Software Applications for SPring-8 Accelerator Operations
M. Takao
SPring-8, Mikazuki, Sayo-gun, Hyogo 679-5198, JapanAbstract
Various software applications have been developed forSPring-8 accelerator operations. The effectiveness of thesesoftware tools in the operation of SPring-8 accelerator
complex is reported.

1 INTRODUCTION
The SPring-8 (Super Photon Ring 8-GeV) is a dedicatedsynchrotron radiation facility with an 8-GeV third generation light source storage ring (SR), which has been in operation since 1997. At present, 44 beamlines have been
constructed and in use, 25 of which are for insertion device (ID) and the others for synchrotron radiation by bending magnet. The injector consists of a 1-GeV linac and 8GeV booster synchrotron. The linac is shared with another
1.5-GeV synchrotron radiation storage ring, NewSUBARU(NS), whose injection energy is 1-GeV.
In 2002, scheduled user beam time was 4148 hours andbeam availability was 95.4 %. Beam availability for users
is one of the most important performance parameters of theSPring-8 storage ring operation. To make beam availability as high as possible, we continuously improve both hardware and software operation tools. In this paper we reporthigher level software applications to smoothly operate thecomplicated accelerator complex.

2FRAMEWORK OF SPRING-8
CONTROL SYSTEMThe SPring-8 accelerator complex from linac to beamlines, including the NS storage ring, is controlled in termsof the unified software framework [1, 2, 3]. The SPring8 control system consists of engineering work stations,
VMEbus systems and an optical fiber network system [1].
The remote procedure call is used for the communication
between machine control applications over the network.
The operation history and the equipment parameters are
stored on a database by relational database management
system, Sybase.
The SPring-8 control system heavily depends on thedatabase system [4]. All operation parameters of equipments are stored on the database, and logged data are collected periodically and stored. Logged data are handled inuniform way, so we can easily access them with the sameprocedure. Functions accessing the data are prepared by
the control group, and hence user applications can easily
manage the logged data.
takao@spring8.or.jp

Since the SPring-8 control system is developed under thebasic concept of transparent, a non-expert programmer caneasily build higher level integrated applications for accelerator operations. The higher level application can control an equipment by sending a character command message to lower level control software. The command is acharacter string as the English like syntax, for instance,“put/sr mag ps b/1234.5A”. Furthermore the accessibility
to database also assists in-house staff to develop software
applications for accelerator operations.

3 HIGHER LEVEL OPERATIONSOFTWARE APPLICATIONSCorresponding to the complicated accelerator structure,
there are many operation modes, i.e. linac only, booster
synchrotron injection, SR injection, NS injection, and soon. Both SPring-8 SR and NS have been in operation, we
should daily change operation mode. The switching process of operation mode takes a few tens minutes, and hence
in some case a mis-operation results in no little time loss.
We then developed operation softwares so as to prevent
mis-operations.
Higher level operation software applications for eachcomponent of accelerator complex consist of a control
panel and a status monitoring panel for beam operation.
The task of the control panel is to execute a sequence of
operation process, and that of the monitoring panel is tocheck the ready status of machine for beam injection. The
latter panel permits to turn on beam switch after the condition for beam injection is fulfilled.
Figure 1 is an example of the control panel which is the
top panel for linac control. There are similar control panels
for SPring-8 SR, booster synchrotron, and NS. Main func-

Figure 1: Linac control panel.
tions of linac control panel is as follows.
Setting operation parameters to all equipments oflinac.
Saving operation parameters of equipments ondatabase.
Switching beam route through linac.
Turning on (off) high voltage of electron gun.
For example, in the switching procedure to NS injection
the following procedures are executed sequentially:
1. Changing the mode of the switching magnet to NSinjection.
2. Changing the timing source of linac to NS.

Figure 3: Half part of beamline ready status panel.

3. Setting the gun pulser to 1 ns width.
4. Notifying an operator of changing the operation modeto NS injection.
5. Degaussing the switching magnet.
6. Opening the beam shutter at the beam transport line toNS.
7. Setting operation parameters to equipments of linac.
For the sake of radiation safety, in NS injection mode thepulse width of gun should be 1 nsec and the timing signal
has to come from NS. Similarly, the beam shutter opening
and the excitation of the switching magnet are permitted
only in NS injection mode. If one makes a mistake in beamroute switching procedure, radiation safety interlock acts
on. Top panel of linac control automatically executes theabove switching sequence.
At the Spring-8 SR the status monitoring panel for beam
operation checks ready condition for beam injection, thatis shown in Fig. 2. Each row in the panel corresponds tolabeled equipment groups. When an equipment group becomes ready for beam injection, the button color of the row
becomes blue. After all rows turn blue, the inhibition ofbeam switch is released.

3 is the half part of the sub-panel for beamline ready status monitoring panel. At present, during beam injection ofSPring-8 SR, the main beam shutters for beamlines should
be closed and the ID gaps also have to be fully opened. The
beamline ready status monitoring sub-panel checks theseconditions for beam injection.

4 BEAM LOSS ANALYSIS SOFTWARETOOL
For the purpose of minimizing downtime of user beam,
it is urgently needed to recover the machine from faults.
The SPring-8 SR has two kinds of interlock systems: one
provides radiation safety protection, and the other protects
the ring components from damage by synchrotron radiation. We have developed a software tool to judge the originof beam loss among many faults appearing at the time ofbeam loss, which is shown in Fig. 4.

Figure 2: SPring-8 storage ring ready status panel for beam
injection.
Figure 4: Beam loss analysis panel.
Detailed information on an equipment group can be obtained by the sub-panel opened by clicking the row. Figure

There are provided the beam interlock by beam position

monitors (BPM) placed specially for ID beamline, which
protects beamline components from the damage of intense
synchrotron radiation from ID when electron beam orbit
excursion occurs. If a beam interlock acts on, the stored
beam is aborted by switching off RF power. At the time
beam loss occurred, hence the BPM beam interlock always
issues beam abort request. The beam interlock module(BIM), that forwards the abort requests to RF system, detects which signal comes first. However, the BIM is notaware of beam loss by interlock signals not going through
BIM, such as faults of RF system itself or radiation safety
interlock signal directly going to RF system. Low level
controllers of RF system observe whether RF switch isturned off by an external signal or not. Gathering informations on beam interlock, beam loss analysis panel decides the origin of beam loss. In the case displayed in Fig.
4, the failure of the fast closing shutter at ID beamline 29(BL29IN) causes the beam loss.

frequent beam injection to NS is in progress. NS injection
charge limit panel summarize operation statistics for one
shift, whose printing out is given in Fig. 6. For one shift, thestart and end times of NS injection mode, the beam switch
on time, the total number of the injected pulses, the total,
average and maximum injected charge are all recorded.

5 SOFTWARE LIMITS FOR BEAMINJECTIONS
The maximum stored current of the SPring-8 storage
ring in user beam is restricted to 100 mA by radiation
safety. This limit is secured by the hardwired interlock ofbeam current monitor. We use a software limit to stop beam
injection just before the stored current interlock, which results in loss of stored beam, works on.
The integrated injection charge to NS for one shift isalso severely restricted by the radiation safety and hence
there is provided a hardwired interlock for the beam injection to NS. For the sake of operation convenience, we prepare a software tool limiting the integrated injection charge,
whose display is shown in Figure 5.

Figure 6: Operation statistics for NewSUBARU beam injection.

6CONCLUSIONSThe software applications described here are little partof operation tools developed at Spring-8. Due to high flexisibility and extendability of the SPring-8 control systems,
many software applications for accelerator operations aredeveloped by in-house staff. These integrated softwaretools contributes to stable operation of SPring-8 accelerator
complex with high beam availability for users.
It is planed to put the top-up operation to user beam innear future of SPring-8 SR. It is necessary for top-up operation to control SPring-8 accelerator complex with more
tight connection between injector and SR, and hence themore integrated software tools will be needed. The unifiedcontrol system of the SPring-8 accelerator complex makes
possible to develop such an integrated software applications for the operation.
I would like to thank all members of linac group, ringaccelerator group, control group and opertion group.

7

REFERENCES[1] R. Tanaka, et al., in Proc. of Int. Conf. on Accelerator andLarge Experimental Physics, Chicago, 1995; R. Tanaka, etal., in Proc. of Int. Conf. on Accelerator and Large Experimental Physics, Beijing, 1997;[2] N. Hosoda, et al., in Proc. of Int. Conf. on Accelerator andLarge Experimental Physics, Trieste, 1999;

Figure 5: NewSUBARU injection charge limit panel.

[3] T. Masuda, et al., in Proc. of Int. Conf. on Accelerator andLarge Experimental Physics, Silicon Valley, 2001;

Recording the statistics of the beam injection is anotherimportant task of NS injection charge limit panel, since the[4] A. Yamashita, et al., in Proc. of Int. Conf. on Accelerator andLarge Experimental Physics, Trieste, 1999;