IPP to develop plasma control system for the ITER test reactor

Cooperation agreement concluded / Software for the ITER international fusion test reactor

The complex software by means of which the ITER international fusion reactor is to be operated and the plasma experiments are to be controlled in real time is to be developed by Max Planck Institute for Plasma Physics (IPP) at Garching bei München in conjunction with the ITER organisation at Cadarache, France. The software will first be tested on Garching’s ASDEX Upgrade fusion device, which will then be completely switched over to the new control system. The cooperation, scheduled to last about six years, was recently ratified.

The objective of fusion research is to develop a climatically and environmentally safe power plant that derives energy from fusion of atomic nuclei like the sun and stars. This is to be accomplished by confining the fuel, a hydrogen plasma, in a magnetic field cage without wall contact and heating it to ignition temperatures exceeding 100 million degrees. The ITER test device, now being built as an international venture, is to demonstrate for the first time that an energy-yielding fusion fire is possible. “The ITER control system will therefore have to be more complex than all previous systems”, explains Dr. Axel Winter, who is responsible in the ITER team for the control software.

The data measured by about a hundred diagnostics monitoring the ITER plasma will be recorded by the control system, evaluated and used in real time to regulate the device's systems, e.g. the magnet coils, plasma heating systems, fuel feed or the pumps. This will tailor the scenario of plasma experiments lasting 5 up to 50 minutes to the scientists’ specifications. “This calls for a smart system”, states Axel Winter, “that can quickly react to the fast plasma processes. It must also be robust and so flexible that it can be further developed for many years of operation and adapted to changing conditions”.

The agreed cooperation will proceed in three phases: The complex programme structure will first be designed by the ITER-IPP collaboration, the software will then be written by a private company, and then tested on IPP’s ASDEX Upgrade device. Here the physicists can enlist a great deal of relevant experience. Instead of the previous standard analogue systems, Upgrade’s predecessor, ASDEX, put the world’s first completely digital plasma control system into operation in 1988. On ASDEX Upgrade the first modular framework-based control system has been in operation since 2000. The numerous diagnostics and systems of the device are coordinated by way of this framework in their diverse input and output processes. It makes the data available, regulates intercommunication among the various units and controls the plasma discharge in keeping with the scientists’ specifications. An example of these complex control tasks is featured in Press Release 12/2012.

A framework structure is also desired for the ITER control system. Testing it on ASDEX Upgrade will first involve applying it in parallel to the existing system for controlling a single diagnostic and testing it in daily operation for about two years. Modified in accordance with the experience gained, the new system will finally be completely adopted and routinely control the discharges in ASDEX Upgrade. “As the device will then use exactly the same software as ITER, we are expecting major synergies”, states Dr. Gerhard Raupp, the person responsible at IPP for the project. “This affords IPP the unique possibility of preparing control tasks for ITER on ASDEX Upgrade. Future ITER operators can then be taught and trained on ASDEX Upgrade.”

Isabella Milch