JACoW is a publisher in Geneva, Switzerland that publishes the proceedings of accelerator conferences held around the world by an international collaboration of editors.
TY - CONF AU - Aoyagi, T. AU - Matsuzaki, Y. AU - Nobusaka, H. AU - Takahashi, M. AU - Terakado, T. AU - Yagyu, J. ED - Pak, Cheol-on ED - Kurokawa, Shin-ichi ED - Katoh, Tadahiko ED - Furukawa, Kazuro ED - Schaa, Volker RW TI - Very Fast Feedback Control of Coil-Current in JT-60 Tokamak J2 - Proc. of ICALEPCS1991, Tsukuba, Japan, 11-15 November 1991 CY - Tsukuba, Japan T2 - International Conference on Accelerator and Large Experimental Physics Control Systems T3 - 3 LA - english AB - A direct digital control (DDC) system is adopted for controlling thyristor converters of power supplies in the JT-60 tokamak built in 1984. Microcomputers of the DDC were 5 MHz i8086 microprocessor and programs were written by assembler language and the processing time was under l ms. They were, however, too old in hardware and too complicated in software. New DDC system has been made in the JT-60 Upgrade (JT-60U) to control the power supplies more quickly under 0.25 and 0.5 ms of the processing time and also to write the programs used by high-level language. The new system consists of a host computer and five microcomputers with microprocessor on VMEbus system. The host computer AS3260 performs on-line processing such as setting the DDC under the discharge conditions and so on. Functions of the microcomputers with a 32-bit, 20 MHz microprocessor MC68030, whose OS are VxWorks and programs are written by C language, are real-time processing such as taking in instructions from a ZENKEI computer and in feedback control of currents and voltages of coils every 0.25 and 0.5 ms. The system is now operating very smoothly. PB - JACoW Publishing CP - Geneva, Switzerland SP - 442 EP - 445 KW - controls KW - power-supply KW - real-time KW - plasma KW - software DA - 1992/12 PY - 1992 SN - 2226-0358 SN - 978-3-95450-254-7 DO - doi:10.18429/JACoW-ICALEPCS1991-S12FC09 UR - https://jacow.org/icalepcs1991/papers/s12fc09.pdf ER -