A REAL-TIME OBSERVATION SYSTEM OF ACCELERATOROPERATION USING JAVA
M. Mutoh, M. Nanao and O. Konno
Laboratory of Nuclear Science, Graduate School of Science, Tohoku University
1-2-1 Mikamine, Taihaku-ku, Sendai 982-0826, Japan

Abstract
A stretcher-booster ring (STB) was constructed atTohoku University. Real-time information on the STB
operation is provided through the Internet. Our goal forthis system is for accelerator researchers and engineers tobe able to diagnose any accelerator problems from theiroffices or homes via the Internet. A recently developed
Java language is used for various graphic displays of theoperation records which are saved in the database. The
database which provides real-time information to theInternet is separated from the control database and has
been installed on the www server. This has been done toprotect the control database from illegal access from theInternet and also to help reduce the CPU load in the
database server used for the accelerator control. The
transmission of the data from the control database to the
www database is achieved using a replication function
having the MS-SQL. The control database is defined as apublication-server, and the www database is defined as a
subscription-server. Vacuum pressure in the STB and abeam current of an experimental target point are currently
displayed on our laboratory’s home page using Javaapplets, we will provide other information about the statusof the operation to the Internet soon.

1 INTRODUCTION
The World Wide Web (www) has become rapidly
more popular, because it allows easy access to a wide
variety of information from across the world and because
it is an open system independent of computer platforms.
At the inception of the www, the information flow using
only HTML was a one-way communication from the www
server to the browser. Further development of thecomputer and network technologies made possible twoway communication between the source and destination of
information on the Internet. In particular, the appearanceof Java language made it possible for the www to expand
into the transmission of dynamic information using
animation, video or voice. We propose here that if thesenew Internet or Intranet technologies were applied to an
accelerator control system, it would be possible toconstruct a real-time observation system to provide
constantly updated information on the accelerator’soperation.

The STB [1], constructed at our laboratory in theautumn of 1997, has been operating under test conditions
and will soon begin practical operations for nuclear
experiments. Accelerator engineers and physicists wanted
information on the STB operation to be available on theInternet so that they could monitor the conditions of theaccelerator’s operation and diagnose any accelerator
problems from their offices or homes. We therefore havebeen constructing a real-time observation system, and so
far the conditions of the STB vacuum system and theaccelerated beam current at the experimental target point
have been transmitted graphically and dynamically in Javaapplets on the Internet. We aim to present via Internet allof the information on the accelerator operation that is
ultimately saved into the control database.

2 DATABASE SYSTEM
The structure of the database system in the STB control
is shown in Fig. 1. The STB control system [2][3] consistsof eleven personal computers and a database server
computer , which acts as a control manager in the core ofthe control system [4]. All operation data from theaccelerator devices are collected into a database server
known as a control database. The collected data in thecontrol database is processed and distributed to theoperator consoles or accelerator devices as feedback data.
If the control database can be accessed through theInternet, all information concerning the accelerator
operation can be accessed easily. In order to prevent
illegal access to the control database via the Internet, thedatabase for providing real-time information to theInternet is kept separate from the control database andinstalled on the www server. Separating these databases
helps also reduce the CPU load in the server computerthat is used for STB control. Both the STB control
database and the www database are MS-SQL Server. Thewww server is connected with a 100Base-TX/FX network
for the STB control and through a campus network
extended to the Internet. The transmission of the datafrom the control database to the www database isachieved using a replication function having MS-SQL.
The control database is defined as a publication-server,
and the www database is defined as a subscription-server.
Consequently, accessing the www database is equivalent
to accessing the control database, and furthermore, if thewww database were issued the wrong SQL command andAt present, the following four applets
are offered for the observation of theSTB operation information:(1) statuses of valves and actualpressure measured in vacuum
gauges and ionization pumps in
the STB vacuum system,(2) distribution map of vacuum
pressure in the STB using a bargraph,(3) past record of vacuum pressure in
the STB over one week,(4) past record of the beam current
from the accelerator over 24 hours.
Figure 1: Structure of the database system in the STB control.
A display window for the record ofpast vacuum pressure is shown in Fig. 2.
temporarily destroyed, the accelerator’s operation wouldA device list of ten pressure gauges and twenty-sevennot be affected.
ionization pumps and a color list appear in the window,
At present, the status of the vacuum components andand the observer can select the gauges or the pumps to be
the vacuum pressure values are collected at 2 minute
observed using the mouse on the client computer. Theintervals and the past week’s worth are saved in the www
selected device’s data is sent from the www server to thedatabase. Also, the beam current values collected at 2client computer every two minutes, and past records areminute intervals over the 24 hours are saved in the www displayed with selected color and updated whenever data
database. Past records of these values can be observed
comes in. Moreover, the displayed graphs can be shifted
graphically on web-browser via the Internet [5]. We arein the window using the scroll buttons to view data frompresently preparing other data for presentation on the web,anytime within the last week. Fig. 3 shows the distribution
for example, fluctuations of RF frequency, power level
map of vacuum pressure in the STB. The horizontal axis
and phase, water flows and temperatures in coolingnumbers in the window indicate the ionization pump’ssystem, statuses of the magnet power supplies, wave-form names.
signals and pictures from beam monitors, operation logs,
alarm records and so on. In addition, we will soon extend
4 CONCLUSION
the data range within our main facility, an electron linear
The STB operation information, which has been
accelerator to provide for the internet.
provided through the Internet, has been helpful forengineers and physicists, and the provision of more
3 JAVA APPLET
information on the accelerator operation and nuclear
In order to display the STB operation information
experiment conditions has been enthusiastically requested.
graphically and dynamically on the web-browser, weWe plan to not only extend the information that is offered,elected to use Java applet. Java has the following
but also to develop various Java components to facilitate
excellent features:the design of an effective Java programming environment.
(1) it is executable on computers supporting multiple
platforms such as Windows, Macintosh, and Unix,
REFERENCES(2) it provides easy access to data or application[1] T. Tamae et al., “1.2GeV STRETCHER-BOOSTER RINGprograms on remote computers via the computer
PROJECT AT TOHOKU UNIVERSITY”, The XVI RCNP
network,
OSAKA International Symposium on Multi-GeV High(3) it offers simple program structure and effective
Performance Accelerators and Related Technology, Osaka,
programming development by means of objectJapan 1997
[2] M. Mutoh et al., “A New Approach to Control System fororiented programming,
Medium-Scale Accelerators”, International Conference on(4) it contains useful Graphical User Interface (GUI)
Accelerator and Large Experimental Physics Control
components like buttons, check-boxes, lists, labels,Systems, Chicago 1995
text and so on, making it easy to communicate via[3] M. Mutoh et. al., “The Present Status of the Control System
for a Stretcher-booster Ring at Tohoku University”,mouse.
PCaPAC99
The display programs written in the Java language
are converted to a middle-code called Java applet by [4] M. Mutoh et al., “Improvements in Database System forAccelerator Control”, International Conference on
the Java compiler. Java applets are put into the www
Accelerator and Large Experimental Physics Control
server, transferred to the client computer and executed
Systems, Beijing 1997
[5] URL:http//www.lns.tohoku.ac.jp/operation/operation.html
by the web-browser.

Figure 2: Past record of vacuum pressure in the STB.

Figure 3: Distribution map of vacuum pressure in the STB.