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Chen, J.-R.

Paper Title Page
MPPT032 Construction and Performance of Superconducting Magnets for Synchrotron Radiation 2218
 
  • C.-S. Hwang, C.-H. Chang, C.-K. Chang, H.-P. Chang, C.-T. Chen, H.-H. Chen, J. Chen, J.-R. Chen, Y.-C. Chien, T.-C. Fan, G.-Y. Hsiung, K.-T. Hsu, S-N. Hsu, M.-H. Huang, C.-C. Kuo, F.-Y. Lin
    NSRRC, Hsinchu
  
  Two superconducting magnets, one wavelength shifter (SWLS) with a field of 5 T and one wiggler (SW6) with a field of 3.2 T, were constructed and routinely operated at NSRRC for generating synchrotron x-rays. In addition, three multipole wigglers (IASW) with fields of 3.1 T will be constructed and installed each in the three achromatic short straight sections. A warm beam duct of 20 mm inner gap and a 1.5 W GM type cryo-cooler were chosen for the SWLS to achieve cryogen-free operation. For the SW6, a cold beam duct of 11 mm inner gap was kept at 100 K temperature and no trim coil compensation is necessary for its operation. Meanwhile, no beam loss was observed when the SW6 was quenched. A cryogenic plant with cooling power of 450 W was constructed to supply the liquid helium for the four superconducting wigglers. The design concept, magnetic field quality, the commissioning results, and the operation performance of these magnets will be presented.  
RPAE049 Revision of Booster to Storage Ring Transport Line Design and Injection Scheme for Top-Up Operation at NSRRC 3085
 
  • M.-H. Wang, H.-P. Chang, J. Chen, J.-R. Chen, K.-T. Hsu, C.-C. Kuo, G.-H. Luo
    NSRRC, Hsinchu
  
  In order to help the operation of constant current, the optics of booster to storage ring transport line (BTS) design is reinvestigated. The initial twiss parameters are derived by measurement. The optics of the transport line is readjusted according to the measured initial beam parameters. The design of pulse width of the injection kicker is also changed from 1.2μsecond to 2.0μsecond. The injection scheme is reviewed and the effects of the kicker error on both injected beam and stored beam are investigated and shown in this report.  
RPAT059 The SRI Beam Size Monitor Developed at NSRRC 3465
 
  • T.C. Tseng, J.-R. Chen, H.C. Ho, C.-K. Kuan, C.J. Lin, S.Y. Perng, D.-J. Wang, J. Wang
    NSRRC, Hsinchu
  
  A beam size monitor based on the synchrotron radiation interferometer (SRI) was installed in the NSRRC TLS. This monitor consists of a simple diagnostic beamline with a water-cooled beryllium mirror inside and a detecting optical system for both vertical and horizontal beam size measurement. The beam sizes measured are 48 micron and 160 micron respectively and are more close to the theoretical values than the synchrotron image monitor. Comparing with other monitors, at least 1 micron beam size variation is detectable. To minimize the thermal effect, the mirror is located far away from the source point and closed to the detecting optical system. The thermal distortion of the mirror is quite small measured by a portable long trace profiler (LTP) and agrees with the simulating analysis. The detailed monitor system design and testing results are presented in this paper.  
RPPE072 The Improvement and Data Acquisition Systems on Electrical Systems and Grounding Networks in NSRRC 3868
 
  • Y.-H. Liu, J.-C. Chang, J.-R. Chen, Y. Lin, Z.-D. Tsai
    NSRRC, Hsinchu
  
  Funding: NSRRC.

The purpose of this paper is to declare the improvement on electrical and grounding systems in NSRRC. In electrical power system, an Automated Voltage Regulator (AVR) was established to RF system in 2003. The variation of voltage supply from Taiwan Power Company (TPC) is reduced from 3% to 0.2% through the AVR system. And a Supervisory Control and Data Acquisition (SCADA) system was also setup to monitoring the electrical power conditions in each power station. After the high precision grounding systems were constructed in 2004, the stability of beam line was raised. For comprehending the grounding current and noise control, a grounding monitoring system with 32 channels was built in the storage ring. The grounding currents of 4 kickers, one septum and grounding bus are on-line acquisition. Two Electromagnetic Field (EMF) apparatuses were also installed to collect electrical and magnetic fields in the R1 section. It was observed that the electromagnetic field was correlated to grounding currents in certain locations. Injection effects were clearly found in most monitored data. Some improvement works, including expansion of the grounding monitoring system composing analytical software will integrate in the next step.

 
RPPE006 Air Temperature Analysis and Control Improvement for the Storage Ring Tunnel 1027
 
  • J.-C. Chang, Z.-D. Tsai
    NSRRC, Hsinchu
  • J.-R. Chen
    NTHU, Hsinchu
  • M. Ke
    NTUT, Taipei
  
  The stability of the electron beam orbit had been observed to be sensitive to the utility conditions. The stability of air temperature in the storage ring tunnel is one of the most critical factors. Accordingly, a series of air conditioning system upgrade studies and projects have been conducted at the Taiwan Light Source (TLS). Computational fluid dynamics (CFD) is applied to simulate the flow field and the spatial temperature distribution in the storage ring tunnel. The circumference and the height of the storage tunnel are 120m and 2.8m, respectively. The temperature data and the flow rates at different locations around the storage ring tunnel are collected as the boundary conditions. The k-epsilon turbulence model is applied to simulate the flow field in the three dimensional space. The global air temperature variation related to time in the storage ring tunnel is currently controlled within ±0.1 degree C. However, the temperature difference between two different locations is as high as 2 degree C. Some measures improving the temperature uniformity will be taken according to the CFD simulation results.  
RPPE007 High Precision Temperature Control and Analysis of RF Deionized Cooling Water System 1057
 
  • Z.-D. Tsai, J.-C. Chang, C.-Y. Liu
    NSRRC, Hsinchu
  • J.-R. Chen
    NTHU, Hsinchu
  
  Previously, the Taiwan Light Source (TLS) has proven the good beam quality mainly depends on the utility system stability. A serial of efforts were devoted to these studies. Further, a high precision temperature control of the RF deionized cooling water system will be achieved to meet the more critical stability requirement. The paper investigates the mixing mechanism through thermal and flow analysis and verifies the practical influences. A flow mixing mechanism and control philosophy is studied and processed to optimize temperature variation which has been reduced from ±0.1? to ±0.01?. Also, the improvement of correlation between RF performance and water cooling stability will be presented.