Mass data acquisition systems in JT-60 data processing system

In the data processing system for the JT-60 tokamak, a unique mass data acq uisition system with fast sampling, a transient mass data storage system (T MDS), has been used since 1988. It is composed of a minicomputer and 61 cha nnels of 4/6 MB memory modules with a sampling rate up to 200 kHz and about 300 MB of data are transferred to a main computer by using a special LAN d eveloped by Fujitsu Ltd. TMDS can handle a large amount of data, but cannot be enlarged in its capability, such as CPU power or the number of channels . To solve the problems of TMDS, a new fast VME data acquisition system (FD S), has been developed. It can acquire 6 MB of data per channel with a samp ling rate of 200 kHz or 1 MHz and consists of a workstation with VMEbus mem ory modules. Up to now there are three FDSs with 24 channels. The minicompu ter of TMDS has been replaced with a new system based on the technology of FDS. To cope with mass data transfer to a data server, they are connected w ith a gigabit ethernet switch. (C) 2001 American Institute of Physics.