Keyword: cavity
Paper Title Other Keywords Page
MOPKS007 Design of a Digital Controller for ALPI 80 MHz Resonators feedback, FPGA, controls, resonance 174
 
  • S.V. Barabin
    ITEP, Moscow, Russia
  • G. Bassato
    INFN/LNL, Legnaro (PD), Italy
  
  We dis­cuss the de­sign of a res­onator con­troller com­plete­ly based on dig­i­tal tech­nol­o­gy. The con­troller is cur­rent­ly op­er­at­ing at 80 MHz but can be eas­i­ly adapt­ed to fre­quen­cies up to 350MHz; it can work ei­ther in "Gen­er­a­tor Driv­en" and in "Self Ex­cit­ed Loop" mode. The sig­nal pro­cess­ing unit is a com­mer­cial board (Bittware T2-Pci) with 4 Tiger­Sharc DSPs and a Xil­inx Vir­tex II-Pro FPGA. The front-end board in­cludes five A/D chan­nels sup­port­ing a sam­pling rate in ex­cess of 100M/s and a clock dis­tri­bu­tion sys­tem with a jit­ter less than 10ps, al­low­ing di­rect sam­pling of RF sig­nals with no need of ana­log down­con­ver­sion. We pre­sent the re­sults of some pre­lim­i­nary tests car­ried out on a 80 MHz quar­ter wave res­onator in­stalled in the ALPI Linac ac­cel­er­a­tor at INFN-LNL and dis­cuss pos­si­ble de­vel­op­ments of this pro­ject.  
poster icon Poster MOPKS007 [0.931 MB]  
 
MOPKS020 Low Level RF Control System for Cyclotron 10 MeV controls, feedback, cyclotron, low-level-rf 199
 
  • J. Huang, D. Li, K.F. Liu
    Huazhong University of Science and Technology (HUST), Wuhan, People's Republic of China
  • T. Hu
    HUST, Wuhan, People's Republic of China
  
  The low level RF con­trol sys­tem con­sists of a 101MHz sig­nal gen­er­a­tor, three feed­back loops, an in­ter­lock and a pro­tec­tion sys­tem. The sta­bil­i­ty of con­trol sys­tem is one of the most im­por­tant in­di­ca­tors in the cy­clotron de­sign, es­pe­cial­ly when the whole sys­tem has a high cur­rent. Due to the huge­ness of the RF sys­tem and the com­plex­i­ty of con­trol ob­jects, the low level RF con­trol sys­tem must com­bine the basic the­o­ry with the elec­tron­ic cir­cuit to op­ti­mize the whole sys­tem. The major ob­sta­cles in the re­search, which rarely exist in other con­trol sys­tems, lay in the cou­pling of beam and res­o­nant cav­i­ty, re­quir­ing to be de­scribed by the trans­fer func­tion be­tween beam and cav­i­ty, the com­plex cou­pling be­tween mi­crowave de­vices and the in­ter­fer­ence sig­nals of all loops. By in­tro­duc­ing the three feed­back loops (tun­ing loop, am­pli­tude loop and phase loop) and test re­sults from some parts of elec­tric cir­cuits, this paper un­folds the per­for­mance index and de­sign of low level RF con­trol sys­tem, which may con­tribute to the de­sign of cy­clotron with a high and re­li­able per­for­mance.  
 
MOPMN016 The Spiral2 Radiofrequency Command Control controls, interface, EPICS, LLRF 274
 
  • D.T. Touchard, C. Berthe, P. Gillette, M. Lechartier, E. Lécorché, G. Normand
    GANIL, Caen, France
  • Y. Lussignol, D. Uriot
    CEA/DSM/IRFU, France
  
  Main­ly for car­ry­ing out nu­cle­ar physics ex­pe­ri­ences, the SPI­RAL2 fa­cil­i­ty based at Caen in France will aim to pro­vide new ra­dioac­tive rare ion or high in­ten­si­ty sta­ble ion beams. The driv­er ac­cel­er­a­tor uses sev­er­al ra­diofre­quen­cy sys­tems: RFQ, bunch­er and su­per­con­duct­ing cav­i­ties, driv­en by in­de­pen­dent am­pli­fiers and con­trolled by dig­i­tal elec­tron­ics. This low level ra­diofre­quen­cy sub­sys­tem is in­te­grat­ed into a reg­u­lat­ed loop driv­en by the con­trol sys­tem. A test of a whole sys­tem is fore­seen to de­fine and check the com­put­er con­trol in­ter­face and ap­pli­ca­tions. This paper de­scribes the in­ter­faces to the dif­fer­ent RF equip­ment into the EPICS based com­put­er con­trol sys­tem. CSS su­per­vi­sion and fore­seen high level tun­ing XAL/JAVA based ap­pli­ca­tions are also con­sid­ered.  
poster icon Poster MOPMN016 [0.986 MB]  
 
WEBHMUST02 Solid State Direct Drive RF Linac: Control System controls, experiment, software, LLRF 638
 
  • T. Kluge, M. Back, U. Hagen, O. Heid, M. Hergt, T.J.S. Hughes, R. Irsigler, J. Sirtl
    Siemens AG, Erlangen, Germany
  • R. Fleck
    Siemens AG, Corporate Technology, CT T DE HW 4, Erlangen, Germany
  • H.-C. Schröder
    ASTRUM IT GmbH, Erlangen, Germany
  
  Re­cent­ly a Solid State Di­rect Drive ® con­cept for RF linacs has been in­tro­duced [1]. This new ap­proach in­te­grates the RF source, com­prised of mul­ti­ple Sil­i­con Car­bide (SiC) solid state Rf-mod­ules [2], di­rect­ly onto the cav­i­ty. Such an ap­proach in­tro­duces new chal­lenges for the con­trol of such ma­chines name­ly the non-lin­ear be­hav­ior of the solid state RF-mod­ules and the di­rect cou­pling of the RF-mod­ules onto the cav­i­ty. In this paper we dis­cuss fur­ther re­sults of the ex­per­i­men­tal pro­gram [3,4] to in­te­grate and con­trol 64 RF-mod­ules onto a λ/4 cav­i­ty. The next stage of ex­per­i­ments aims on gain­ing bet­ter feed for­ward con­trol of the sys­tem and on de­tailed sys­tem iden­ti­fi­ca­tion. For this pur­pose a dig­i­tal con­trol board com­pris­ing of a Vir­tex 6 FPGA, high speed DACs/ADCs and trig­ger I/O is de­vel­oped and in­te­grat­ed into the ex­per­i­ment and used to con­trol the sys­tem. The de­sign of the board is con­se­quent­ly dig­i­tal aim­ing at di­rect pro­cess­ing of the sig­nals. Power con­trol with­in the cav­i­ty is achieved by an out­phas­ing con­trol of two groups of the RF-mod­ules. This al­lows a power con­trol with­out degra­da­tion of RF-mod­ule ef­fi­cien­cy.
[1] Heid O., Hughes T., THPD002, IPAC10, Kyoto, Japan
[2] Irsigler R. et al, 3B-9, PPC11, Chicago IL, USA
[3] Heid O., Hughes T., THP068, LINAC10, Tsukuba, Japan
[4] Heid O., Hughes T., MOPD42, HB2010, Morschach, Switzerland
 		 
slides icon Slides WEBHMUST02 [1.201 MB]  
 
WEPKS010 Architecture Design of the Application Software for the Low-Level RF Control System of the Free-Electron Laser at Hamburg LLRF, controls, software, interface 798
 
  • Z. Geng
    SLAC, Menlo Park, California, USA
  • V. Ayvazyan
    DESY, Hamburg, Germany
  • S. Simrock
    ITER Organization, St. Paul lez Durance, France
  
  The su­per­con­duct­ing lin­ear ac­cel­er­a­tor of the Free-Elec­tron Laser at Ham­burg (FLASH) pro­vides high per­for­mance elec­tron beams to the las­ing sys­tem to gen­er­ate syn­chrotron ra­di­a­tion to var­i­ous users. The Low-Lev­el RF (LLRF) sys­tem is used to main­tain the beam sta­bil­i­ties by sta­bi­liz­ing the RF field in the su­per­con­duct­ing cav­i­ties with feed­back and feed for­ward al­go­rithms. The LLRF ap­pli­ca­tions are sets of soft­ware to per­form RF sys­tem model iden­ti­fi­ca­tion, con­trol pa­ram­e­ters op­ti­miza­tion, ex­cep­tion de­tec­tion and han­dling, so as to im­prove the pre­ci­sion, ro­bust­ness and op­er­abil­i­ty of the LLRF sys­tem. In order to im­ple­ment the LLRF ap­pli­ca­tions in the hard­ware with mul­ti­ple dis­tribut­ed pro­ces­sors, an op­ti­mized ar­chi­tec­ture of the soft­ware is re­quired for good un­der­stand­abil­i­ty, main­tain­abil­i­ty and ex­tendibil­i­ty. This paper pre­sents the de­sign of the LLRF ap­pli­ca­tion soft­ware ar­chi­tec­ture based on the soft­ware en­gi­neer­ing ap­proach and the im­ple­men­ta­tion at FLASH.  
poster icon Poster WEPKS010 [0.307 MB]