Author: Li, D.B.
Paper Title Page
MOPAB380 Status and Progress of the RF System for High Energy Photon Source 1165
 
  • P. Zhang, J. Dai, Z.W. Deng, L. Guo, T.M. Huang, D.B. Li, J. Li, Z.Q. Li, H.Y. Lin, Y.L. Luo, Q. Ma, F. Meng, Z.H. Mi, Q.Y. Wang, X.Y. Zhang, F.C. Zhao, H.J. Zheng
    IHEP, Beijing, People’s Republic of China
  
  Funding: This work was supported in part by High Energy Photon Source, a major national science and technology infrastructure in China and in part by the Chinese Academy of Sciences.
High En­ergy Pho­ton Source (HEPS) is a 6 GeV dif­frac­tion-lim­ited syn­chro­tron light source cur­rently under con­struc­tion in Bei­jing. It adopts a dou­ble-fre­quency RF sys­tem with 166.6 MHz as fun­da­men­tal and 499.8 MHz as third har­monic. The fun­da­men­tal cav­ity is mak­ing use of a su­per­con­duct­ing quar­ter-wave β=1 struc­ture and the third har­monic is of su­per­con­duct­ing el­lip­ti­cal sin­gle-cell geom­e­try for the stor­age ring, while nor­mal-con­duct­ing 5-cell cav­i­ties are cho­sen for the booster ring. A total of 900 kW RF power shall be de­liv­ered to the beam by the 166.6 MHz cav­i­ties and the third har­monic cav­i­ties are ac­tive. All cav­i­ties are dri­ven by solid-state power am­pli­fiers and the RF fields are reg­u­lated by dig­i­tal low-level RF con­trol sys­tems. The cav­ity and an­cil­lar­ies, high-power RF sys­tem and low-level RF con­trol sys­tem are in the pro­to­typ­ing phase. This paper pre­sents the cur­rent sta­tus and progress of the RF sys­tem for HEPS. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB380  
About • paper received ※ 09 May 2021       paper accepted ※ 09 June 2021       issue date ※ 24 August 2021  
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MOPAB390 Development of a 166.6 MHz Low-Level RF System by Direct Sampling for High Energy Photon Source 1189
 
  • D.B. Li, H.Y. Lin, Q.Y. Wang, P. Zhang
    IHEP, Beijing, People’s Republic of China
  
  Funding: This work was supported by High Energy Photon Source, a major national science and technology infrastructure in China.
A dig­i­tal low-level radio fre­quency (LLRF) sys­tem by di­rect sam­pling has been pro­posed for 166.6 MHz su­per­con­duct­ing cav­i­ties at High En­ergy Pho­ton Source (HEPS). The RF field in­side the cav­i­ties has to be con­trolled bet­ter than ±0.1% (peak to peak) in am­pli­tude and ±0.1 deg (peak to peak) in phase. Con­sid­er­ing that the RF fre­quency is 166.6 MHz, which is well within the ana­log band­width of mod­ern high-speed ADCs and DACs, di­rect RF sam­pling and di­rect dig­i­tal mod­u­la­tion can be achieved. A dig­i­tal LLRF sys­tem uti­liz­ing di­rect sam­pling has there­fore been de­vel­oped with em­bed­ded ex­per­i­men­tal physics and in­dus­trial con­trol sys­tem (EPICS) in the field pro­gram­ma­ble gate array (FPGA). The per­for­mance in the lab has been char­ac­ter­ized in a self-closed loop with a resid­ual peak-to-peak noise of ±0.05% in am­pli­tude and ±0.03 deg in phase, which is well below the HEPS spec­i­fi­ca­tions. Fur­ther tests on a warm 166.6 MHz cav­ity in the lab are also pre­sented. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB390  
About • paper received ※ 17 May 2021       paper accepted ※ 09 June 2021       issue date ※ 30 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)