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Latest News
CFS working with NVIDIA, Siemens on SPARC digital twin
Commonwealth Fusion Systems, a fusion firm headquartered in Devens, Mass., is collaborating with California-based computing infrastructure company NVIDIA and Germany-based technology conglomerate Siemens to develop a digital twin of its SPARC fusion machine. The cooperative work among the companies will focus on applying artificial intelligence and data- and project-management tools as the SPARC digital twin is developed.
J. T. Hogan, D. L. Hillis, J.D. Galambos, N. A. Uckan, K. H. Dippel, K. H. Finken, R. A. Hulse, R. V. Budny
Fusion Science and Technology | Volume 19 | Number 3 | May 1991 | Pages 1509-1512
ITER | Proceedings of the Ninth Topical Meeting on the Technology of Fusion Energy (Oak Brook, Illinois, October 7-11, 1990) | doi.org/10.13182/FST91-A29555
Articles are hosted by Taylor and Francis Online.
Many studies have shown the importance of the ratio τHe/τE in determining the level of He ash accumulation in future reactor systems. Results of the first tokamak He removal experiments have been analyzed, and a first estimate of the ratio τHe/τE to be expected for future reactor systems has been made. The experiments were carried out for neutral-beam-heated plasmas in the TEXTOR tokamak at KFA Jülich. Helium was injected both as a short puff and continuously and subsequently extracted with the Advanced Limiter Test-II (ALT-II) pump limiter. The rate at which the He density decays has been determined with absolutely calibrated charge-exchange spectroscopy and compared with theoretical models, using the Multiple Impurity Species Transport (MIST) code. An analysis of energy confinement has been made with the Princeton Plasma Physics Laboratory (PPPL) TRANSP code, to distinguish beam from thermal confinement, especially for low-density cases. The ALT-II pump limiter system is found to exhaust the He with a maximum exhaust efficiency (eight pumps) of ∼8%. We find 1< τHe/τE < 3.3 for the database of cases analyzed to date. Analysis with the International Thermonuclear Experimental Reactor (ITER) TETRA systems code shows that these values would be adequate to achieve the required He concentration with the present ITER divertor He extraction system.