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STATUSC. Hovater

Abstract To support t

12 GeV, the Rcontrol the hcavities. Eightsupport the uheterodyne trmeasure and Altera FPGA control algoritdigital self exLorentz detunisuccessfully cnow moving inpaper discussproduction of peripheral syscontrol).

In the nextincrease its finaccomplish thbeing construcnew cavity approximatelyspecification cryomodules, klystrons to bebeing moderniIn addition othresonance conhigh power amtake advantage

The new cdetuning) thatgradient cavitsquare of thedetuning approgradient to thecavity we useprogrammed inthe control sysResonator (GDspeed of the switch from SE

The field cmodern LLRF ______________* Notice: AuthoreDOE Contract Nretains a non-excpublish or reprodu

S OF THEr, T. Allison

the CEBAF enRF control syshigh gradientty new LLRF

upgrade. The ransceiver aloncontrol magniis used to di

thms. One of thxcited loop to ing (800 Hz) ducompleted prelnto the producses the desigthe new RF cstems (cavity

INTRODt two years tnal beam energhis, 10 new eigcted. To meet

will have y 20 MV/m. W

remains uncthe higher

e purchased. Tized by going her aspects of ntrol system, thmplifier controe of technologycavities pose t have not beeties. Since Loe gradient theoaching 800 He operating gre a self excitento the firmwastem is switchDR) controllercavity fill timEL to GDR, ~

FIELD Ccontrol systemF design wit________ ed by Jefferson SNo. DE-AC05-06clusive, paid-up, uce this manuscrip

E CEBAF n, R. Bachim

Jefferson

nergy upgrade stem is being t high QL suF systems are

new system ng with I&Qitude and phagitally implemhe features of

track the cavuring turn on. liminary develtion stage of thgn, modeling

control system interlocks,

DUCTION the CEBAF agy from 6 GeVght cavity cryt the increased

an average While the overa

changed for gradients req

The RF controlto a digital bathe RF system

he cavity interoller have beeny advances.

some challeen seen operaorentz detunine new cavitiesHz or 16 bandradient. To quied loop (SEL)are [1]. Once bhed back to Ger. The recover

me plus the ti10 ms.

ONTROL m architectureth one large

Science Associates6OR23177. The

irrevocable, worlpt for U.S. Govern

ENERGYmanchi, G. Lan Lab, Newp

from 6 GeV tomodernized to

uperconductingbeing built toincorporates

Q sampling tose. A low-cos

ment the cavitythe system is

vity over largThe system halopment and ihe project. Thi

g, testing andand associated

and resonanc

accelerator wilV to 12 Gev. Toyodmodules ard energy, each

gradient oall field contro

the upgradquire 13 kWl system is alsoased controllerm including thrlocks, and thn redesigned to

enges (Lorentating the loweng goes as ths may have

dwidths, from 0ickly recover that has been

back at gradienenerator Drivenry speed is thime it takes to

e is a typicaFPGA board

s, LLC under U.SU.S. Governmenld-wide license toment purposes.

Y UPGRADahti, J. Mussort News Vi

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as is is

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of ol de W

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tz er e a 0

a n

nt n

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al d

(digital) cchannels afield contcontrol sywhich als(IOC). Into interfacpower afeedback

The tra

1497 MHMHz (whusing 16 the field ra dynamichannel ireflected pall other cfrom the other freqboard.

The dalgorithmreference generate aFPGA. Uthe in-phsignal fofirmware.a 14 MHalso prodamplified also has aand 4 mdiagnosticcontrol al16-bit AD

.to

DE RF COson, T. Plawirginia, 2360

connected to aand one transmtrol chassis (Fystem is throuso acts as thn addition the ce to other systamplifier, maand timing con

Figure 1: F

ansceiver boarHz, down to an hich is a legacybit ADC’s. 16regulation specic range requsolation is 60 power and 70 dchannels. Sincdigital board quencies whil

digital board ms using an Alte

is fed to an oa 56 MHz cloc

Under-samplinghase and quador digital sig. The DAC ch

Hz sine wave wduces a 70 MH

for use as tha 1 Msps 16-bimore DAC chc DACs havelgorithm signalDC used to m

ONTROLski, C. Seato

06

a transceiver bmitter channel)FCC). The inteugh an off the e EPICS Inpuchassis has nutems (e.g., reso

achine protectntrol).

Field Control C

rd converts thintermediate f

y frequency). 6 bit ADC’s arcification (0.5o

uirement of 2dB between

dB between cae the transceivthe digital boa

le only chang

implements era Cyclone IIIn-board phase

ck that drives tg the 70 MHz I

drature (I&Q) gnal processinhannel uses I&Qwith a 56 MHHz component e cavity driveit DAC used tohannels for de proven usels during deve

measure the lo

L SYSTEMon, D. Seidm

board (four rec. Figure 1 show

erface to the Eshelf PC104

ut-output contumerous I/O sonance controltion, beam

Chassis

e cavity frequfrequency (IF) The IF is dig

re necessary too and 4.4x10-4)20 dB. Channforward powe

avity transmittever board is separd can be use

ging the transc

the field cI FPGA. A 70

e lock loop (PLhe ADCs, DAIF at 56 Msps components o

ng by the FQ values to genz update rate.that is filtere

. The digital o drive a piezodiagnostics.

eful for monilopment. A 1

ocal oscillator

M * man

ceiver ws the EPICS board troller ignals l, high based

uency, of 70

gitized o keep ) over nel to er and ed and parate ed for ceiver

ontrol 0 MHz LL) to C and yields of the FPGA nerate This

ed and board

o tuner These toring Msps (LO)

MOP095 Proceedings of Linear Accelerator Conference LINAC2010, Tsukuba, Japan

280

03 Technology

3D Low Level RF

pfb

cfHaqWbtordcc

cmctrff

mdtmit

(a

piFc

power and twfuture applicatbuffer wavefor

REWith the hig

challenge for fault. The cavHz from an accelerators hquickly adjust We intend to back to the opto the referencof helium driftreference. Thedetuning, a stecryogenic tripscan cover +/- 2

The field ccontrol with dmode, the FCCcavity transferthe reference. recovering cavfrequency disfirmware) prov

The steppemotors. It usedriver (US Digthe stepper motherboard ainformation is the FCC. Figur

Figur

The PZT a(PA69) normaamplifier can p10 Hz, full sprovide approxis controlled bFigure 3 showcards.

wo more ADCtions. SDRAMrms of importa

ESONANCgher gradients an RF system

vity with zero operational gr

have employethe cavity as tuse a self exc

perational gradce. A PZT willts and keep thee PZT tuning repper motor ws and long main200 kHz. control chassisdetuning inforC will provider function phas

When the FCvities detunedscriminator (vides tuning iner motor chaes an off the gital MD2S). Lchassis uses

and a PC104 delivered throre 2 shows the

re 2: Stepper m

amplifier incoally used forprovide 150 Vscale. Typicallximately 20 V y the FCC usin

ws the PZT ch

C channels areM is used for capant signals for d

E CONTROthe new cryom

m to recover cgradient mayb

radient of 20 d a Piezo tuthe gradient is cited loop to bdient and then l be used to m

e cavity frequenrange is 2000 will be used tontenance down

s will supply rmation. Whene the tuners wie to keep the cCC is in SEL

d more than aa byproduct

nformation. ssis controls shelf micro-s

Like the field a custom

EPICS IOC. ough the contro

stepper motor

motor control ch

rporates an Ar printers and

V/30 mA with ly the systemat 10 mA at 1

ng one of its 0hassis and one

e available fopturing circuladiagnostics.

OL module poses cavities after be detuned 800

MV/m. Otheuner (PZT) toramped up [2]

bring the cavitylock the cavity

minimize effectncy close to thHz. For large

o recover fromns. The steppe

the resonancn in the GDRith a traditionacavities close toL mode and ia bandwidth,

of the SEL

eight steppestepping motocontrol chassiFPGA basedCavity tuning

ol network fromr chassis.

hassis

Apex amplified copiers. Tha bandwidth o

m will need to0 Hz. The PZT

0-10 vdc DACse of the drive

or ar

a a 0

er o ]. y y ts e

er m er

e R al o is a L

er or is d g

m

er he of o T s. er

The supprotectioninterlockspresent CE

F

Interlock

Arc

Infrared

WaveguiVacuumBeam LinVacuumQuench

The cav

tube moucryomoduwindow. μs to 10mThe arc using an Lis turnedview the sensor voup to triggalso automline vacuappropriainterlocks

CAVITYperconducting n interlocks. Ts. The interloEBAF cryomo

Figure 3: Piezo

Table 1k De

Ph

Th

ide Ion

ne Ion

Grcha

vity arc detecunted at a poinule such that The arc trip w

ms. Typically thdetector is c

LED. Any maloff. There arwarm and co

ltage is recordger a fault. Likmatically testeuum space is te trip settings

s are internall

Y INTERLOcryomodule re

Table 1 shows cks are simila

odules.

o Tuner amplif

: Cavity Interloetection

oto-multiplie

hermopile

n Pump

n Pump

adient rate ange FCC

ctor consists ont on the wavit can view t

window can be ahis is set for a continuously tlfunction is repre two IR deteold waveguideded cold and thke the arc detecd. Both the wmonitored wi

s established. ly developed

OCKS equires a numbthe different c

ar to what is o

fier chassis

ocks System

r Interlock chassis Interlock chassis Interlock chassis Interlock chassis FCC

of a photomultveguide enterinthe cold waveadjusted betwetrip point of 50ested automat

ported and the cectors positione windows. Thhen a set point ctor, the IR sen

waveguide and ith ion pumpThe quench anin the FCC.

ber of cavity on the

tiplier ng the eguide een 10 00 μs. tically cavity ned to he IR is set

nsor is beam s and nd RF . The

Proceedings of Linear Accelerator Conference LINAC2010, Tsukuba, Japan MOP095

03 Technology

3D Low Level RF 281

qc

bi

ib

cifa(t

cHecf

WoQctont

tiat

quench is a rcavity field lev

An interlockbeing designedin a cryomoduscreen interfacinterface betwbe a fiber link,

As part of scontrol chassiinstalled in thefor the field coall RF receive(analog, digitatest stand.

Once the RFchassis they wHere the receiensure precisechassis is thenfeedback contr

Figure 4: Di

REWe have bee

system for coWhen cavitiesof performancQo, tuning rancavity microthresholds. In of test equipmnew LLRF systhe test equipm

To this end the new RF information is a PLL-VCO tothe cavity. Wit

rate of changevel. k chassis, simild and will activule. An additice for local c

ween the interlo, to quickly shu

TEST System quality is will be rige accelerator. Inontrol, a bed-ofr ADCs, transm

al, optical). Fig

F and digital bwill be tested inivers are calibre gradient accun tested arounrol can be chec

igital board “be

ECENT CAen exploring thmmissioning t

s are delivered ce tests are mange, tuner hy

ophonics, quethe past this h

ment, typically stem it may be ment and autom

we recently tsystem for scritical for op

o determine thth the new sys

e detector tha

lar to the steppvely monitor aional feature wcontrol and mock chassis andut down the RF

STANDS control, each b

gorously testedn the case of thf-nails test willmitter DAC angure 4 shows t

oards are maten the field conrated using a puracy during ond a cavity emcked and gains

ed of Nails” tes

AVITY TESThe concept of uthe superconduto the acceler

ade. These teysteresis, maxiench and fhas required nuoperated manupossible to eli

mate these teststested the feassuch measurem

perations. In thee mechanical t

stem, operating

at monitors th

per controller, iall eight cavitiewill be a touch

monitoring. Thd the FCC wilF.

board and fieldd before beinghe digital boardl be used to tesnd all other I/Othe bed of nail

ed together in ntrol test standpower meter tooperations. Thmulator so thaset.

st stand

TS using the LLRFucting cavitiesrator, a numbests include QLimum gradientfield emissionumerous pieceually. With thminate some o

s. ibility of usingments. Tuninge past one usedtuning range og in SEL mode

e

is es h e ll

d g d st O ls

a d. o

he at

F s. er L, t, n

es e

of

g g d

of e,

the tuner range meindicate similarly PZT. Tunshows the

Figure 5: of the detand forth

Other musing a ploaded Qsinternallywaveforminternally

Figure 6:power. horizontalCavity gra

We prototypeLorentz implemensystem hathree yearand has specificatflexibilityThe new than the ocommissi10 new R

[1] C. HAcceAlbu

[2] M. CompPAC

[3] C. HoCavit2008

can be swept seasured. Ththe exact stobe measured fning resolutione tuning resolut

Field Control ectable tuning in 1 Hz steps u

measurements pulsed RF systs can be measu by the RF con

m of the cavpulsed by the

: Pulsed wavThe vertical

l is samples adient was 7 M

SUhave succ

/development detuning a d

nted to recoveras been tested ors. Field cont

met the rtion [3]. The ny and better dia

LLRF systemolder analog cooning is sched

RF zones will b

REFHovater et al, “

lerating Cavquerque USA,

Liepe et pensation wit’01, Chicago Uvater, “RF Conties”, LINAC’, WE105

stop to stop andhe frequency op frequencyfor both the sten is better thtion with the R

Chassis diagnresolution. Ca

using the stepp

such as cavitytem. From theured using the wntroller. Figureity transmitteLLRF system.

eform of the scale is ADwhere one s

MV/m.

UMMARY cessfully tr

to productiodigital SEL ar faulted cavitieon numerous ctrol has been required ampnew digital RFagnostics than

m will also beontrol system. duled to begin be operational b

FERENCES“A Digital Selvity Field C

June 2007, Wal, “Dynami

th a Fast PieUSA, June 200ntrol of High Q’08, Victoria

d the completediscriminator

. Hysteresisepper motor an

han a Hz. FigRF system.

nostic output (Davity was tunedper motor.

y QL are easilye cavity decay waveforms acqe 6 shows the pd power that.

cavity transmDC counts an

ample is 1.17

ransitioned on. To overalgorithm is es quickly. Thcavities over thtested to 20 M

plitude and controls will the present sy

e easier to maRF and cryomsummer 2011

by 2013.

S lf Excited LooControl,” PA

WEPMS065, p. 2ic Lorentz ezoelectric Tu1 QL SuperconduCanada, Septe

e tuner r will s can nd the

gure 5

DAC) d back

made time,

quired pulsed t was

mitted d the 7 ms.

from rcome being e new he last MV/m phase allow

ystem. aintain

module 1. All

op for AC’07,

2490. Force uner,”

ucting ember

MOP095 Proceedings of Linear Accelerator Conference LINAC2010, Tsukuba, Japan

282

03 Technology

3D Low Level RF