De Metz-Noblat, N

Di Maio, F

Garoby, R

Gouber-Pace, M

Hancock, S

CERN Document Server

16 November 1995Geneva, SwitzerlandSystems, Chicago (U.S.A.), Oct. 29-Nov. 3, 1995ICALEPC1'5'95, Int. Conf. on Accelerator and Large Experimental Physics Controloperational principles which it has afforded. OCR OutputThis paper reviews the main advantages of the new equipment and the evolution in1 kl-Iz. New timing diagnostics have also been implemented.display of RF parameters by processing a wide variety of signals continuously sampled atsystems. In addition, a novel measurement scheme has been installed which provides adevelopments but also by changes in the philosophy underlying the operation of those RFhardware offers features which have been exploited not only by concomitant softwareof all components of the controls interface to the RF systems of the PS machine. NewThe latest upgrade of the control systems of the CERN PS Complex has seen the replacementAbstractN. de Metz·Nob1at, F. di Maio, R. Garoby, M. Gouber-Pace, S. HancockCONTROLS UPGRADE OF THE RF SYSTEMS OF THE CERN PSCERN/PS 95-43 (RFICO)CERN · PS DIVISIONfh J -OEUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH 9 r~.` NQM RSV- ’5f- M3 »— KF»COrestart pulse is received and processing of the vector table is resumed. This facility is used extensively to synchronise OCR OutputIn addition to more vectors, a function may contain multiple internal stops to hold the output at a certain value until a_ within the same machine cycle as variants of a common fundamental programme.convens the product of two such digital inputs. The latter permits different cavity voltage programmes to be generatedof the generated function either to a simple DAC for normal applications or, particularly, to a multiplier plus DAC whichtransmission of analogue signals over long distances, a galvanically isolated serial link carries the instantaneous digital valuesfrom a combinatorial philosophy which has, therefore, been extended in this particular case. In order to avoid thedetailed functions has thus been removed. However, the tremendous flexibility of the principal RF system of the PS derivesthe production of analogue signals. The need for extensive combinations of generators and summing amplifiers to provideNew VME·based function generators [Ref. 1] have increased by an order of magnitude the number of vectors available for2 .1 Function Generators2. HARDWAREFigure l: Basic RF layout.Acmmonamplitude, etc...)(Frequency, phase,MeasurementsRF goum Auxiliary SystemsB C OL O T¤¤i¤8 P°W¢1’ $¤PPb’ I \ scrvosPower Ampuaers<·¤¤¤s Tuning F Qgvfgms PV uaTimings & _| Q Signal Processing V (mageIIIIIIIIQIIIIIIIIIIIIIIIIIllllllllli .|IlIIlIIIIIIIIIi\.IlIIBeamLongitudinal Pick-ups Radial Pick-ups RF Cavities2 CAMAC and 21 G64 crates.parameters which are only refreshed once per machine cycle. ’l`he corresponding hardware comprises a total of 6 VME,variable are employed: analogue functions (RF voltage, servo loop gains, etc.); timing pulses; and bit patterns for quasi·staticFigure l is a greatly simplified schematic diagram showing the main features of a PS RF system. Three types of controlcomponents of the interface to the three RF systems of the machine.of the control system of the PS is foreseen in two stages, the first of which has been completed and has affected allyear old PS machine which handles a variety of particle beams on a cycle-to-cycle (so·called ”PPM") basis. A rejuvenationThe PS Complex comprises three linear accelerators and six circular ones, all interlinked. At its heart lies the thirty-six1. Irmtooucrrouafforded.This paper reviews the main advantages of the new equipment and the evolution in operational principles which it hasvariety of signals continuously sampled at 1 kl-lz. New timing diagnostics have also been implemented.addition, a novel measurement scheme has beeninstalled which·provides a display of RF parametersby processing a wideconcomitant software developments but also by changes in the philosophy underlying the operation of those RF systems. lncontrols interface to the RF systems of the PS machine. New hardware offers features which have been exploited not only byThe latest upgrade of the control systems of the CERN PS Complex has seen the replacement of all components of theAbstractPS Division, CERN, CH·I211, Geneva 23, SwitzerlandN. de Metz-Noblat, F. di Maia, R. Garoby, M. Gourber-Pace, S. HancockControls Upgrade of the RF Systems of the CERN PSM. Nonglaton and A. Ga, OCR Outputsupport of P. Maesen, 1.-P. Terrier and J.·L. Vallet. Important software conuibutions were made by A. Campbell, I.The successofthecontrolsupgrade oftheRFsystemsofthePS machineisdueinlargeparttotliededicated technical4. Acrmofaults [Ref. 8] is available to specialists.Any problems with the high·power RF systems of the machine are automatically logged so that a complete record of3.3 FaulrHistarytypes of er may be monitored and warnings are issued for acquisitions which are out of tolerance.system [Ref. 7] has been developed to measure time `difh key-signalswith a resolution of 1 ns. Eight differentTo this end, a transfer timing surveillance ('I'l'SM)neighbours and client machines for injection and extractionabove. However, it is insufficient to monitor the beam·related timings that are required to synchronize the PS with itsThe precision of the TSM m¢8SlIf¤D¢Ill is a consequence of its reliance on the widely-distributed 10 MHz clock describedsupercycle of the machine.including multiple ones, are recorded with a resolution of 100ns and an exhaustive list may be produced for an entiresurveillance (TSM) system [Ref. 6] has been developed to monitor simultaneously some 150 timing channels. All pulses,Among the most difficult tasks in the operation of an accelerator is the diagnosis of timing problems. A timing3.2 Timing SurveillanceFigure 3: Total detected voltage and corresponding harmonic number measurements.;—$E···· :;,3··:·:·i»i»¤-E‘-,;:§-*;i$··>:;&;‘ :·>··,§·:·:·:·:;§g;g-_;;‘;§&§;~g-:<·>:·:·>:·:·:»:·:-5E·E·$$!·¥_-§3§g;i·:·:~:·:·:»€·$§:·:·:~E·E-$$i·f·$b$:·:;g:q:y:;zg1;ax;;:;c;;:;5;;:;:;:;fgZ;&§;>·.-:::¢;azg;:;cgnwU.!2.••·.•s.•t..•1•-•um,MAas.•.?I\.\ anon{LOMJ.tt!Mal.._...,..,......._......... .,,.__,_.._t_____.....can be accessed for display or further treaunent.onic, of each principal cavity. Both the raw andthe ,withrespecttothcphasesumfortheappropriatesameharmonic(seeFigure3).Italsocornput¤sthetant voltazc and ts of the principal RF sysm by summing vectmially over all cavities which are onbleduringtlte&timeattheexidofacyclef¤ byanadditiomlreal·timetak[Ref.S]whichcomputesare madeanddetected cavity voltages.buofeach ofthose cavities;andofa1l' of theselected RF &equenci¤: of the phase, with rmect to a revoludon hequency reference. of each of the principal RF cavities:on which the MTG is sym Various real-dme mb coouol the acquisition of the beam revolution bequency andrheacdvepanofcvexymachinecyclc. The lklizmmphngbequemyiswivedbom mhemme oscillatorbledwhich¤0videsam¤ur¤ncu¢0ftl1e¤e¤tia1RF eachApowufuldijralsysaunhas3.1 Smnplcd RF MemuremmtsOCR Output3. D1A0N0s‘r1csPS Complex equipment". ICALEPCS‘95 in these[81 M. Beharrell. G. Benincasa, J.-M. Bouché. I. Cupcms. M. Lelaizmt. L. Ménrd, 'Model-based, detailed fault analysis in the CERN'Nctc 93-20 (1993).[7] S. Payaud, "`l191-07 (1991).[61 P. Bobbio. 'Ti[5] A. Campbell, "ReaI-zine formulae pucessing tak for the PS 10 MH: cavity measurement system'. CERN/PS/RF/Note 95-28 (1995). .ent in the PS". CERN/PS/RF/Note 95-12 (1995).[4] P. Maesea, "'Ihe G64 interface used no euntml theTsukuba (1992). p. 360.ez Tg8", in Pmc. ICALEPCS '91, KEK Pmc. 92-15, KEK. ,,[31 G. Beetham. G. Daeuu, I. Lewis. B. Puecio. "A newAss: (1994). p. 91., Oct. 18-23, 1993. Nucl. Instr. and Meth., ICA.LB'CS,[2] I. Lewis, V. Siknlenkn. *1}: new EN PSg¤1en¤·", Internal Note 93-09 (Tech.) (1993).[11 W. Heine, R. Maccsferri, "GFAS: s new simple5.

Controls upgrade of the RF systems of the CERN PS

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