Continuous and real-time data acquisition system for superconducting tokamaks HT-7 and TRIAM-1M

Conventional data acquisition systems cannot deal with data acquisition for a long-time discharge of a nuclear fusion reactor. Thus, continuous data acquisition with a real-time data presentation during discharge must be developed. Two data acquisition systems, which include alternating CAMAC data acquisition and long-time PCI data acquisition, are designed for the long-time operation of HT-7 tokamak. Since an effective alternating mode is adopted, the alternating CAMAC data acquisition can accurately and continuously acquire data at a rate of 10 kHz. The acquired data is immediately transmitted to a data server and real-time results can be presented during the plasma discharge. As for the long-time PCI data acquisition, a special kind of PCI A/D card, which has a hard disk on board, is designed to collect data at a max speed of 200 kHz. Thus, the total sampling duration is only related to the capacity of the hard disk on board. These two types of data acquisitions were applied to HT-7 tokamak and a 250 s discharge was acquired. These data acquisition systems were also successfully demonstrated on a 2500 s plasma discharge on TRIAM-1M. This paper describes the two data acquisitions in detail.