Author: Huang, J.Y.
Paper Title Page
TUOBB02 Commissioning of the PLS-II 1089
 
  • S. Shin, J.Y. Choi, T. Ha, J.Y. Huang, I. Hwang, W.H. Hwang, Y.D. Joo, C. Kim, D.T. Kim, D.E. Kim, J.M. Kim, M. Kim, S.H. Kim, S.-C. Kim, S.J. Kwon, B.-J. Lee, E.H. Lee, H.-S. Lee, H.M. Lee, J.W. Lee, S.H. Nam, E.S. Park, I.S. Park, S.S. Park, S.J. Park, Y.G. Son, J.C. Yoon
    PAL, Pohang, Kyungbuk, Republic of Korea
  • J-Y. Kim, B.H. Oh
    KAERI, Daejon, Republic of Korea
  • J. Lee
    POSTECH, Pohang, Kyungbuk, Republic of Korea
  
  The Pohang Light Source (PLS) has operated for 14 years successfully. To meet the request of the increasing user community, the PLS-II that is the upgrade project of PLS has been completed. Main goals of the PLS-II are to increase beam energy to 3 GeV, to increase number of insertion devices by the factor of two (20 IDs), to increase beam current to 400 mA and to reduce beam emittance below 10 nm with existing PLS tunnel and injection system. The PLS-II had been commissioned over the six months. During commissioning, we achieved 14 insertion devices operation and top-up operation with 100 mA beam current and 5.8 nm beam emittance. In this presentation, we report the experimental results from the PLS-II commissioning.  
slides icon Slides TUOBB02 [3.484 MB]  
 
WEPPC023 Status and Progress of RF System for the PLS-II Storage Ring 2254
 
  • M.-H. Chun, J.Y. Huang, Y.D. Joo, H.-S. Kang, H.-G. Kim, C.D. Park, H.J. Park, I.S. Park, Y.U. Sohn, I.H. Yu
    PAL, Pohang, Kyungbuk, Republic of Korea
  
  Funding: Supported by the Korea Ministry of Science and Technology
The RF system for the Pohang Light Source (PLS) storage ring was upgraded for PLS-II project of 3.0GeV/400mA from 2.5GeV/200mA. the RF system is commissioning with five normal conducting(NC) RF cavities at total maximum RF power of 280kW to the cavities with two 300kW klystron and two 75kW klystron amplifiers in 2011. The super conducting(SC) cavities will be installed on August 2012 because of long delivery. Therefore three NC RF cavities will be replaced with two SC cavities with cryomodules, and operated with cryogenics, digital low level, and 300kW klystron high power system. Also we are preparing the third SC cavity stand to increase the storage ring current up to 400mA with all insertion devices operation. This paper describes the present installation, commissioning, operation status, upgrade progress, and future plan of the RF system for the upgraded project of PLS-II storage ring. 		 
 
WEPPC024 Preliminary Test of Superconducting RF Cavities for PLS-II 2257
 
  • Y.U. Sohn, M.-H. Chun, J.Y. Huang, Y.D. Joo, H.-S. Kang, H.-G. Kim, S.H. Nam, C.D. Park, H.J. Park, I.S. Park, I.H. Yu
    PAL, Pohang, Kyungbuk, Republic of Korea
  
  Funding: This project is supported by the Korea Ministry of Science and Technology.
The main part of the Installation for the PLS-II upgrade was finished in June and is on the way to user operation through elaborate commissioning. Up to now, the achievement is 150 mA beam current at 3 GeV with multi-bunch mode with 5 normal conducting cavities which served in the PLS before. After installation of 2 SRF cavities in the summer of 2012, the PLS-II will have 300 mA beam current with 20 IDs by 2 superconducting RF cavities until July, 2014. Finally, one more superconducting cavity will be added in August, 2014, and beam current will rise to 400 mA. The two SRF cavities are under test and conditioning. The two main subsystems, SRF cavities and ceramic windows were tested independently to confirm their performance. Each cavity recorded its accelerating voltage as 3.27 MV and 3.24 MV at 4.2K, respectively. Two RF windows also passed their specification, 300 kW CW traveling wave and 150 kW CW standing wave. The preliminary tests of SRF cryomodules are reported in the presentation. 		 
 
WEPPD069 PLS-II Linac Upgrade 2681
 
  • B.-J. Lee, J.Y. Choi, S. Chunjarean, T. Ha, J.Y. Huang, I. Hwang, Y.D. Joo, C. Kim, M. Kim, S.H. Kim, S.J. Kwon, S.H. Nam, S.S. Park, S.J. Park, S. Shin, Y.G. Son
    PAL, Pohang, Kyungbuk, Republic of Korea
  
  This paper reports on the recent status of the Pohang Light Source (PLS)-II linac at Pohang Accelerator Laboratory (PAL). From 2009, the linac upgrade has been started increasing its energy from 2.5 GeV to 3 GeV aiming stable top-up mode operation. First, we show that the stability status of the two different types of modulators to meet the top-up condition which requires very stable modulator system in linac. Next, we introduce upgrade status those differ from their PLS (2.5 GeV) such as installation of the dual vacuum systems for the electron gun to replace it immediately, adding important diagnostic tools, and reutilization of the beam analysis system just after pre-injector. Finally we present the electron beam parameters measured by those diagnostic system.  
 
THPPC016 PLSII Linac RF Conditioning Status 3311
 
  • H.-S. Lee, J.Y. Huang, W.H. Hwang, H.-G. Kim, K.R. Kim, S.H. Kim, S.H. Kim, S.H. Nam, W. Namkung, S.S. Park, S.J. Park, Y.J. Park, S. Shin
    PAL, Pohang, Kyungbuk, Republic of Korea
  
  PLS linac has been upgraded in energy from 2.5 to 3.0 GeV. A klystron supplies RF power of 80 MW four acceleration structures through a SLED. But our machine is not enough RF power to get 3 GeV beam energy. So we have changed the RF scheme in four modules as a klystron supplies RF power of 80 MW two accelerating structures through a SLED. There were several problems during the RF conditioning and beam operation. So we will describe the conditioning results and the current status in this paper.  
 
THPPC057 S-band High Power RF System for 10 GeV PAL-XFEL 3419
 
  • W.H. Hwang, J.Y. Huang, Y.D. Joo, H.-S. Kang, H.-G. Kim, S.H. Kim, H.-S. Lee, Y.J. Park
    PAL, Pohang, Kyungbuk, Republic of Korea
  
  In PAL, We are constructing a 10GeV PxFEL project. The output power of the klystron is 80 MW at the pulse width of 4 ㎲ and the repetition rate of 120 Hz. In high power operation, it is important to decrease the rf electric field to protect rf break-down in high power rf components. To obtain the maximum beam, we must reduce the phase difference between waveguide branches including accelerating structure and minimize the environment influences. This paper describes the waveguide system and high power rf components for the PxFEL.  
 
THPPC058 S-band Low-level RF System for 10 GeV PAL-XFEL 3422
 
  • W.H. Hwang, J.Y. Huang, H.-S. Kang, H.-S. Lee, W.W. Lee
    PAL, Pohang, Kyungbuk, Republic of Korea
  
  In PAL, We are constructing a 10GeV PxFEL project. The output power of the klystron is 80 MW at the pulse width of 4 ㎲ and the repetition rate of 120 Hz. And the specifications of the rf phase and amplitude stability are 0.05 degrees(rms) and 0.01%(rms) respectively. We achieved the stability of 0.03 degrees(p-p) at low power rf output using a phase amplitude detection system(PAD) and phase amplitude control(PAC) system. This paper describes the microwave system and the PAD and PAC system for the PxFEL.  
 
THPPD054 Low Current Bipolar Magnet Power Supply System at the PLS-II Storage Ring 3635
 
  • S.-C. Kim, J.Y. Huang, K.R. Kim, S.H. Nam, S. Shin, Y.G. Son, C.W. Sung
    PAL, Pohang, Kyungbuk, Republic of Korea
  
  Funding: * This work is supported by the Ministry of Education, Science and Technology, Korea.
Lattice of the Storage Ring (SR) is changed from TDB to DBA, and beam energy is enhanced from 2.5 GeV to 3.0 GeV at the Pohang Light Source upgrade (PLS-II). At the PLS-II, Magnet Power Supplies (MPS) were newly designed according to magnet specification of the PLS-II. All MPSs are adopted switching type power conversion technology. Low current bipolar MPSs for vertical corrector(VC), horizontal corrector(HC), fast corrector(FC), aux.-quadrupole(AQ), skew(SK) and dipole trim coil(TR) magnets are H-bridge type. All MPSs are performed less than ± 10 ppm output current stability and adopted full digital controller. Except vertical corrector MPSs, all unipolar and bipolar MPSs are developed as embedded EPICS IOC. In this paper, we report on the development and characteristics of the bipolar MPS for the PLS-II Storage Ring. 		 
 
THPPD055 High Current Unipolar Magnet Power Supply System at the PLS-II Storage Ring 3638
 
  • S.-C. Kim, J.Y. Huang, K.R. Kim, S.H. Nam, S. Shin, Y.G. Son, C.W. Sung
    PAL, Pohang, Kyungbuk, Republic of Korea
  
  Funding: This work is supported by the Ministry of Education, Science and Technology, Korea.
Lattice of the Storage Ring (SR) is changed from TDB to DBA, and beam energy is enhanced from 2.5 GeV to 3.0 GeV at the Pohang Light Source upgrade (PLS-II). At the PLS-II, Magnet Power Supplies (MPS) were newly designed according to magnet specification of the PLS-II. All MPSs are adopted switching type power conversion technology. High current unipolar MPSs for bending(BD), main-quadrupole(MQ), sextupole(ST) and septum(SP) magnet are parallel operation type of unit stack buck type power supply. Unit stack of unipolar MPS has capability maximum 250A and operation 10kHz. BD and MQ MPS are adopted four stack as each stack 90degree phase shift switching, and have capability maximum 1000 A. ST MPS is adopted two stack as each stack 180degree phase shift switching, and have capability maximum 500 A. SP MPS is adopted single, and have capability maximum 250 A. All unipolar MPSs are developed as full digital controller, embedded EPICS IOC and operated less than ± 10ppm current stability. In this paper, we report on the development and characteristics of the high current unipolar MPS for the PLS-II SR. 		 
 
THPPD073 Development and Management of the Modulator System for PLS-II 3.0 GeV Electron Linac 3683
 
  • S.H. Kim, J.Y. Huang, S.J. Kwon, B.-J. Lee, Y.J. Moon, S.H. Nam, S.S. Park, S. Shin
    PAL, Pohang, Kyungbuk, Republic of Korea
  
  Funding: This work is supported by MEST(Ministry of Education, Science and Technology) and POSCO(Pohang Steel and Iron Company).
The Pohang Accelerator Laboratory (PAL) had started the upgrade project (called PLS-II) of the Pohang Light Source (PLS) from 2009 for increasing its energy from 2.5 GeV to 3 GeV and changing the operation mode from fill-up to top-up mode. Top-up mode operation requires high energy stability of the linac beam and machine reliability in the linac modulator systems. For providing the additional 0.5 GeV energy from the 2.5 GeV PLS linac, we added four units of the modulator system. We have two different types of the pulse modulator system for using existing pulse modulators, thyristor control type, in the upgrade project (PLS-II). The two types are thyristor control type and inverter power type. In the thyristor control type, a de-Qing system controls the modulator pulse forming network (PFN) charging voltage stability, and in the inverter power supply type, CCPS provides highly stable charging voltage to the modulator. We will present development and management of the pulse modulator system for obtaining machine reliability and stability from 3.0 GeV linac.