< kazuro.furukawa @ kek.jp >Simultaneous Injections to KEKB and PF
and Event-based Control System
Kazuro Furukawa< kazuro . Furukawa @ kek . jp >For Linac Commissioning Groupand for Linac and KEKB Control Group
February 2010.
Simultaneous Injection

Kazuro Furukawa, KEK, Feb.2010.

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Electron Accelerator Complex
Linac clients
KEKB
8-GeV e– 1nC x2
3.5-GeV e+ 1nC x2(with 10nC primary e–)

PF 2.5-GeV e– 0.1nC
 PF-AR 3-GeV e– 0.2nC

At first simultaneoustop-up injections to three rings at KEKB and PF
Switching beams at 50HzFor stable operation and higher quality exp. results
Simultaneous Injection

Kazuro Furukawa, KEK, Feb.2010.

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KEKB Operation Improvement

Apr.2003
Dual Bunch e+May.2000

Feb.2005
ContinuousInjections
Simultaneous Injection

Kazuro Furukawa, KEK, Feb.2010.

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KEKB Injections
during Beam Studies at PF and PF/AR

Simultaneous Injection

Kazuro Furukawa, KEK, Feb.2010.

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Motivation
Was suggested since 2004

Luminosity degradation on beam studies at PF andPF/AR
Future SuperKEKB injections with shorter lifetime
Sensitive luminosity tuning with Crab cavities
PF top-up injection for higher quality experiments
CERN/PS switches beams every 1.2s (PPM)SLAC/SLC switched beams at 180 Hz
KEK Linac had switched beams 360 times a day in 2008,
10~120seconds per switching
Simultaneous Injection

Kazuro Furukawa, KEK, Feb.2010.

5Requirements
Maximum beam rate of 50Hz x 2bunches should bekept
Most pulsed power supplies were designed tooperate at constant rate
Most Linac magnets were not pulsed (exceptpositron focusing)Thus, it took much time for standardization

Approx. 1000 devices in Linac
600 active devices (gun, RF, magnets, etc), 100 passivedevices (BPM, WS, etc), and static devices

No resources for separate linac
20ms beam switching became the solution
At first HER/PF, later HER/LER/PF

Simultaneous Injection

Kazuro Furukawa, KEK, Feb.2010.

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Hardware and Operation Improvements
Separate BT for PF (2005)
Pulsed bending magnet for PF (2007)
PF beam from common gun (A1) (2007)
Beam charge safety interlock (2007)
Event-based fast control system (2008)
Pulsed steering magnets (2008)
Electron bypass hole at positron target (2008)
Interface between ring-linac RF (2008)
Multi-energy linac optics (2008)
Simultaneous injections (Apr.2009)
Simultaneous Injection

Kazuro Furukawa, KEK, Feb.2010.

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Fast Controls
~100 parameter switching within 20ms
Keep most of magnet fields with compatible optics
Control llrf to change energy

Pulsed magnet triggers and delays
Delays to keep the constant rate for certain power-supplies

LLRF phases and delays
Gun voltage and fine delay
Interface to bucket selection, etc
Ethernet-based controls are not reliable enough
FPGA and fiber-optic RocketIO might be the way ?
Simultaneous InjectionKazuro Furukawa, KEK, Feb.2010.

8Event System
Many accelerator system require timing signals andaccompanying information (event) Several primitive facilities are combined and used at KEKB and Linac
 Fast Timing signals are provided with delay module TD4/TD4V
 Need timing trigger and rf clock (Slow) Events are provided in another facility Combining Hardware and Software Event/Timing Systems which distribute the both timing and event aredeveloped at Argonne/SLS/Diamond, and are employed at manyinstitutes (Event Generator/Receiver) Fast Timing, rf clock, Hardware event, Software Interrupt, can be handled
in one combined system with a single fiber cable Especially in EPICS, event can be connected EPICS Event directly, sorecord/database programming is possible
RfTrigger

Eventgenerator

Simultaneous Injection

Event code

FanoutEvent receiver
Event receiver
Event receiver

Output/Input

Optical fiber link
Kazuro Furukawa, KEK, Feb.2010.

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Timing System

Old Timing Station

Simultaneous Injection

New Event Receiver Station
with 16 outputs

Kazuro Furukawa, KEK, Feb.2010.

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Event System
Simultaneous Injection
to KEKB-HER, KEKB-LER, and PF
2.5GeV to 8GeV, 0.1nC to 10nC

Stable stored beam current at three rings
Should improve collision tuning with Crab cavities
Should improve the quality of experimental data at PF

Fast switching of many device parameters
In 20ms / 50Hz
Should be reliable because beam power is much different

MRF Series 230 Event Generator / ReceiverVxWorks 5.5.1, MVME5500 (Originally with RTEMS but…)
Timing precision less than 10ps is sufficient (TD4 provides 3ps)
Multi-mode fiber, and single-mode fiber for longer distance

Simultaneous Injection

Kazuro Furukawa, KEK, Feb.2010.

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Event System Configuration
 MRF’s series-230 Event Generator / Receivers
 VME64x and VxWorks v5.5.1
114.24MHz event rate,
 EPICS R3.14.9 with DevSup v2.4.1
50Hz fiducials
 17 event receivers up to nowMore than hundred
50Hz-Analog/Timing data
Multi/single-mode fiber
Timing precision is < 10ps.
 < 1ps with external module.

Simultaneous Injection

Kazuro Furukawa, KEK, Feb.2010.

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Synchronization Scheme
Synchronization Req.

for PFKEKB : < 30ps
PF : < 300~700ps

Linac SHB
114.24MHz
PFCircumferenceCorrection

Flip-flop
Flip-flop

PF Revolution
1.6 MHz

Flip-flop

50Hz

EventSystem

Linac rf isSynchronized to KEKB rf
Event Clock is114.24MHz
We have to manage

AC Line Sync.

BucketSelection

EventSystem

for KEKB

Clock
Fiducial
114.24 MHz

SHB1 Phase
Controlx5
RubidiumSG

10 MHzHER/LER
Injection
Phase Control

571.2 MHzSG

x52856 MHz
X 49 ÷ 275

KEKB HER/LER
Circumference
Correction

508.89 MHz

Acc. Phase,
Timing Control

508.89 MHz
HER/LER
BucketSelection

Simultaneous Injection

SHB2 Phase
ControlCircumferencecompensation
Bucket selection
Injection phase controls

÷ 512099.39 kHzKEKB RevolutionKazuro Furukawa, KEK, Feb.2010.

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Beam Mode Pattern Generation
Pulse 1

Pulse 2

Pulse 3

Beam Mode 1

Beam Mode 2

Beam Mode 3

Pulse n………

Beam Mode nMain eventcodes for ʻnʼPreparation eventcodes for ʻn+1ʼ

 Every pulse (every 20ms) corresponds to a beam mode 10 different beam modes are defined (for KEKB e+, etc)
 One beam mode may contain several event codesAt least one main code and a preparation code for the next pulse

 About 50 event codes are definedSome events correspond to many functions, and others to specific devices

 Beam pattern buffer length (n) can be 2 to 500 (20ms x 500 = 10 seconds)
 A new pattern can be loaded at the end of the previous pattern Otherwise, the pattern repeats forever.

 Main events and preparation events in sequence Main events trigger timing signals
 Preparation events trigger software to exchange analog and delay parameters
Simultaneous Injection

Kazuro Furukawa, KEK, Feb.2010.

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Beam Mode Pattern Generators
 Pattern panel arbitrates requests
 From downstream rings with priorities, or human operators
 There are several pattern rules due to pulse device features andlimitations
 Pattern arbitrator software was written in scripting languages to meet
daily changes during the commissioning stage
Remote controlled automatic pattern arbitrator

Manual pattern generator

Typical operation in 2009.
~25Hz for KEKB LER
~12.5Hz for KEKB HER
~0.5Hz for PF
Simultaneous Injection

Kazuro Furukawa, KEK, Feb.2010.

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LLRF
LLRF Timing/analog signals are essential for absolute energy,
energy spread, and dual-bunch energy equalization
Signals are switched pulse-by-pulse
Value changes are triggered by a preparation eventDriver klystrons (SB), energy tuner klystron (KL), andsub-harmonic bunchers (SH) are managed
by the event system

Simultaneous Injection

Kazuro Furukawa, KEK, Feb.2010.

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BPM
Tektronix DPO7104 can acquire data at >50Hz.
With embedded EPICS

Beam modes are recognized by events through CA network.
Clients can monitor data of an interested beam mode.
26 oscilloscopes are installed.
100 BPMs are synchronized. (100 BPMs at BT as well soon)

Simultaneous Injection

Kazuro Furukawa, KEK, Feb.2010.

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Measurement and Data Acquisition
Originally much efforts to develop
detectors, shaping amplifiersNo budget for all BPMs

Switched to direct waveform acquisition
Minimized active components, thenminimized calibration tasks, maintenanceEqual-length cables
One oscilloscope covers about 5 BPMs, orcombined 20 (or 40) waveforms
5 - 10Gs/s (with additional interpolation)
Possible to measure dual bunches
Solved many issues at once!
Extract each signal, apply calibration factors,
send to upper layer at 50Hz

Simultaneous Injection

Kazuro Furukawa, KEK, Feb.2010.

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Embedded IOC on OscilloscopeDPO7104, 10Gs/s, 4ch, 8bit
Windows-XP
Cygwin software development environment
Microsoft Visual C++ 2008http://www-linac.kek.jp/cont/epics/win32/

EPICS 3.14.8.2
Fast data-acquisition at ~150Hz was tricky, but waspossible
Event triggers the data acquisition
Beam positions and charges are calculated based on ~30
coefficients, and tagged with beam modes
50Hz processing is stable at Linac
Very efficient for us
Simultaneous Injection

Kazuro Furukawa, KEK, Feb.2010.

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Parameters
Parameters switching via Event system
LLRF phase/timing : 14x4
HP RF timing : ~60
Gun voltages, picosecond delay : 4
Pulsed magnets/solenoid : 14
Injection phase : 2
Bucket selection : 2
BPM : ~100x3

Basically sufficient for fast beam mode switchingMore parameters comming
Integrity monitors
Improved slow beam feedback, fast feedback, etc.
Simultaneous Injection

Kazuro Furukawa, KEK, Feb.2010.

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Linac Event System
Satisfies the requirements

CPUEvent rate : 114.24MHz (bit rate : ~2.3GHz)
Fiducial rate : 50Hz
Timing jitter (Short term) : ~8ps
No. of defined events : ~50
No. of receiver stations : 17
No. of Fast parameters : ~130
CPU stopped 4 times
since Sep.2008
for 18 stations
Simultaneous Injection

EVG
EVR
Opt. Fan-out

EVR & LLRF

Kazuro Furukawa, KEK, Feb.2010.

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Beam Current
Beam currents
are kept withinKEKB 1mA (~0.05%)
PF 0.05mA (~0.01%)

Simultaneous Injection

Kazuro Furukawa, KEK, Feb.2010.

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KEKB Operation Improvement
Belle/KEK

May.2000
Apr.2003
Dual Bunch e+Feb.2005
ContinuousInjections
Dec.2008
Crab Cavities andSimultaneous Injection
Simultaneous Injection

Kazuro Furukawa, KEK, Feb.2010.

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SummarySimultaneous injection to HER/LER/PF wassuccessfulDevelopment and installation for various kind of hardware
Another layer of controls based on a fast event system
Pulse-to-pulse reprogramming of event system

Beam optics diagnosis down to ~1%More integrity monitors may be necessary for longer termNeed for consideration on PF-AR injection
ex. 4-GeV positrons for PF-AR (?)

Simultaneous injection
will be the base for SuperKEKB as well
Simultaneous Injection

Kazuro Furukawa, KEK, Feb.2010.

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Thank you

Simultaneous Injection

Kazuro Furukawa, KEK, Feb.2010.

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