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Examines high power microwave generation from a tunable radially extracted vircator. Experimental apparatus and diagnostics; Details on beam and microwave measurements; Mechanisms proposed to explain the microwave emission by vircators; Information on virtual cathode, an unstable region of negative potential.

Presents a study that developed a potential flow model to examine the linear behavior of the hydromagnetic equivalent of the Rayleigh-Taylor instability in imploding cylindrical plasmas. Achievement of the ordinary differential equations; Dynamic effects of the moving plasma on the development of the instability; Growth of perturbations for imploding plasmas.

Objectives: To compare the efficacy and safety of transoral robotic surgery (TORS) with endoscope‐guided coblation tongue base resection. Design: Retrospective case‐control study. Setting: University‐based tertiary care medical center. Participants: Patients with obstructive sleep apnoea (OSA) who underwent endoscope‐guided tongue base coblation resection or transoral robotic surgery (TORS) in combination with lateral pharyngoplasty at a single institution in South Korea between April 2013 and December 2016 were investigated. Forty‐five patients who had moderate‐to‐severe OSA with tongue base collapse and a minimum follow‐up period of 6 months with postoperative polysomnography (PSG) were enrolled in this study. Main outcome measures: All patients underwent pre‐ and postoperative (at least 4 months after surgery) overnight PSG. Available information on results of the PSG, Epworth sleepiness scale and complications of the TORS and coblation groups were compared. Results: Postoperative PSG studies showed improved sleep quality for most patients. The mean postoperative apnoea‐hypopnea index (AHI) was reduced significantly from 45.0 to 17.0 events/h (P < .0001) in the TORS group and from 45.6 to 16.2 events/h (P < .0001) in the coblation group. The mean rates of improvement (AHI reduction > 50%) were 75.0% in TORS patients and 62.1% in coblation patients and the difference was not significant. Less frequent postoperative morbidity, including bleeding, taste dysfunction and foreign body sensation, was recorded in TORS patients. Conclusions: Both the coblation and TORS groups showed similar surgical outcomes, TORS achieved PSG results non‐inferior to and complication rates comparable to coblation. [ABSTRACT FROM AUTHOR]

A new all‐digital delay‐locked loop (ADDLL) using successive‐approximation register (SAR) control scheme is presented. The proposed circuit architecture can effectively perform the per‐bit acquisition within one clock cycle. Therefore, the divider for generating internal SAR clocks can be further removed to achieve fast‐locking capability. Meanwhile, the harmonic‐locking problem that often occurs in a wide range of operating frequencies is also eliminated. The test chip is designed and verified with CMOS 0.18 μm technology. The measured acquisition cycles for all operating frequencies (100–800 MHz) are constant as 11 when a 10‐bit digital‐controlled delay line is employed. The rms/peak‐to‐peak jitters at the highest and lowest frequencies are 0.775/5.73 and 1.08/8.27 ps, respectively. The chip core occupies an active area of 0.015 mm2 and consumes 9.4 mW at 800 MHz. [ABSTRACT FROM AUTHOR]

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]

The wire windings and magnetic performance of the mini-pole superconducting undulator (SCU) at the National Synchrotron Radiation Research Center (NSRRC) are being improved. NbTi superconducting (SC) wire with a rectangular cross section 0.51 mm x 0.77 mm was wound on a racetrack iron pole. The designed field strength was 1.4 T at excitation current 510 A. The bath LHe-cryostat cools the SC wire directly and uniformly using LHe. A stainless-steel (SS) beam duct (thickness 0.3 mm) is designed to separate the ultra-high vacuum (UHV) from the storage ring and the LHe. The SS beam duct is glued to the dummy arrays with resin epoxy. The dummy arrays provide a strong support for the beam duct, providing against deformity from a pressure differential. A vacuum test was performed with a short version of a beam duct (length 400 mm) at low temperature. This paper describes the construction of the magnet, the measurement of the field and the testing of the SS beam duct. [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]

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. [ABSTRACT FROM AUTHOR]

A cryogen-free cryostat for a superconducting undulator with a period of 15 mm (SU15) was developed at the National Synchrotron Radiation Research Center (NSRRC). A 0.44 mm-thin superconducting NbTi wire was wound on iron pole with a racetrack profile. The design field strength of SU15 was 1.4 T and the coil had 148 turns/pole at 230 A; the magnet gap was 5.6 mm. The liquid helium (LHe) recondensation cryostat was designed for SU15. The cryostat provides the advantage of uniform cooling and reduces the amount of LHe consumed. A 0.3 mm-thick stainless steel (SS) beam duct was formed to separate the vacuum in the storage ring from the magnet. Therefore, all of dirty material is produced out of storage ring vacuum. Most of the heat leaked from the LHe vessel leaks from the LHe-fill port heat leak and the 300 K-4.2 K beam duct or was associated with image current power dissipation (ICPD) and bending magnet power dispersion (BMPD). The leaking of heat from the main coil was prevented by the high-temperature superconducting current leads (HTSC). The beam duct was coated with a copper layer with a high-RRR ratio to reduce image current heating. The heat loads on the magnet were cooled using two 1.5 W Gifford-MacMahon (GM) type cryocoolers via LHe medium. [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]

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/mm², 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. [ABSTRACT FROM AUTHOR]

A superconducting wiggler with a magnetic period of 6.0 cm (SW6) and a peak field of 3.2 T has been designed and fabricated in the National Synchrotron Radiation Research Center (NSRRC). The beam duct separates the electron beam from the cryogenic system of the magnet. The heat load on the beam duct should be low to stabilize the operation of the superconducting magnets. However, outgassing caused by synchrotron radiation at an electron energy of 1.5 GeV and a current of 200 mA must be reduced. Accordingly, operating the system at a higher temperature can minimize the adsorption of molecules on the beam duct. Therefore, the beam duct system and its connection by finite element analysis are designed to optimize the operating temperature of the beam duct at between 100 and 120 K. Performance of the beam duct is established to comply with specifications during the operation of magnet. [ABSTRACT FROM AUTHOR]

Abstract: A 3.2T superconducting wiggler with a periodic length of 6cm and 32 poles was designed and fabricated as an X-ray source. The beam duct of this magnet is a semi-cold, ultra-high vacuum chamber that consists of an aluminum and stainless steel taper. The number of poles in this magnet design is even, to minimize the integral strengths of the multipole components. Two measurement systems—involving room-temperature and cryogenic Hall probes—were set up to measure the field of the superconducting wiggler. A cryogenic plant that supplied liquid helium and nitrogen to the superconducting wiggler has already been established. The performance of magnet construction is good and the commissioning of the superconducting wiggler in the storage ring has been successful. No trim coil compensation on the magnet is required to adjust the electron beam orbit. Furthermore, the electron beams exhibit no loss and remain highly stable after the superconducting wiggler has been quenched. [Copyright &y& Elsevier]

Mini-pole (short period) in-vacuo superconducting undulators, a vert5ical-winding racetrack coil structure, a horizontal-winding racetrack coil structure and a staggered array structure, were studied for use in the X-ray source in a 1.5 GeV or a medium-energy 3 GeV storage ring. The magnetic arrays are all installed in the ultra-high vacuum environment, required for passing electron beams. In a periodic length of 15 mm and a gap of 5 mm, field strengths of 1.5 T, 1.5 T and 0.7 T can be generated in the three different structures, respectively. Additionally, the staggered undulator with variable-period length or a translator structure with different periodic length can yield various deflection parameters k, by driving a longitudinal solenoid field of 0.8 T. Accordingly, this study addresses the magnet structure of and mechanism of the magnet, and the advantages and disadvantages of the structures of these undulators. The spectral characteristics and the magnetic field features of these undulators are also studied. [ABSTRACT FROM AUTHOR]

Deals with a study which describes 'static scan' and 'dynamic scan' methods to measure the integral magnetic field using a long-loop-flip coil and to characterize the elliptically polarizing undulator and other insertion device magnets in a synchrotron light source. Long-loop-flip coil measurement system; Measurement algorithm and theoretical analysis.

A device is described and mathematically analyzed which creates electrostatic multipole potentials at least up to rank 3 in a 2 cm diam spherical region. The fields in the Stark ball are produced by the application of programmed voltages to 24 conducting rods that are inserted symmetrically in an empty 5 cm conducting cavity. Three mutually orthogonal unobstructed paths through the center of the device between the rods are provided for access of light and particle beams, and four other tetrahedrally located openings can be added for beams, detectors, or imaging. The device is intended for application in atom or molecule trapping and cooling, recoil-ion momentum spectroscopy, particulate analysis, reactive scattering, and coherent control. Potential distributions can be established, altered, and rotated on subnanosecond time scales, and frequencies higher than 20 GHz can be introduced via the same electrodes. Uniform fields, i.e., first-rank multipoles, quadrupole, and octupole potentials can be programmed and superposed with arbitrary and independent time profiles, so that the device may be applied to the study of orientational properties of complex anisotropic molecules, pollens, grains of dust, and other particulates. The device is nonmagnetic. An extensive analysis of fields in the center region, fringing fields, and multipole purity up to rank 7 has been carried out, and recipes are given for pure (ℓ,m)=(1,0), (2,0), and (3,0) multipoles. The principles and methods laid out here and applied to a "truncated octahedron" can be applied to the design of electrostatic environments having fewer or more independent electrodes in any polyhedral geometry. [ABSTRACT FROM AUTHOR]

A 4-m-long elliptically polarizing undulator (EPU5.6) device with an Apple-II structure is installed in the Synchrotron Radiation Research Center storage ring. This is the longest EPU device with an Apple-II structure worldwide. The errors of the magnet construction and the assembly process are among the several factors that can degrade the spectral performance. This study describes the mechanical design concept and construction that reduce magnetic field errors to keep high performance of the magnet. The electron orbit distortion in various polarization radiation modes is discussed with reference to a global feedback system and a feed forward table with following gap and phase. The beam dynamic effects are also investigated when the phase and magnetic gap are changed. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Presents information on a study which described a Hall-probe automatic measurement system for magnetic field measurement of the C-type rectangular combined function bending magnet and insertion device magnets. Description of the automatic measurement system; System sequential architecture; Discussion.

Discusses the magnetic field features of the combined function bending magnet with dipole and quadrupole field components. Mapping trajectory and definition; Measurement and analysis of the results; Conclusion.

Examines the design parameters and performance of double-crystal monochromator (DCM) for an x-ray beamline. Factors affecting the stability of motions and overall size of the monochromator; Development of a software program to control the motion of DCM; Absorption spectrum of the device.

A special theoretical concept involving the harmonic magnetic-field measurement and analysis method using a fixed angle Hall probe was developed at the Synchrotron Radiation Research Center (SRRC) for measuring as well as analyzing the triple bending achromat magnets of the storage ring. The method can be used to simulate the harmonic magnetic-field calculation of the two-dimensional (2D) "MAGNET" program. This method has a quite simple mechanism. The Hall plate was fixed at a 0° angle with respect to the horizontal plane of magnet to measure only the vertical field. Additionally, the 2D nonlinear least-square fitting was used to fit the mapping data so as to find the normal and skew multipole field strength. If necessary, the angle of Hall probe could be rotated 90° precisely for measuring the horizontal field. Consequently, the skew dipole field could be obtained. A real-time Hall-probe automatic magnetic-field measurement system was also developed for fulfilling the concept of the harmonic field measurement. Some special mapping trajectories for different kinds of magnets were discussed to match this special theoretical concept with the analysis methodology. This was done so as to obtain the reliable and accurate harmonic field strength. The accuracy and precision of the harmonic field strength measurement and analysis of this method being better than ± 0.01% was confirmed by experimental results. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The pulsed wire method for magnetic field measurement has been developed by several groups. In most cases the thin wires were used and only the short magnets were measured to ignore the dispersion due to stiffness of the wires. In the application to the long insertion devices, a lot of spurious signals occurred and contaminated the normal field signals. In this article we demonstrate a new approach to applying the pulsed wire method to a long insertion undulator with a high field. Thick wire is used instead. Then we can cancel the dispersion and trace back the normal field signal by using the fast Fourier transform calculation. The results are quite comparable to Hall probe measurement. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR]

A new all-digital delay-locked loop (ADDLL) using successiveapproximation register (SAR) control scheme is presented. The proposed circuit architecture can effectively perform the per-bit acquisition within one clock cycle. Therefore, the divider for generating internal SAR clocks can be further removed to achieve fast-locking capability. Meanwhile, the harmonic-locking problem that often occurs in a wide range of operating frequencies is also eliminated. The test chip is designed and verified with CMOS 0.18 µm technology. The measured acquisition cycles for all operating frequencies (100-800 MHz) are constant as 11 when a 10-bit digital-controlled delay line is employed. The rms/peak-to-peak jitters at the highest and lowest frequencies are 0.775/5.73 and 1.08/8.27 ps, respectively. The chip core occupies an active area of 0.015 mm² and consumes 9.4 mW at 800 MHz. [ABSTRACT FROM AUTHOR]

This work demonstrates by in vacuo X-ray photoelectron spectroscopy and grazing-incidence X-ray diffraction that Ru(EtCp)2 and O* radical-enhanced atomic layer deposition, where EtCp means the ethylcyclopentadienyl group, provides the growth of either RuO2 or Ru thin films depending on the deposition temperature (Tdep), while different mechanisms are responsible for the growth of RuO2 and Ru. The thin films deposited at temperatures ranging from 200 to 260 °C consisted of polycrystalline rutile RuO2 phase revealing, according to atomic force microscopy and the four-point probe method, a low roughness (∼1.7 nm at 15 nm film thickness) and a resistivity of ≈83 µΩ cm. This low-temperature RuO2 growth was based on Ru(EtCp)2 adsorption, subsequent ligand removal, and Ru oxidation by active oxygen. The clear saturative behavior with regard to the precursor and reactant doses and each purge time, as well as the good step coverage of the film growth onto 3D structures, inherent to genuine surface-controlled atomic layer deposition, were confirmed for the lowest Tdep of 200 °C. However, at Tdep = 260 °C, a competition between film growth and etching was found, resulted in not-saturative growth. At higher deposition temperatures (300–340 °C), the growth of metallic Ru thin films with a resistivity down to ≈12 µΩ cm was demonstrated, where the film growth was proved to follow a combustion mechanism known for molecular oxygen-based Ru growth processes. However, this process lacked the truly saturative growth with regard to the precursor and reactant doses due to the etching predominance. [ABSTRACT FROM AUTHOR]

One major pathological hallmark of Alzheimer's disease (AD) is accumulation of senile plaques in patients' brains, mainly composed of amyloid beta-peptide (Aβ). Nicotinamide adenine dinucleotide (NAD) has emerged as a common mediator regulating energy metabolism, mitochondrial function, aging, and cell death, all of which are critically involved in neuronal demise observed in AD. In this work, we tested the hypothesis that NAD may attenuate Aβ-induced DNA damages, thereby conferring neuronal resistance to primary rat cortical cultures. We found that co-incubation of NAD dose-dependently attenuated neurotoxicity mediated by Aβ25-35 and Aβ1-42 in cultured rat cortical neurons, with the optimal protective dosage at 50 mM. NAD also abolished the formation of reactive oxygen species (ROS) induced by Aβ25-35. Furthermore, Aβs were capable of inducing oxidative DNA damages by increasing the extents of 8-hydroxy-2´-deoxyguanosine (8-OH-dG), numbers of apurinic/apyrimidinic (AP) sites, genomic DNA single-stranded breaks (SSBs), as well as DNA double-stranded breaks (DSBs)/fragmentation, which can all be attenuated upon co-incubation with NAD. Our results thus reveal a novel finding that NAD is protective against DNA damage induced by existing Aβ, leading ultimately to neuroprotection in primary cortical culture. [ABSTRACT FROM AUTHOR]

The optical design and performance of the recently opened 13A biological small‐angle X‐ray scattering (SAXS) beamline at the 3.0 GeV Taiwan Photon Source of the National Synchrotron Radiation Research Center are reported. The beamline is designed for studies of biological structures and kinetics in a wide range of length and time scales, from angstrom to micrometre and from microsecond to minutes. A 4 m IU24 undulator of the beamline provides high‐flux X‐rays in the energy range 4.0–23.0 keV. MoB4C double‐multilayer and Si(111) double‐crystal monochromators (DMM/DCM) are combined on the same rotating platform for a smooth rotation transition from a high‐flux beam of ∼4 × 1014 photons s−1 to a high‐energy‐resolution beam of ΔE/E ≃ 1.5 × 10−4; both modes share a constant beam exit. With a set of Kirkpatrick–Baez (KB) mirrors, the X‐ray beam is focused to the farthest SAXS detector position, 52 m from the source. A downstream four‐bounce crystal collimator, comprising two sets of Si(311) double crystals arranged in a dispersive configuration, optionally collimate the DCM (vertically diffracted) beam in the horizontal direction for ultra‐SAXS with a minimum scattering vector q down to 0.0004 Å−1, which allows resolving ordered d‐spacing up to 1 µm. A microbeam, of 10–50 µm beam size, is tailored by a combined set of high‐heat‐load slits followed by micrometre‐precision slits situated at the front‐end 15.5 m position. The second set of KB mirrors then focus the beam to the 40 m sample position, with a demagnification ratio of ∼1.5. A detecting system comprising two in‐vacuum X‐ray pixel detectors is installed to perform synchronized small‐ and wide‐angle X‐ray scattering data collections. The observed beamline performance proves the feasibility of having compound features of high flux, microbeam and ultra‐SAXS in one beamline. [ABSTRACT FROM AUTHOR]

An S-band thermionic 1.5-cell rf gun injector system is being built at NSRRC for Taiwan Photon Source (TPS) booster. At optimized field ratio, an electron beam with linear energy chirp can be generated by the rf gun. The beam is then compressed by an alpha magnet such that ultra-short electron bunches at femto-second bunch length can be obtained. Particle dynamics has been studied for an rf gun with nose cone at the cathode, simulation results show that 74 pC bunches at about 97 fs is achievable. Some of the critical components such as the rf gun and alpha magnet have been fabricated and being tested in house. Experiments for intense coherent THz radiations and tunable femto-second X-ray from ultra-short bunches are being proposed as future applications. [ABSTRACT FROM AUTHOR]

Chronic myelomonocytic leukaemia (CMML) is a preleukaemic condition with myeloproliferative features, and classified as a part of myelodysplastic syndrome (MDS). Other than alkylating agents and topoisomerase II inhibitors, there is less evidence that chemotherapeutic drugs are associated with therapy-related CMML, acute leukaemia or MDS. We present a patient who developed CMML within 2 years of platinum-based chemotherapy for a metastatic non-small cell lung cancer. He received a cumulative dose of 240 mg/m2 of cisplatin, and 1123 mg/m2 of carboplatin before developing CMML. The cytogenetic study revealed trisomy 8. This is the first reported case that links platinum-based therapy with development of CMML with trisomy 8. Although the relationship between platinum therapy and the development of CMML is difficult to assess due to combinational nature of therapy in most cases, physicians should consider the possibility of CMML in patients with symptoms or signs suggestive of haematologic malignancy after platinum therapy. [ABSTRACT FROM AUTHOR]

The resistive switching mechanism of 20- to 57-nm-thick TiO2 thin films grown by atomic-layer deposition was studied by current-voltage measurements and conductive atomic force microscopy. Electric pulse-induced resistance switching was repetitively (> a few hundred times) observed with a resistance ratio >102. Both the low- and high-resistance states showed linear log current versus log voltage graphs with a slope of 1 in the low-voltage region where switching did not occur. The thermal stability of both conduction states was also studied. Atomic force microscopy studies under atmosphere and high-vacuum conditions showed that resistance switching is closely related to the formation and elimination of conducting spots. The conducting spots of the low-resistance state have a few tens times higher conductivity than those of the high-resistance state and their density is also a few tens times higher which results in a ∼103 times larger overall conductivity. An interesting finding was that the area where the conducting spots do not exist shows a few times different resistance between the low- and high-resistance state films. It is believed that this resistance change is due to the difference in point defect density that was generated by the applied bias field. The point defects possibly align to form tiny conducting filaments in the high-resistance state and these tiny conducting filaments gather together to form stronger and more conducting filaments during the transition to the low-resistance state. [ABSTRACT FROM AUTHOR]

A strong field and short period undulator can be a desirable light source device in a storage ring or a free-electron laser. Bulk YBCO can be used to construct a high-temperaturesuperconducting undulator in a staggered array structure. The YBCO material in form of 32 mm diameter and 2.5 mm thick was used to assemble a staggered magnet array. The period length is 5 mm and the magnet gap is 4 mm. To estimate the strength of a sinusoidal field and to optimize the end-pole design to minimize the first (i.e., electron angle) and second field integral (electron position), an energy-minimization method (EM-method) based on Bean's model to simulate the field trapped in the HTS-Block is introduced. In this paper, we focus on promoting the practical value of the EM-method simulation. Combining the experimental experience of a YBCO staggered undulator and the simulation experience based on the EM-method, we address some issues to enhance the efficacy of this undulator design. [ABSTRACT FROM AUTHOR]

The structural and ferroelectric properties of lightly La-doped (1 mol. %) HfO2 thin films grown by plasma-assisted atomic layer deposition were examined. An annealing temperature as low as 400°C crystallized the film into the desired orthorhombic phase, which resulted in it displaying promising ferroelectric performance. The remanent polarization (Pr) increased with annealing temperature, but the performance enhancement seemed to saturate at 500°C. A slight decrease in the dielectric constant, which was associated with the preferential formation of a polar orthorhombic phase at higher temperatures, was also observed. The long-term wake-up effect, i.e., a marked rise in the 2Pr value during field cycling, was demonstrated for films processed at all annealing temperatures. The presence of domain groups with opposite internal electric biases was found in the pristine state, while the internal bias distribution became more uniform during wake-up. The endurance of up to 4 x 108 switching cycles without marked fatigue using bipolar pulses with a duration of 600 ns, and an amplitude of ±3MV/cm was demonstrated. [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]

The article offers information regarding the treatment of Meniere-s disease. It mentions the use of gentamicin instead of streptomycin in chemical labyrinthectomy for intractable Ménière's disease. It states that intratympanic streptomycin powder eliminates the need for multiple applications, reduces the possibility of drug leakage through the eustachian tube and allows for effective direct diffusion into the perilymph.

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]

For the study of high-temperature superconductors and for the application of superconductivity, a superconducting high-field magnetization system with a hybrid superconducting coil was designed. This coil is composed of superconducting wires of three kinds—HTS YBCO 2G-wire, high-field and low-field NbTi wires. Three principal purposes of building this system are to inspect the characteristics of disk-shape bulk YBCO, to develop a HTS-bulk undulator, and to magnetize a portable HTS-bulk high-field magnet for application to a resonant X-ray scattering experiment. With four steps of temperature decrease, a two-stage GM-type cryocooler and liquid nitrogen provide cooling for the magnetization system. The hybrid superconducting coil, two cryogenic systems for the magnetization system and the portable HTS-bulk magnet, and the control and monitor systems that were designed are discussed. [ABSTRACT FROM PUBLISHER]

In material research, the characteristics of novel materials vary greatly with the environment. A magnet with a strong field will be developed for an experimental station for resonant X-ray scattering to investigate the magnetic properties of materials. This magnet will be developed with high-temperature superconductor (HTS) bulk YBa2Cu3O7 and magnetized with a HTS coil magnet wound with 2G HTS wire. HTS (RE) BCO will be selected to construct the coil of this magnet. Both the bulk and coil magnets will be assembled on the same movable system. The bulk HTS magnet will provide flux density greater than 4 T with a gap 34 mm that can accommodate the sample holder of the experimental station. The bulk magnet will be cooled with cryocoolers to 29 K and the coil magnet to 4.2 K; the coil magnet is separable from the bulk magnet after the field is trapped. We describe the concept of the magnetic-field calculation, the overall design of these magnets, and the cooling algorithm for the bulk HTS magnet system. [ABSTRACT FROM AUTHOR]

Abstract: To mitigate hyperacute rejection, pigs have been generated with α-Gal transferase gene knockout and transgenic expression of human decay accelerating factor (hDAF), MCP, and CD59. Additionally, heme-oxygenase-1 (HO-1) has been suggested to defend endothelial cells. Sera (MS) (0%, 1%, 5%, 10%, and 15%) from Formosan macaques (Macaca cyclopis, MC), an Old World monkey wildly populated in Taiwan, was used to test the protective in vitro, effects of hDAF or hDAF/hHO-1 on porcine aortic endothelial cells (pAEC) derived from hDAF+, hDAF+/hHO-1+, and hDAF+/hHO-1− and 1 nontransgenic pAEC. Ten percent human serum (HS) served as a positive control. When MS addition increased to 10% or 15%, all transgenic pAEC exhibited a greater survival than nontransgenic pAEC. Noticeably, 15% MS reduced survived to <10% versus >40% in nontransgenic and transgenic pAEC, respectively. These results revealed that hDAF exerted protective effects against MC complement activation. However, comparing with 10% MS and HS in pAEC of nontransgenic pigs, the survivability was higher in HS, suggesting that complement activation by MS was more toxic than that by HS. Furthermore, hDAF+/hHO-1+ showed no further protection against effects of MS on transgenic pAEC. [ABSTRACT FROM AUTHOR]