Upgrade of KEK Electron/positron Linac Control System
for the both SuperKEKB and Light Sources
K. Furukawa, Y. Enomoto, H. Kaji, H. Katagiri, M. Kurashina, K. Mikawa, T. Miura,
F. Miyahara, T. Natsui, I. Satake, M. Satoh, Y. Seimiya, H. Sugimura, T. Suwada
High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki, 305-0801, Japan
KEK injector linac has delivered electrons and positrons for particle
physics and photon science experiments for more than 30 years. It is being
upgraded for the SuperKEKB project, which aims at a 40-fold increase inluminosity over the previous project of KEKB, in order to increase ourunderstanding of flavour physics. This project requires ten-times smaller
emittance and five-times larger current in injection beam from the injector.
And many hardware components are being tested and installed. Even during
the 6-year upgrade, it was requested to inject beams into light sources

storage rings of PF and PF-AR. Furthermore, the beam demanding
approaches from those storage rings are different. SuperKEKB would
demand highest performance, and unscheduled interruption may be
acceptable if the performance would be improved. However, light sources
expect a stable operation without any unscheduled break, mainly because
most users run experiments for a short period. In order to deal with the both
requirements several measures are taken for operation, construction andmaintenance strategy including simultaneous top-up injections.

e– / e+ Injector linac upgrade with high-intensity and low-emittance beams
towards 40-times higher luminosity in SuperKEKB, as well as PF and PF-AR light sourcesSuperKEKB Electron/Positron Complex

Balanced Schedule for Improvements / Stability
Typical Accelerator Units

Pulse-to-pulse modulation operation

Positron generator and its shield

SuperKEKB particle physics

Injector Linac and Storage Rings

PF / PF-AR photon science◆ Long-term and fixed users◆ Short-term in many groups◆ Performance intensive◆ Stability intensive(Integrated performance)(Hates failures)◆ Minimum preventive maintenance◆ Deliberate scheduled maintenance◆ Invests on improvements◆ Invests on maintenance◆ May share common goal with users◆ Distance from users◆ Everyday is new◆ Fixed procedures

On-the-job training for operators

Difficult to train operators

Synchronized Global Controls

Many Devices with Pulsed Operations
PXI-based synchronized monitor

Conclusions◆ Several considerations arenecessary to make use of aPulsed positron generator

Robust fast synchronized controls

Separation of Beam Operation
with Virtual Accelerator Concept

virtual accelerators may enablemultiple projects at the sametime.

Every20 ms

Newly developed pulsed magnets◆ Event-based synchronized andF.B

global controls, many pulsed

F.B

devices such as pulsed magnets

PF Injection

ARCprojects◆ Introduction of the concept ofEvent-basedControl Systeme− Gunsingle injector for differente– (2.5GeV, 0.2nC)

Bridge Coils

F.B
e− GunDamping ring

SuperKEKB-LER Injection

ARC

F.B

10 nC
Primary e-e– (3.5GeV, 10nC)

F.B

e+ Targete+ (4GeV, 4nC)

DCFocusing
Magnets Spoiler

SuperKEKB-HER Injection

F.B

e+beamhole

F.B

PulsedCorrector
Magnetse– (7GeV, 5nC)
e− GunARC

PF-AR Injection

F.B

e– (6.5GeV, 5nC)

LAS Accel.
Structure

Targete− GunARC

Solenoid

Pulse-to-pulse modulation

4 nC Injection e-Flux
Concentrator

PulsedFocusing
Magnets

Side viewor fast monitors support such anidea.
◆ Online simulation environment

for each virtual accelerator
would further enrich the concept.