation with TOSCA software was undertaken for comparison with these experimental results. We report the field distortions induced by crosstalk on the basis of our measurements and simulations. A misalignment effect between the quadrupole and sextupole magnets is discussed. [ABSTRACT FROM PUBLISHER]

The septum magnet bends the injection beam before the kicker magnet. The septum magnet is located near the storage ring in the Taiwan Photon Source (TPS). As the space from the magnet wall to the vacuum chamber of the ring is less than 3 mm, the leakage field of the septum magnet thus influences the stability of the electron beam in the storage ring. The main field and the leakage field of a septum of the direct-drive type are compared to one of the eddy-current type. The effects of the vacuum chamber and \mu-metal are simulated with full-sine and half-sine current pulses with the OPERA-2D TR analysis module; measurement results are presented in this paper. [ABSTRACT FROM PUBLISHER]