Core Fueling of DEMO by Direct Line Injection of High-Speed Pellets from the HFS

Antonio Frattolillo, Larry R. Baylor, Francesca Bombarda, Stephen K. Combs, Christian Day, Peter T. Lang, Silvio Migliori, Bernard Pegourie, Bernhard Ploeckl

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Pellet injection represents to date the most realistic candidate technology for core fueling of a demonstration fusion power reactor tokamak fusion reactor. Modeling of both pellet penetration and fuel deposition profiles, for different injection locations, indicates that effective core fuelling can be achieved launching pellets from the inboard high field side at speeds not less than 1 km/s. Inboard pellet fueling is commonly achieved in present tokamaks, using curved guide tubes; however, this technology might be hampered at velocities ≥1 km/s. An innovative approach, aimed at identifying suitable inboard 'direct line' paths, to inject high-speed pellets (in the 3 to 4 km/s range), has recently been proposed as a potential complementary solution. The fuel deposition profiles achievable by this approach have been explored using the HPI2 simulation code. The results presented here show that there are possible geometrical schemes providing good fueling performance. The problem of neutron flux in a direct line-of-sight injection path is being investigated, though preliminary analyses indicate that, perhaps, this is not a serious problem. The identification and integration of straight injection paths suitably tilted may be a rather difficult task due to the many constraints and to interference with existing structures. The suitability of straight guide tubes to reduce the scatter cone of high-speed pellets is, therefore, of main interest. A preliminary investigation, aimed at addressing these technological issues, has recently been started. A possible implementation plan, using an existing Italian National Agency for New Technologies, Energy and Sustainable Economic Development-Oak Ridge National Laboratory facility is shortly outlined.
Original languageEnglish
Pages (from-to)1429 - 1435
Number of pages7
JournalIEEE Transactions on Plasma Science
Issue number5
Publication statusPublished - 1 May 2018
Externally publishedYes


All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics
  • Condensed Matter Physics

Cite this

Frattolillo, A., Baylor, L. R., Bombarda, F., Combs, S. K., Day, C., Lang, P. T., Migliori, S., Pegourie, B., & Ploeckl, B. (2018). Core Fueling of DEMO by Direct Line Injection of High-Speed Pellets from the HFS. IEEE Transactions on Plasma Science, 46(5), 1429 - 1435.