DESIGN AND STATUS OF THE SUPERKEKB ACCELERATOR CONTROLSYSTEM
M. Iwasaki#, A. Akiyama, K. Furukawa, H. Kaji, T. Naito, T. T. Nakamura, J. Odagiri, S. Sasaki,KEK, Ibaraki, JapanT. Okazaki, N. Yoshifuji, EJIT, Hitachi, Ibaraki, Japan
M. Hirose, K. Iwase, KIS, Ibaraki, JapanT. Aoyama, M. Fujita, T. Nakamura, N. Tanaka, K. Yoshii, Mitsubishi Electric System & Service
Co. Ltd, Japan
Abstract
We have designed and upgraded the accelerator control
system for SuperKEKB, the next generation B-factory
experiment in Japan. The SuperKEKB control system isbased on the features of the KEKB control system, while
additional technologies have been implemented. In thispaper, we describe the design and current status of theaccelerator control system for SuperKEKB.

network topology. The main network switch is located atthe SuerKEKB control room. All network switches,
located at 26 sub control rooms along the SuperKEKB
main ring, the SuperKEKB injector linac (Linac), and AR,
connect to the main switch in the SuperKEKB control
room with optical cables.
In KEKB, the bandwidth of the network switches was
100MbE or 1GbE. For SuperKEKB, the 10GbE network

INTRODUCTION
SuperKEKB is the upgrade of the KEKB asymmetricenergy electron-positron collider for the next generation
B-factory experiment in Japan [1]. It was approved and iscurrently under construction. The designed luminosity isto achieve a 40-times higher luminosity than the world
record by KEKB.
The KEKB control system was based on EPICS(Experimental Physics and Industrial Control System) [2]at the equipment layer and scripting languages at theoperation layer. The SuperKEKB control system
continues to employ those features, while we implement
additional technologies for the successful operation atsuch a high luminosity.
In the accelerator control network system, we introduce
10 gigabit Ethernet (10GbE) for the wider bandwidth datatransfer, and redundant configurations for reliability. The
network security is also enhanced. For the SuperKEKB
construction, the wireless network is installed into thewhole area of the accelerator tunnel.
We have developed the interface modules to control
thousands magnet power supplies, and introduce theEPICS embedded PLC, where EPICS runs on a CPUmodule. In the timing system, the new configuration for
positron beams is required. For SuperKEKB, the faster
response beam abort system has been developed.
This paper describes the design and status of theSuperKEKB accelerator control system.

NETWORK SYSTEM FOR SUPERKEKBWe have upgraded the accelerator control network
system for SuperKEKB [3]. Fig. 1 shows the schematic
view of the SuperKEKB accelerator main ring. The
accelerator control network system employs a star____________________________________________#masako.iwasaki@kek.jp

Figure 1: Schematic view of the SuperKEKB acceleratormain ring. Red star indicates the SuperKEKB controlroom. Blue circles are the sub control rooms, locatedalong the SuperKEKB main ring, Linac and ARswitches will be installed into the all sub-control rooms
along the SuperKEKB main ring and Linac. We haveinstalled the single-mode optical cables to assure the10GbE data transfer. For the redundant structure, subcontrol room switches connect to the main switch with

two lines each, and form the active-standby configuration.
The 10GbE network switches will be installed within thisJFY.

network. We also change the account system, and the only
SuperKEKB collaborators logged into the computers in
the accelerator control network. This summer, wechanged and applied the new network configuration.

VLAN segmentation for SuperKEKB
Since EPICS, which is used as the main software tocontrol the accelerator for KEKB and SuperKEKB, uses
the UDP broadcast to make communication between
Operator Interfaces (OPIs) and Input/Output Controllers(IOCs), there are many UDP broadcast packets in theaccelerator control network.
In SuperKEKB, the number of the controlled devices,which have the Ethernet interface to connect with theIOCs, increases, and these devices also receive the UDP
broadcasts. Several devices cannot properly operate under
the high rate UDP broadcast environment.
To prevent such UDP broadcast effects, we apply theVLAN-based network segmentation to the SuperKEKB
control network. Here IOCs and the accelerator
components with Ethernet interfaces are in the different
VLANs. We have tested the VLAN segmentation, andconfirmed that the device with an Ethernet interface in thedifferent VLAN operates properly.

Installation of the wireless LAN system into theaccelerator
It is important to provide the convenient network
environment for the efficient accelerator construction andmaintenance of it. We install the new wireless network
system based on the Leaky Coaxial (LCX) cable antennas
and collinear antennas into the SuperKEKB acceleratortunnel.
The 16 20D-type 125m-length-LCX antennas, 2000m
length in total, are installed into the 4 arc sections, and 16
collinear antennas are installed into the 4 linear sections
covering 1000m length area.
For SuperKEKB, we have selected the LCX andcollinear antennas which have good radiation hardness ofmore than 1MGy. Fig. 3 shows the installed LCX antenna
into the SuperKEKB arc section. As shown in the figure,
all access points, as well as PoE modems for power
supply in the tunnel are installed within the lead boxes.

Network reconfiguration to connect with theKEK network
For SuperKEKB, we reconfigure the network design asshown in Fig.2, to enhance the reliability and security ofFigure 3: An access point and a 125m length LCX
antenna installed at the SuperKEKB arc section. The
access point is located in a lead box.

Figure 2: New configuration for the SuperKEKB
accelerator control network and the KEK network
connection.
the network. In KEKB, there were many computersconnecting to both KEK and KEKB-accelerator-control
networks. For SuperKEKB, all computers in theaccelerator control network do not connect to the KEK

After the installation, we tested the wireless LANsystem. We obtain the good performance of about
18Mbps effective transmission rate in the whole area of
the SuperKEKB tunnel. In addition to the 32 accesspoints installed in the SuperKEKB main ring, we also
install the access points into AR, Linac, SuperKEKB sub
control rooms, and power equipment rooms at the power
equipment buildings. Total 70 new access points arecontrolled by an access-point controller.

SOFTWARE AND HARDWARE
INTERFACE FOR SUPERKEKBFor KEKB and SuperKEKB, EPICS is used as the main
software to control the accelerator at the equipment layer.

The EPICS framework consists of the Operator Interfaces(OPIs) and the Input/Output Controllers (IOCs). In KEKB,
our system was constructed with the EPICS base version
3.13. For SuperKEKB, we’re going to update to theversion 3.14, however there still remain IOCs which are
based on the EPICS base v3.13. For the operation layer,
several script language of SAD script, python are used.
In KEKB, VME single board computers with VxWorks
are mainly used as IOCs. For SuperKEKB, as well as theVME/VxWorks, the PLC (programmable logic controller)
with a CPU module where Linux is running, and theLinux PC are also used as IOCs. Fig.4 shows the picture

accelerator components, such as Ethernet, GP-IB, serial,
VXI/MXI for BPM, ARCNET for magnet power supply,and CAMAC. For the magnet-power-supply control, we
have developed the interface module [5]. Fig.5 shows thepicture of the prototype PSICM (Power Supply InterfaceController Module) for SuperKEKB. The new PSICM hasfeatures of the faster data transfer rate of 10Mbps or5Mbps (2.5Mbps in KEKB), 32-bit data handling tosupport the 24, 20, or 18-bit resolution DAC (previousPSICM supports 16-bit only), and redundant timingsignal inputs.

Data Archiving System

Figure 4: Picture of the PLC modules for the beamcollimator controller.
of the PLC modules for the beam mask controller. In theCPU module (Yokogawa F3RP61), Linux is running, andwe install EPICS into the CPU module to control the PLC.
For SuperKEKB, the F3RP61 module is used to control
the many devices of, for example, the vacuum system,
LLRF, the automatic calibration subsystem for the largetype-magnet power supply, and beam collimators [4].
There are many kinds of fieldbus in SuperKEKB

Figure 5: Prototype of the PSICM (Power Supply
Interface Controller Module), used for the magnet power
supply control for SuperKEKB.

In KEKB, we have used KBLog as a data archivingsystem. In SuperKEKB, we continue to use the KBLog,
as a primary data archiving system which is the file based
logging system. In addition, as the second option, the newdata archiving system based on the CSS [6] (ControlSystem Studio) Archiver is also used. The CSS isoriginally developed at DESY, and has many generalsoftware components for the device control. CSS-based
Archiver is one of the CSS tools, which collects datausing the EPICS Channel Access protocol, and stores thedata to the backend relational database system. Here we
use PostgreSQL for the database system. The databasecan be directly accessed with CSS, and the CSS installedusers PCs can be remotely access to the database for thereal-time, historical, or trend data monitoring.
Currently, the CSS Archiver with the PotgreSQL
backend database is running on our system. It collects thevacuum system data and the cryogenic data for the final
focusing superconducting magnet system, and works
without problem so far.
Since CSS provides many tools, we also consider thealarm system with CSS for SuperKEKB.

TIMING SYSTEM FOR SUPERKEKBIn SuperKEKB, we construct the positron Damping
Ring (DR) to produce the lower emittance beams. The
KEKB timing system is based on a frequency
divider/multiply and a digital delay technique. Since theKEKB ring RF (508.887MHz) is not a divisor of the
Linac RF (2856 MHz), both of the KEKB ring and the
Linac frequencies are locked with a common divisor
frequency (10.385 MHz = 96ns cycle), which determines
the injection timing. For the SuperKEKB positron
injection, the injection timing of 96ns cycle for KEKB
becomes 11.34 ms, because of the properties of DR, if we
use the similar configuration as KEKB [7].
Instead of this, we have developed the new timing
system, which generates the injection timing signals.
Fig.6 shows the layout of the event timing system locatedat the Linac main trigger station for the SuperKEKB
positron injection. The system consists with two layers ofevent generators (EVGs). As EVG detects the externaltrigger, EVG generates and sends the timing signal to theevent receivers (EVRs). The trigger for the upper layer
EVG (global EVG) is a coincidence between 50Hz and11.34 ms cycle, which corresponds to a few second cycle.

the abort kicker. In KEKB, these modules are connectedwith wires, and low pass filters which caused time delayof ~100µs were necessary for the noise reduction. ForSuperKEKB, we have adopted the E/O conversion,replaced the wires with the optical fibers to transfer thesignal, and removed the low pass filters from the system.
The total abort system response time is improved to 20 µs.

RENOVATION OF THE CONTROL ROOM

Figure 6: Layout of the event timing system at the Linac
main trigger station for SuperKEKB positron injections.
The global EVG sends the 50Hz timing signal for EVR.
The EVR outputs 50Hz trigger signals to the lower layer
EVGs (local EVGs). The local EVG for the Linac below
the DR, generates the timing signals, in taking account forthe proper positron injections. Currently, several
feasibility studies are carried out.

SUPERKEKB BEAM ABORT SYSTEM
We have developed the faster response beam abortsystem for SuperKEKB. Fig.7 shows the layout of theabort system for SuperKEKB.
There are over 130 points which monitor the beam
status and issue the abort signal. The abort signal is E/Oconverted, and received by the VME abort modules
located at the local control rooms. 20 local abort modules
are connected to the abort module in the SuperKEKB
control room, which gathers the local abort modulesignals, takes OR of them, and issues the trigger signal toFigure 7: Layout of the abort system for SuperKEKB.

We are currently renovating the SuperKEKB control
room and the computing room. We removed old panelboard cabinets and server racks from the computing room.
Total 3t weight signal and power cables, which were used
at TRISTAN and KEKB, are removed from computing
and control rooms. New server racks, located at thecomputing room have the plugs with a power monitor.
We install modules for power supply into the server racks.
The new server racks and power supply modules are
installed by this November. We have also design theconsoles for the SuperKEKB control room.

SUMMARY
We have improved the accelerator control system forSuperKEKB operations under the 40-times higher
luminosity than the world record achieved by KEKB.
Based on the KEKB accelerator control system, we have
implemented the new features of the redundant and wider
band width network, the improved control software tools
and interfaces, the new data archiving system, the newtiming system, and the faster response abort system. We
have also renovated the main control room and have been
preparing for the first SuperKEKB operation in 2015.

REFERENCES[1] SuperKEKB Task Force, Letter of Intent for KEK
Super B Factory, KEK-REPROT-2004-4, Jun. 2004.
Belle II Collaboration, KEK-REPORT-2010-1, Nov.
2010.
[2] http://www.aps.anl.gov/epics/[3] M. Iwasaki et al., “Design and Status of theSuperKEKB Accelerator Control Network System”,
THPPC009, these proceedings.
[4] J. Odagiri et al., “Integration of PLC with EPICS
IOCforSuperKEKB
ControlSystem”,
MOCOBAB02, these proceedings.
[5] T. T. Nakamura et al., “Upgrade of the Power Supply
Interface Controller Module for SuperKEKB”,
TUPPC089, these proceedings.
[6] http://www.aps.anl.gov/epics/eclipse/[7] H. Kaji et al., “Upgrade of Event Timing System at
SuperKEKB”, THCOCA04, these proceedings.