New Event-based Control System
for Simultaneous Top-up Operation at KEKB and PF
K. Furukawa, M. Satoh, T. Suwada, T.T. Nakamura - High Energy Accelerator Research Organization (KEK)
T. Kudou, S. Kusano, T. Nakamura - Mitsubishi Electric System and Service (MELCO SC)
Artem Kazakov - Graduate University for Advanced Studies (SOKENDAI)
The 8-GeV linac at KEK provides electrons and positrons to three ring
accelerators of KEKB-HER, KEKB-LER and Photon Factory. Simultaneous
top-up injections to those rings are carried for the ultimate experimental results
at the both KEKB and PF facilities. An event-based fast control system wasnewly constructed overlapping the existent EPICS control system. The newsystem controls the distant equipment globally utilizing event modules fromMRF and several other techniques. The event system enables fast controls
from pico-second to milli-second range, and the conventional EPICS systemcovers slower controls. More than 100 parameters are driven globally by theevent system every 20ms pulse in order to generate beams with three-times
different energies and 100-times different charges. And more than 500
parameters are observed synchronously to ensure the beam operation. The
system enables the future accelerator complex such as SuperKEKB as well.
This paper describes the detailed design of the hardware and software
structures, beam operation experiences, and possible extensions towards thefuture.

Global and Synchronous Controls for more than 100 Parameters at 50Hz
and Sucessful Simultanenous Top-up Injections to Three Rings
Event System Configuration

Event SystemCPU◆ MRF series-230 Event Generator / Receivers.

EVGEVR◆ Multi-mode and single-mode fibers.

Event GeneratorCentralOpt. Fan-out◆ VME64x standard and VxWorks v5.5.1.
◆ 114.24MHz event rate,50Hz fiducials.

◆ 17 event receivers for now.
◆ Timing precision is better than 10ps.

SH_A1
KL_B5/B6

SB_B

SB_Ae­ GunARC◆ More than 100 50-Hz Analog/Timing points

Injectione– BT (PF: 2.5GeV, 0.1nC)

Cont-ABC

Beam Mode Pattern Generation

KL_51/52
SB_C

SB_1

SB_2

SB_3

SB_4

e+ BT (KEKB: 3.5GeV, 2nC)

SB_5

Pulse 1

Pulse 2

Pulse 3

Beam Mode 1

Beam Mode 2

Beam Mode 3

e+ Target
Cont-1

Cont-2

Cont-3Cont-4Cont-5e– BT (KEKB: 8GeV, 2nC,Pulse n………

Beam Mode n

PFAR: 3.0GeV, 0.1nC)

Event Receivers◆ Every pulse (every 20ms) corresponds to a beam mode.
◆ 10 different beam modes are defined (for KEKB e+ , etc).
◆ One beam mode contains several event codes.
◆ Beam pattern buffer length (n) can be 2 to 500 (20ms x 500 = 10 seconds).

RF Synchronization◆ A new pattern can be loaded at the end of the previous pattern.

EventSystemfor KEKB

◆ Otherwise, the pattern repeats forever.
◆ Pattern generator software arbitrates requests from downstream rings.

Clock◆ There are many pattern rules due to pulse device features and limitations.

Fiducial

SHB1 Phase
Control

114.24 MHz

Remote controlled automatic pattern arbitrator

Manual pattern generator / monitor

x5

Rubidium SG

KEKB
HER/LER
Circumference
Correction

10 MHz

SHB2 Phase
Control

571.2 MHzHER/LER
Injection Phase
Controlx5

SGAcc. Phase,
Timing Control

2856 MHzx 49 ÷ 275

508.89 MHz

508.89 MHz

÷ 5120HER/LER
BucketSelection

99.39 kHzKEKB Revolution

KEKB HER/LER Beam current history

for PF◆ Automatic injection program (or human operator)
Linac SHB
114.24 MHz

PF
Circumference
Correction

may change the beam mode pattern request
Flip-flop
Flip-flop

PF Revolution
1.6 MHz50Hz

several times a minutes

EventSystem◆ Typical operations at April-June 2009 was

AC Line Sync.

Flip-flop◆ KEKB HER 0~12.5Hz

BucketSelection◆ KEKB LER 0~25Hz◆ PF 0~0.5Hz◆ As stable operation was achieved,

the rates will be lower in the automn run.

Beam Instrumentation

LLRF Controls
Fiber

Event

Event
Receiver

DAC

ADC

VME
VxWorks
EPICS

Event

AnalogTimingllrf

Ethernet/CA

Oscilloscopewith Windowsand EPICS

Position&Charge
Beam mode◆ Timing and analog signals are essential for absolute energy,energy spread, and dual-bunch energy equalization.
◆ Signals can be switched pulse-by-pulse at 50Hz.
◆ Driver klystrons (SB), energy tuner klystrons (KL), andsub-harmonic bunchers (SH) are managed.

◆ The system successfully runs since summer 2008.
◆ Simultaneous injections are carried for 3 rings.
◆ Beam current stabilities (as of June 2009)◆ KEKB HER / LER : within ~1mA

BPM x 4~6
◆ Slow rf controls were replaced with fast event systems.

Summary◆ Tektronix DPO7104 with embedded EPICS

can acquire data at 50Hz.
◆ Beam modes are recognized by events through network.
◆ Positions and chargs are calculated with corresponding

calibration factors.
◆ Clients can monitor data of an interested beam mode.
◆ 100 BPMs covered by 24 oscilloscopes are synchronized.

for 1100~1600mA (at 12.5 - 25Hz)◆ PF ring : within ~0.05mA

for 450mA (at 0.5Hz)◆ It helped luminosity tuning with crab cavities.
◆ It should be the basis of SuperKEKB design.
◆ Will be further improved◆ Integrity monitor system◆ Beam and equipment monitor system