Human Computer Interface for the Computerised Control ofElectron-Cyclotron Resonance Ion Source (ECRIS) at Calcutta
Tapas Samanta, C. D. Datta and D. Sarkar
Variable Energy Cyclotron Centre, 1/AF, Bidhan Nagar
Calcutta - 700064, India
Abstract
Variable Energy Cyclotron Centre (VECC) at Calcutta hasdeveloped a compact room temperature Electron Cyclotron
Resonance Ion Source (ECRIS) for various heavy ion beams.
A PC-based control system for the ECR Ion Source is underdevelopment. A user-friendly Human Computer Interface(HCI) is a vital requirement of the control system of any
modern and sophisticated experimental physics setup. Thispaper describes the HCI of the control system of the ECRIon Source at Calcutta.
1 Introduction
Electron-Cyclotron Resonance Ion Source (ECRIS) becomes the most frequently used heavy-ion source for cyclotrons. To facilitate atomic and nuclear physics researchin Variable Energy Cyclotron Centre (VECC), Calcutta, acompact room temperature ECR type ion source has been
indegeneously developed for production of varities of heavy
ion beams viz. N5+ , O7+ , Ne7+ etc. The details of thisECRIS are found in [1]. A PC-based control system for theECR Ion Source is under development. This paper describes
the Human-Computer Interface (HCI) of the control systemof the ECRIS.
2 Development
A man-machine interface is an essential component of thecontrol system of any modern day sophisticated experimental physics setup. An ECR of this kind consists of not lessthan 12 numbers of pumps, 11 numbers of valves, 28 numbers of highly stable power supplies of various specifications, 8 numbers of gauges and others. Some of the equipment controls (e.g. pumps and valves) are on-off, some areof continuous in nature (e.g. power supplies) and so on.
The starting form displays the overall system (block diagram) of ECRIS at a glance (figure 1). Detailed mimic ofeach of the subsystems with all necessary process parameters
are displayed for monitor and control purposes, at a click ofa mouse button. The current status of each of the subsystems
are displayed as a scrolling text menu and the visual effect isalso provided by changing colour and other attributes.
The Operation sequence starts at a mouse-click at P11 orP12. After starting the diffusion pumping sub-systems, thesystem waits for a few minutes to get the vacuum level of0.01 Tor and then the Turbo pumpimg systems are switchedon. Again the system waits for reaching the ultra high vac-uum. Then it gives a ready signal to the operator audiovisually. The operator starts selecting the current profile andthe specific Ion by clicking over any of the eight solinoid
coils. On completion the system starts up automatically andtunes the Glazers (G11,G12) and the analysing magnet (M1)with the help of the Faraday’s Cup (FC21) as shown in (figure 2). Once the particular beam is available at FC21, thesystem gives ready signal to the operator to proceed. Thenthe Beam Guiding (BG) section becomes active and the operator takes up to switch on the BG section step by step.
The operator can choose from a varities of heavy ion
beams viz. N5+ , O7+ , Ne7+ as a recipe of earlier operations completed with necessary user satisfaction. The recipe
may be modified to suit the special requirement if necessary.
On successful operation, the same can be stored as a newrecipe for use in future. Optional pumping sequence may beinitiated to incorporate breakdown maintenance.
The interlocking parameters of various subsystems havebeen implemented. An auto-start and auto-stop mode of operation have been kept for automatic start up and shut downof the overall system. Operator override on “auto” with all
safety interlocks valid, is incorporated for special override
operation in auto mode.
Special security arrangements have been employed in thesystem to prevent unauthorized entry of operators into thecontrol system. A super-user with all the access rights, isthere to create and restrict the user access and permission. A
simulation mode has been provided for training of the operator and other personnel.
An on-line alarming system has been incorporated to alert
the operator much earlier than a possible breakdown. It will
also store an alarm listing of all the incoming alarms attended, or unattended with acknowledgment time. A graphic
window for monitoring and logging on-line process parameters of operator’s choice, has been provided to track the critical parameters visually. All the details of the parameters
are stored in the disk in case of any abnormal situations forpossible post-analysis.
The database of the subsystem parameters for a particular ion beam energy and other details on the equipment areunder preparation with FOXPRO as local RDBMS and ORACLE for centralised information. A periodic log of parameters will be maintained to provide a snapshot of parametervalues.
The Human Computer Interface has been developed
through Visual Basic version 3.0 on Pentium PC @100 MHz
hardware platform.

Figure 1: Initial stage of simulated operation with the diffusion pumping system and turbo pumping system on.

Figure 2: Simulated operation of beam analysis and tuning.3 Future development
Critical Control Parameter’s PID algorithms are being developed under C++. Tuning algorithm will be developed
using Fuzzy Logic. Interface between the C++ and Visual
Basic has been test developed and to be implemented in detail object level to minimize the code size in Visual Basic.
Dynamic Data exchange feature is used as the medium between the two. Server/Client DDE model with little accessrestriction is tested. Further access restriction is to be implemented. An online context-based help is under development
to guide the operator to make faster decision in case an emergency. Beam analysis & filtering is to be developed to automatically scale the magnetic current and to identify the peaks
for operator selection on a mouse click. Post-Operation analysis and report generation will soon be implemented.
4 Concluding remarks
Visual Basic is one of the Rapid Application Development
Tools available for the developemnt of Human Computer Interface for the Control System Applications. Visual C++,Power Builder etc. are also available. We had experience on
Visual Basic for such applications and this is one of the ma-jor reasons to stick to Visual Basic for such development.
We find Visual Basic as an easier tool for such development
compared to Visual C++. The man-machine interface formonitor and control of power supplies (Danphysik make)has already been developed [2], which will be integrated to
the Control Console of ECRIS. The Interface software withthe equipment level components is being developed in C++.
Acknowledgements
The authors gratefully acknowledge the various technicaldiscussions with A. Roy, T. K. Bhattacharjee, S. K. Pal, T. K.
Das, D. K. Bose and G. S. Taki. The authors also acknowledge with thanks Bikash Sinha, R. K. Bhandari and S.K. De
for their constant encouragement throughout this work.
References[1][2]

Bose D. K. et al. (1995), Proc. 12th International Workshop on ECR ion sources, RIKEN, Japan, p 237.
Datta C. D., S. K. De and D. Sarkar (1997), ”ManMachine Interface for Power Supply Control for ECR
Ion Source”, ICALEPCS’97, Beijing.