JAERI-Conf 95-021

PB14
CONTROL SYSTEM FOR RCNP CYCLOTRONK. Tamura, K. Hosono, K. Hatanaka, I. Miura, T. Saito, T. Yamazaki, T. Itahashi,
A. Shimizu, K. Nagayama, M. Kibayashi, M. Uraki, H. Tamura

Research Center for Nuclear Physics, Osaka University, Osaka 561, Japan
Abstract
The control system of the AVF-cyclotron is upgraded in the summer, 1995. As the result we canoperate the beam form the ion source to the target by using the unified control system. At thesame time we upgrade the power supplies of AVFcyclotron.
1. Introduction

The control system of the AVF-cyclotron has
been working for more than twenty years. Recently
it becomes difficult to maintain the control system
for the operation. The AVF-cyclotron has important role as the injector of the Ring-cyclotron. Inorder to supply the stable beam and makes the operation of cyclotron more simply, it is necessary tounify the control system of AVF -cyclotron and Ringcyclotron.[!] We shall replace the control system inthe summer, 1995. At the same time, we shall update the power supplies and the RF system of AVFcyclotron. These projects are expected to get higher
quality of the accelerated beam for the high resolution measurements. Furthermore, we have someplans of feedback systems for the beam acceleration.
The unification of the control systems is also important to construct feedback systems for the cascade
accelerators. The summary of this project is as follows.
2. Computer system
Thecontrol system of AVF-cyclotron is connected to the network system of the computercomplex of the Ring-cyclotron facility. (Fig.l) The
Universal Device Controller (UDC) controls the devices and collects the status of devices. [2] There willbe 60 UDCs for the new control system of the AVFcyclotron. The UDCs are grouped according to therole so that the variety of UDC becomes minimum.
A new Group Control Unit (GCU) is devoted tocontrol the devices of the AVF-cyclotron and theion-source. The performance of the main computer(SCU) is in a limit only for the operation of Ringcyclotron. Obviously we expect the present computer is not suitable for the coming operation

ION

AVF

L.----- ---------- ~Fig.l: Computer and network system of control system. The SCU, GCU, UDC and operator console
will be updated. (surrounded by dashed-lines)
after the replacement of the control system. The
main computer will be upgraded from micro VAX
4000/200 to micro VAX 4000/500. We shall makegood use of the past main computer of the RCNP
VMS cluster computing facility.
3. Power supply
The power supplies of AVF-cyclotron facility havebeen operated by setting the reference voltage withthe pulse motor deriving system. This pulse motor
system may be one of reason for difficulty of maintenance and instability of the accelerated beam. We
shall reconstruct and update all of power supplies of
AVF-cyclotron facility. The reference voltage for thepower supply is set by the 16 bit digital-to-analog
convertor and the output current is monitored byusing the 12 bit analog-to-digital convertor.
4. Beam diagnostic system
The pulse motor deriving systems, such as the beamdiagnostic system, are not replaced in this project.
The UDC simulates the preset control sequence ofthe driving circuit. The output from the beam diagnostic system is measured by using updated current-287-JAERI-Conf 95-021

as much as possible from the new console. We adopt
amplifier and transferred to the computer ·controlsystem. The results of beam diagnosis are shown on personal computers for the new console which aresimply connected with the main computer throughthe graphical display as used in the Ring-cyclotron
Ethernet.
facility.
5. Interlock system
The interlock system of AVF-facility has beenvery complicated and it is very important for theradiation protection. While we shall not update theinterlock system in this project avoiding unexpected
error in the interlock system, the new control systemcollects the information of the interlock system andinforms the status of the cyclotron for the operators.
This is a characteristic advantage of the computer
control system.

Reference(1) K.Tamura et al., RCNP Annual Report
1993, pp.190-192.
(2) T.Yamazaki et al., Proc. 13th Int. Conf.
on Cyclotron and Their Applications, Vancouver, C~ada, 1992, pp.t>72-675.

6. Console
There are twin operator consoles for the Ringcyclotron facility. When we unify the control system
of AVF and Ring facility, the devices in the AVF facility can be controlled from the operator console ofthe Ring facility. However we must pedorm extensive operation to tune up the Ring-cyclotron using
both of operator consoles. Therefore the twin operator consoles may not be enough for the future operation of cyclotron. We shall construct new consoleof the control system.(Fig.2) The console of Ringcyclotron is closely connected to the main computerby using special electric circuits. Already these special electric circuits give rise to difficulties of themaintenance of the control system. By this reason
we shall purge these special electric circuits

Fig.2: View of new operator consoles.

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