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ABSTRACT: 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.
IEEE Transactions on Appiled Superconductivity 07/2011; · 1.04 Impact Factor
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ABSTRACT: A helical staggered undulator with a short period was designed to generate elliptically polarized photons. To enhance the helical field, cryogenic permanent-magnet blocks were added between the poles in hybrid-type staggered arrays, and a further exotic holmium pole was used in an analysis of the pure-type staggered arrays. A greater helical field strength was achieved with an optimal solenoid field. A helical staggered magnet with rotation of the poles was investigated; the stronger horizontal and vertical fields generated elliptically polarized photons over a much wider range. The spectral performance with elliptical polarization is presented. The field homogeneity and the distribution of the integral field on the transverse axis were calculated. The field performance of a helical staggered structure was examined with a three-period mock-up.
Journal of Physics Conference Series 07/2010; 234(3):032005.
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ABSTRACT: 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.
IEEE Transactions on Appiled Superconductivity 07/2008; · 1.04 Impact Factor
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ABSTRACT: The uniform field region (magnetic field roll-off) of the distributions of horizontal and vertical fields in the elliptically polarized undulator (EPU) of the APPLE-II structure is too short. Hence magnet block arrangements such as (1) the magnet block magnetized with a tilt angle, (2) a step shim of thickness 0.5 mm placed at the magnet edge, and (3) shortening the transverse dimension of the magnet block have been investigated to enlarge the uniform field region. The advantages and disadvantages of these block arrangements are discussed. The pure and hybrid structure of the EPU with an optimized end-pole design and the merit of flux as a function of varied phase have also been studied.
Particle Accelerator Conference, 2007. PAC. IEEE; 07/2007
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ABSTRACT: An in-achromatic superconducting wiggler (IASW) was successfully constructed and installed at the Taiwan Light Source (TLS) in January 2006. The cryostat with a 30 L liquid nitrogen aluminum reservoir shielding surrounds the helium vessel, which comprises the cold mass and 100 L liquid helium. The helium vessel is suspended by eight suspension links, which are thermally intercepted at 80 K and can be adjusted by applying tension, such that the center of the cold mass does not move during cooled to 4.2 K. A three-layered stainless tube was designed to prevent the transfer port from freezing and the steam- electricity separation system is designed to supply electricity and return the helium gas to prevent freezing of the power feedthrough.
Particle Accelerator Conference, 2007. PAC. IEEE; 07/2007
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ABSTRACT: A precise rotating coil measurement system (RCS) is developed to characterize the magnetic field quality of the quadrupole (QM) and sextupole (SM) magnets in the Taiwan photon source (TPS). A measurement bench is designed to install the magnets easily and mount the rotating coil unit with high reproducibility. The fiberglass reinforced epoxy (FRP) measurement unit (F-unit) exhibits a large sag and mechanical error while it is 880 mm long. Therefore, a new graphite measurement unit (G-unit) with a printed circuit coil is adopted to reduce these errors. The rotating coil design and testing using a QM are also described.
Particle Accelerator Conference, 2007. PAC. IEEE; 07/2007
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ABSTRACT: This study describes the design and testing of a superconducting solenoid magnet for soft X-ray magnetic circular dichroism (SXMCD) experiments at the National Synchrotron Radiation Research Center (NSRRC). The superconducting solenoid magnet provides an uniform field of up to 8 T in a bore of 55 mm in diameter and 0.5 m long. The superconducting solenoid is operated in a 4.5-K liquid helium bath for reducing the vibration level during the experiments. The magnet and its cryostat are optimized to prevent magnet quenching and lower liquid helium consumption. The magnet quench test and magnetic field measurements are also performed.
IEEE Transactions on Appiled Superconductivity 07/2007; · 1.04 Impact Factor
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C.S. Hwang,
B. Wang,
B. Wahrer,
C. Taylor,
C. Chen,
T. Juang,
F.Y. Lin,
J.C. Jan, C.H. Chang,
H.H. Chen,
M.H. Huang,
K.T. Hsu,
G.Y. Hsiung
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ABSTRACT: 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.
IEEE Transactions on Appiled Superconductivity 07/2007; · 1.04 Impact Factor
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ABSTRACT: Different from traditional detection methods which were expensive and time consuming for biochemical analyses, a DNA chip assay by using gold nanoparticles (AuNPs) immunological amplification methods and radio frequency techniques was applied to detect DNA sequences rapidly and conveniently. First the capture DNA (cDNA) was immobilized to the substrate on which the LC shunt located. Then the target DNA (tDNA) and probe DNA (pDNA) with AuNP at the 3' end were added to form AuNP-linking structures. Furthermore, the S11 and S21 curves of the biosensors changed due to the AuNP-linking structures between the interdigital and meander waveguides. The changes in S11 and S21 determined whether the tDNA existed. Due to the dual-mode design of the DNA sensors, this platform has a potential for multi-sample detection. The study provided an alternatively simple, fast and convenient solution for biochemical detection.
Nano/Micro Engineered and Molecular Systems, 2007. NEMS '07. 2nd IEEE International Conference on; 02/2007
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ABSTRACT: A mini‐pole superconducting undulator with a 15mm period length (SU15) was developed at the National Synchrotron Radiation Research Center (NSRRC). The coil was wound by a superconducting (SC) NbTi wire with small dimensions and low Cu/SC ratio. The design field strength of SU15 with 158turns/pole was 1.4T at 215A, and the magnet gap was 5.6 mm. Extra trim coils and poles are mounted on the main iron pole. The trim coils directly compensate for the strength error of the peak field. The prototype racetrack iron pole was fabricated via electric discharge machining to produce a complete set of 40‐poles. The coil was impregnated by epoxy and wrapped in Kapton to maintain insulation between coil and iron pole. A substitution beam duct was built and assembled with the magnet array and tested in the test Dewar. The conceptual design of bath liquid helium (LHe) cryostat has to tolerate more image current and radiation heating on the beam duct. © 2007 American Institute of Physics
AIP Conference Proceedings. 01/2007; 879(1):371-375.
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ABSTRACT: A mini-pole planar vertically-wound racetrack coil undulator was studied to determine its potential for use as a hard X-ray source in a 3 GeV storage ring. A field strength of 1.4 T can be obtained for a superconducting undulator with a periodic length of 1.5 cm and a fixed magnetic gap of 5.6 mm. The magnetic circuit was optimized and a current density of 1090 A/mm<sup>2</sup>, at 80% of the critical current, meets the field strength requirement. A prototype with 40 poles was constructed to verify the design of the magnet and the performance of NbTi superconductor. Additionally, the magnetic field shimming method was developed for spectrum shimming. This study discusses the design of the magnetic circuit and the structure of the magnetic array, the field shimming technique, and the test results of the prototype magnet
IEEE Transactions on Appiled Superconductivity 07/2006; · 1.04 Impact Factor
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C.H. Chang,
C.S. Hwang,
H.H. Chen,
F.Y. Lin,
M.H. Huang,
T.C. Fan,
J.C. Jan,
C.C. Chang,
S.N. Hsu,
G.Y. Hsiung,
J.R. Chen
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ABSTRACT: A 0.96 m with 16 poles superconducting wiggler is fabricated in-house at NSRRC. The wiggler produced a magnetic field of 3.1 T for a 61 mm period with a pole gap of 19 mm. Three 5-pole prototype magnets using various pole materials from low carbon steel, vanadium permendure steel and holmium are tested and measured to verify the magnetic field performance in the testing dewar. This work describes the design and construction of a magnet and cryostat system. Furthermore, this work presents the results of magnet tests and the field performance of the compact superconducting wiggler
IEEE Transactions on Appiled Superconductivity 07/2006; · 1.04 Impact Factor
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ABSTRACT: To provide wide horizontal aperture of kicker ceramic chamber at the downstream of a short insertion devices and prepare for the operation of top-up mode injection, the National Synchrotron Radiation Research Center (NSRRC) has upgraded the kicker systems. The new systems have been tested and installed. An efficient procedure of in-situ wave form tuning was proposed and tested successfully.
Particle Accelerator Conference, 2005. PAC 2005. Proceedings of the; 06/2005
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ABSTRACT: The National Synchrotron Radiation Research Center (NSRRC) at Taiwan is designing a 3 GeV energy with ultra-low emittance storage ring for the new Taiwan Photon Source (TPS). The storage ring has a circumference of 514 m with 24 periods of a double-bend achromatic magnet system. The conceptual designs of each magnet family to be used in the storage ring are optimized for operation at an electronic energy of 3.0 GeV. This investigation reviews the preliminary design and the core issue related to the accelerator magnet.
Particle Accelerator Conference, 2005. PAC 2005. Proceedings of the; 06/2005
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C.S. Hwang, C.H. Chang,
H.P. Chang,
C.K. Chang,
J.R. Chen,
H.H. Chen,
J. Chen,
Y.C. Chein,
T.C. Fan,
C.C. Kuo,
F.Y. Lin,
K.T. Hsu,
S.N. Hsu,
M.H. Huang,
G.Y. Hsiung,
C.T. Chen
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ABSTRACT: Two superconducting magnets, one wavelength shifter with a field of 6 T and one wiggler with a field of 3.2 T, were constructed and routinely operated at Taiwan Light Source to generate synchrotron X-rays. Additionally, three short multipole wigglers with the same field of 3.1 T are under construction and will be installed in the three achromatic short straight sections. A warm beam duct with an inner gap of 20 mm and a 1.5 W GM type cryo-cooler were used in the wavelength shifter to achieve cryogen-free operation. For the 3.2 T wiggler, a cold beam duct with an inner gap of 11 mm was kept at 100 K temperature and no trim coil compensation is necessary for its operation. Meanwhile, no beam loss was observed when it was quenched. The design concept, magnetic field quality, and the commissioning results of these magnets will be presented.
Particle Accelerator Conference, 2005. PAC 2005. Proceedings of the; 06/2005
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C. S. Hwang,
B. Wang,
J. Y. Chen, C. H. Chang,
H. H. Chen,
T. C. Fan,
F. Y. Lin,
M. H. Huang,
C. C. Chang,
S. N. Hsu,
G. Y. Hsiung,
K. T. Hsu,
J. Chen,
Y. C. Chien,
J. R. Chen,
C. T. Chen
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ABSTRACT: A 3.2 Tesla superconducting multipole wiggler was designed and fabricated as an X‐ray source. The magnet assembly, which consists of 32 pairs of racetrack NbTi superconducting coils with a periodic length of 60 mm, provides 28 effective poles. A 1.4056 m long elliptical cold‐bore stainless steel beam duct with taper flanges and a wall thickness of 1 mm, was developed and constructed to fit the ultra‐high vacuum condition for electron beam. The magnetic field strength was measured in liquid helium using a cryogenic Hall probe, revealing a field behavior very close to behavior consistent with the designed values. A Hall generator and the stretch wire methods are used to determine the transfer function of the peak field, the first and second integrated field distributions, and the good field region of the magnet. The quench protection of the magnet, the control algorithm for automatic filling of liquid helium, and the boil off rate of liquid helium and liquid nitrogen will also be discussed. © 2004 American Institute of Physics
AIP Conference Proceedings. 05/2004; 705(1):199-202.
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ABSTRACT: We have constructed and commissioned an infrared beamline mainly for high spatial resolution microanalysis by FTIR microscopy. This beamline collects 70 × 35 mrad radiation fan and covers a wavelength range from 2 to 30 μm which provides an optimal performance capability down to 400 1/cm (25 microns). The optics consists of one water‐cooled plane mirror, two high‐order polynomial bendable focusing mirrors, and one set of steering and collimating mirrors. Two high‐order bendable polynomial mirrors are designed and constructed to effectively collect and focus the 70 mrad extended arc radiation source onto a focal point. To achieve high mechanical stability, the photon beam is reflected downwards 90 degrees by the first mirror and the mirror holder is attached to the massive bending magnet girder. The high stability of mirror manipulators and supporters, has been confirmed by the vibrational measurement with accelerometers during the beamline operation. The brightness of the infrared spectrum has been measured and compared to a standard thermal source with different pinhole sizes, exhibiting values to be greater than that of standard thermal source when the pinhole is set at < 30 um. The signal to noise (S/N) ratio measured in the mid infrared region is about 500 times greater than that obtained from a blackbody source when the pinhole size is < 10 um. In this report we will present the performance of this infrared beamline and the high spatial resolution data by FTIR microscopy. © 2004 American Institute of Physics
AIP Conference Proceedings. 05/2004; 705(1):478-481.
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ABSTRACT: A 32-pole superconducting magnet with a 12 × 80 mm<sup>2</sup> cold bore aperture was designed to serve as a multipole wiggler in the Taiwan synchrotron light source. The magnet consists of 32 pairs of racetrack NbTi superconducting coils with a periodic length of 60 mm, and can produce a maximum magnetic field of 3.2 Tesla at a pole gap of 18 mm. The superconducting coils, the aluminum-supporting block, and the return iron yokes are cooled to 4.4 K in LHe bath. The temperature of cold bore beam duct will be at 70 K using liquid nitrogen. Technical issues concerning the design of the magnet and its construction are discussed. A prototype magnet with five poles was also constructed to characterize the magnet design by means of various methods of magnetic field measurement.
IEEE Transactions on Appiled Superconductivity 07/2003; · 1.04 Impact Factor
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ABSTRACT: The first superconducting multipole wiggler with period length of 6.0 cm (SMPW6) of the National Synchrotron Radiation Research Center (NSRRC) is currently under construction. SMPW6 will be tested and installed at the RF cavity section of storage ring by the autumn of 2003. For quality control, the magnetic field is checked at three main phases according to the assembly process. To operate the field measurement in a narrow duct and at different temperature of duct at different phases, three small-gap measurement systems were specially designed. Not only the centerline field can be measured point-by-point but also the multi-pole field can be mapped. All the measurement systems have been carefully tested. The consideration of the measurement systems and preliminary measurement are shown in this paper.
Particle Accelerator Conference, 2003. PAC 2003. Proceedings of the; 06/2003
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ABSTRACT: Since 1995, we have continuously installed five insertion devices (IDs) in the 1.5 GeV storage ring TLS at NSRRC. They include three undulators (U5, U9 and EPU5.6), one 1.8 Tesla wiggler (W20) and one 6 Tesla superconducting wavelength shifter (SWLS). All these five IDs are located in the long straight sections. The real time orbit correction and betatron tune compensation routine have been successfully operated. With these IDs, the machine emittance reduces substantially. We plan to install four more superconducting multi-pole wigglers (SMPWs), one in the long straight and three in the archromat sections. These devices therefore can offer more beam time for the hard X-ray community. The impacts of these IDs on the beam dynamics effects are reported in this paper.
Particle Accelerator Conference, 2003. PAC 2003. Proceedings of the; 06/2003
