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This paper deals with the design of an analogue-to-digital converter (ADC) scheme for a highly precise magnet current supply (MPS). The MPSs are requires with stable and precise current specification in range of the ppm. To meet the requirements, the AD circuit is composed of parallel ADCs of low-medium resolution. Digitally, the oversampling and averaging are performed to increase both the effective resolution and the signal to noise ratio (SNR). The implemented AD circuit was improved about 18 dB (32 times oversampling). The MPS applied by the proposed ADC scheme provides more precise control and the stable current within 10 ppm at 200 A. The experiment used a dipole magnet of the PAL-XFEL and its results proved feasibility through precisely measurable DVM3458A (Keysight Co.)., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

All components of PAL-XFEL (Pohang Accelerator Laboratory's X-ray free-electron laser) were completely installed in December 2015, and Hard X-ray 0.1nm lasing achieved through its beam commissioning test and machine study on March 16, 2017. The beam line users has been performing various tests including pump-probe X-ray scattering, time-resolved x-ray liquidography, etc in the hard x-ray beam line since March 22. The energy and flux of x-ray photon beam generated from XFEL and synchronization timing should be stable to ensure successful time-resolved tests. Several parts that comprise the large scientific equipment should be installed and operated at precise three-dimensional location coordinates X, Y, and Z through survey and alignment to ensure their optimal performance. As time goes by, however, the ground goes through uplift and subsidence, which consequently changes the coordinates of installed components and leads to alignment errors ΔX, ΔY, and ΔZ. As a result, the system parameters change, and the performance of the large scientific equipment deteriorates accordingly. Measuring the change in locations of systems comprising the large scientific equipment in real time would make it possible to predict alignment errors, locate any region with greater changes, realign components in the region fast, and shorten the time of survey and alignment. For this purpose, a HLS's (hydrostatic leveling sensor) with 0.2um of resolution are installed and operated in a waterpipe of total length 1km in the PAL-XFEL building. This paper is designed to introduce the operating principle of the HLS, the installation and operation of the HLS system, and how to utilize the HLS system in order to ensure beam stabilization., Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada

Several parts that comprise the large scientific equipment should be installed and operated at precise three-dimensional location coordinates X, Y, and Z through survey and alignment to ensure their optimal performance. As time goes by, however, the ground goes through uplift and subsidence, which consequently changes the coordinates of installed components and leads to alignment errors. As a result, the system parameters change, and the performance of the large scientific equipment deteriorates accordingly. Measuring the change in locations of systems comprising the large scientific equipment in real time would make it possible to predict alignment errors, locate any region with greater changes, realign components in the region fast, and shorten the time of survey and alignment. For this purpose, a WPS's (wire position sensor) are installed in undulator section and a HLS's (hydrostatic leveling sensor) are installed in PAL-XFEL building. This paper is designed to introduce performance enhancements to reduce observed phenomena and measurement errors in the HLS system operation process., Proceedings of the Mechanical Eng.~Design of Synchrotron Radiation Equipment and Instrumentation, MEDSI2018, Paris, France

A high stable magnet power supply (MPS) was developed, which was a bipolar type with 200A of the output current at the 40V of output voltage. The MPS has been implemented by the digital signal processing technology using the DSP, FPGA, ADCs and so on. The output current stability of the MPS showed about 6ppm peak-to-peak in a short term experiment at 200A of its full output current. The long term stability was shown in 15 ppm peak-to-peak for 10 hours at 200A. And the others experimental results about the MPS were shown in this paper., Proceedings of the 29\textsuperscript{th} Linear Accelerator Conf., LINAC2018, Beijing, China

PLS-II operates for user service with the 34 beamlines since 2012. For engineering applications, especially for thick metal samples, a high energy X-ray beamline is under consideration to cover a photon energy up to §I{100}{keV} or beyond. By comparing the radiation spectra from various insertion devices types, superconducting wiggler was found to be a most promising candidate. A feasibility study to install the high field wiggler in the PLS-II ring is presented in this paper. Electron beam dynamics studies for a minimum impact on the electron beam parameters and engineering consideration to add more magnets are carried out., Proceedings of the 60th ICFA Advanced Beam Dynamics Workshop on Future Light Sources, FLS2018, Shanghai, China