Computer system for the beam line data processing at JT-60 prototype neutral beam injector

The present report describes the hard and soft wares of the data acquisition computer system for the prototype neutral injector unit for JT-60. In order to operate the unit, more than hundreds of signals of the beam line components have to be measured. These are mainly differential thermometers for the coolant waters and thermocouples for the beam dump components but not include those for the cryo system. Since the unit operates in a series of pulses, the measurement should be conducted very quickly in order to ensure the simultaneity of large number of the measured data. The present system actualize fast data acquisition using a small computer of 128 kB and measuring instruments connected through the bus. The system is connected to the JAERI computer center since the data capacity is fairly large to completely process them by the small computer. Therefore the measured data can be transferred to the computer center to calculate there, and the results can be received. After the system was completed the computer quickly print out the power flow data, which needed much work to calculate with hands. This system was very useful. It enhanced the experiments at the unit and reduced the labor. It enables us to early demonstrate the rated operation of the unit and to accurately estimate such operation data of the JT-60 NBI as the injection power. (author)