Computing Seminar

SST-1 Data Acquisition and Control System

H. D. Pujara, Institute for Plasma Research, Ghandinagar, India

Abstract

SST-1 is a steady state Tokamak device which is designed for fundamental study of plasma physics. SST-1, being a steady state device, will require real time control and data handling, analysis and displaying capabilities. The continuous nature of operation has a significant effect on instrumentation and control; the internal architecture of digitiser and controller also plays a major role on performance.

Since shot duration is 1000 seconds, to limit the volume of data generated different strategies have been adopted for slow and fast diagnostics. The low frequency diagnostics demanding continuous acquisition will be based on PXI system directly streaming to hard disk and network for online storage and viewing. High frequency diagnostic data will be acquired on known events and will be stored in different segments of memory. Special purpose CAMAC modules have been developed in house.

SST control system will be based on a distributed control system. For efficient management of system components, they have been divided into three groups: Machine Control System, Discharge Control System and Diagnostics Supervisory Control. Machine control system will configure and operate various technical subsystems with a hierarchical control structure.

The discharge control system will be a real time control system based on VME and RTOS which will take decisions regarding operational phases and will control plasma parameters. Discharge control will be active during discharge and discharge related subsystems would be under direct control of discharge control supervisor. The system will be using reflective memory for real time digital data transfers across the various subsystems.

About the speaker: H.D. Pujara has been with the Institute for Plasma Research for almost 25 years. He graduated in Electronics and Communication. The Institute is engaged in study of fundamental research in the field of magnetically confined hot plasmas. Mr Pujara has been working on data acquisition systems and plasma diagnostics. He is currently leading a group developing data acquisition systems for the SST-1 (Super conductor based Steady State Tokamak).