Introducing strong radiative impurities into divertor plasmas has been considered as an important way to mitigate the peak heat load at the divertor target plate for ITER, and will be employed in EAST for high power long pulse operations. To this end, radiative divertor experiments were explored under both low (L) and high (H)-mode confinement regimes, for the first time in EAST, with the injection of argon and its mixture (25% Ar in D 2 ). The Ar injection greatly reduced particle and heat fluxes to the divertor in L-mode discharges, achieving nearly complete detached divertor plasma regimes for both single null (SN) and double null (DN) configurations, without increasing the core impurity content. In particular, the peak heat flux was reduced by a factor of ～6, significantly reducing the intrinsic in-out divertor asymmetry for DN, as seen by both the new infra-red camera and the Langmuir probes at the divertor target. Promising results have also been obtained in the H-modes with argon seeding, demonstrating a significant increase in the frequency and decrease in the amplitude of the edge localized modes (ELMs), thus reducing both particle and heat loads caused by the ELMs. This will be further explored in the next experimental campaign with increasing heating power for long pulse operations.
The distant downstream proportional integral(PI) feedback control was applied to the W-M lateral canal of the Maricopa Stanfield Irrigation and Drainage District located in central Arizona,U.S.A.Proper configuration of those controls for the ca-nal can be challenging.Towards this end,an integrated approach to the design of an automatic control system for the canal was proposed.This approach presented herein is not only a systematical review of previous work,but also represents a further ad-vance of the previous simulation study by Tsinghua University(Shang et al,2011) on relating the canal control algorithm to local PI controls for the real canal.To evaluate the control system potential,performance of the control algorithm that was ob-tained through implanting predicative module into linear quadratic regulator(LQR) was analyzed with singular value bode.Additional "manufactured" tests were conducted to compare with the control system that is currently in use.The results indi-cated that the developed control system rather than the system in current use had considerable potential to closely match dis-charge at the downstream check structures with those ordered by water users while maintaining the water level throughout the length of the canal.
