Implications for ITER CODAC from DIII-D experience

The DIII-D digital plasma control system (D3PCS) has been in use since 1993 controlling DIII-D plasmas. Control research and D3PCS development at DIII-D has revealed aspects of advanced tokamak control which can help inform the ITER design. The D3PCS has also been adapted for use at several fusion devices worldwide, which has allowed the DIII-D team to obtain a significant understanding of common requirements for plasma control on multiple fusion devices, along with substantial experience in the alternative computing, data acquisition, and networking technologies presently available. We describe some of what has been learned and highlight the relevance of these lessons for ITER Control, Data Access and Communication (CODAC). Several capabilities of the D3PCS are described in the context of ITER requirements. This description touches on multiple subsystems described in the CODAC conceptual design. We also discuss features of D3PCS architecture that are appropriate for today's experimental devices but may not be appropriate for ITER, which requires a much more comprehensive system for ensuring device safety. Even for these applications, the knowledge gained in implementing methods to aid in ensuring device safety on present devices provides useful guidance for an eventual ITER solution.