CONTROL SYSTEM FOR AN INDUSTRIAL ACCELERATORTECHNOLOGICAL COMPLEX.
V.N.Boriskin*, N.I.Aizatsky, YU.I.Akchurin, V.A.Gurin,N.V.Demidov, A.N.Dovbnya, V.A.Kushnir, V.V.Mitrochenko,
A.N.Savchenko, YU.D.Tur, V.L.Uvarov.
National Science Center, Kharkov Institute of Physics&Technology (KFTI), Ukraine
This paper deals with the control and protection system for an electron linac for industrial purposes (KYT). The KYT
is a powerful source of accelerated electron beam and is designed to be used for radiation processes includingsterilization of medical supplies. KYT was designed and constructed in KFTI. The pilot KYT has been operating
since September 1993. This linac produces a 8-10 MeV electron beam with a power of up to 10 kW. The
commercial production of KYT was started in 1994. A description of the system ispresented.

HARDWARE AND TECHNICAL SUPPORTThe linac includes the high-voltage generator, the electron source, the accelerating system, a klystron with
its high-voltage modulator and a scanning and electron beam extraction device. The control system provides the beam
current and energy monitoring, the control of system parameters and fault diagnostics of the linac units, theprotection for the accelerator system against damage by the beam, interlock protection for the modulator and klystron
amplifier against incorrect operation, regulation of the currents in the magnet power supplies, regulation of the phaseand power of the RF system, control of the irradiation dose at the target and monitoring of target transportation
system.
The layout of the system is shown in figure 1. The hardware consists of a personal computer equipped withanalog-to-digital converters (ADC). This is connected by a local area network to the units shown below, which aresituated about 40 m from the PC. There is a synchronization unit (SU) and three microprocessor controlled units:
one for the klystron amplifier modulator (KAM), one for the technical services (TS), and one for the target
transportation system (TT). The control system of the experimental model of KYT was made using the CAMAC
standard [1]. However, this was too complicated for industrial usage, so the new version of the system will not use
CAMAC.

PCADC

TTHS

KAM

micro

micro

micro

SULINAC
Fig. 1. Schematic of the control system.

The ADC units receive signals from analog pulse detectors. They have two switched channels with 100 ns
period and two integrating channels. The SU assigns time-dependent programs to the pulse generation system, thecontrol system subunits and the measuring equipment. The linac operation frequency can be selected within the rangeof 25 - 300 Hz, while in emergency situations or during a bean commissioning run it can be lowered to 6.25 Hz.
Switching on the SU automatically brings back the operation regime which was in use when the SU was previously
turned off.
The KAM unit monitors the operation of the klystron modulator, ensuring the interlocking of the HV-supply
and beam switch-off, when the accelerator equipment enters into a hazardous state of operation, or when its operation
becomes dangerous for service personnel. This unit controls about 60 digital and analog signals.
The HS unit controls the operation of two cooling and three precise temperature controlled water circulating
systems, monitors the temperatures in the accelerator main components and the water flows in the cooling systems,
using thermocouples and sensors. The TT subunit controls the magnetic elements of the accelerator and the targettransportation system.

SOFTWARE AND PROGRAMMING
The program package CSL (Control System Linac 1.2), written in C, provides for the CS operation in threestages:- linac switch-on and -off,- parameter variation and control,- automatic control, identification of any deviations from the assigned operation parameters and monitoringof the irradiation process.
Information on the system operation and the electron beam parameters is fed to monitors on the local control
panels at each of the subunits TS, KAM, SU, TT, and to the color graphics three-screen display at the main control
console. Control of the accelerator operation can be carried out either by the operator at the main console PC
keyboard, or from the local control panels. For each of the 16 main accelerator systems there is a corresponding
overlay module in the CSL, called by the basic monitoring software. These program modules allow the operator tomonitor single or multiple systems parameters, to give commands, to save and view archive files, to control theradiation dose, to control the transport system for the articles being irradiated, etc. Parameters of several systems canbe monitored simultaneously, but only sone ystem can be regulated at a time.

CURRENT STATUS AND PROSPECTS
At the present time different versions of the system described above are working at two accelerator complexes.
Two new KYT-2 accelerators which are now being manufactured will be supplied with similar systems.

REFERENCE
1. V.N.Boriskin et al. Control system for a linear resonance accelerator of intense electron beams / Nucl.
Instr. and Meth. in Phys. Res A 352 (1994) 61-62.