The Hybrid Reactor Project Based On The Straight Field Line Mirror Concept
2012 (English)In: Fusion for Neutrons and Subcritical Nuclear Fission: Proceedings of the International Conference / [ed] Jan Källne, Dimitri Ryutov, Giuseppe Gorini, Carlo Sozzi, Marco Tardocchi, 2012, 173-185 p.Conference paper (Refereed)
The straight field line mirror (SFLM) concept is aiming towards a steady-state compact fusion neutron source. Besides the possibility for steady state operation for a year or more, the geometry is chosen to avoid high loads on materials and plasma facing components. A comparatively small fusion hybrid device with "semi-poor" plasma confinement (with a low fusion Q factor) may be developed for industrial transmutation and energy production from spent nuclear fuel. This opportunity arises from a large fission to fusion energy multiplication ratio, Q(r) = P-fis/P-fus >> 1. The upper bound on Q(r) is primarily determined by geometry and reactor safety. For the SFLM, the upper bound is Q(r)approximate to 150, corresponding to a neutron multiplicity of k(eff) =0.97. Power production in a mirror hybrid is predicted for a substantially lower electron temperature than the requirement T-e approximate to 10 keV for a fusion reactor. Power production in the SFLM seems possible with Q approximate to 0.15, which is 10 times lower than typically anticipated for hybrids (and 100 times smaller than required for a fusion reactor). This relaxes plasma confinement demands, and broadens the range for use of plasmas with supra-thermal ions in hybrid reactors. The SFLM concept is based on a mirror machine stabilized by qudrupolar magnetic fields and large expander tanks beyond the confinement region. The purpose of the expander tanks is to distribute axial plasma loss flow over a sufficiently large area so that the receiving plates can withstand the heat. Plasma stability is not relying on a plasma flow into the expander regions. With a suppressed plasma flow into the expander tanks, a possibility arise for higher electron temperature. A brief presentation will be given on basic theory for the SFLM with plasma stability and electron temperature issues, RF heating computations with sloshing ion formation, neutron transport computations with reactor safety margins and material load estimates, magnetic coil designs as well as a discussion on the implications of the geometry for possible diagnostics. Reactor safety issues are addressed and a vertical orientation of the device could assist passive coolant circulation. Specific attention is put to a device with a 25 m long confinement region and 40 cm plasma radius in the mid-plane. In an optimal case (k(eff) = 0.97) with a fusion power of only 10 MW, such a device may be capable of producing a power of 1.5 GW(th).
Place, publisher, year, edition, pages
2012. 173-185 p.
, AIP Conference Proceedings, ISSN 0094-243X ; 1442
Mirror machine, hybrid reactor, neutron source
Engineering and Technology
Research subject Engineering Science with specialization in Science of Electricity
IdentifiersURN: urn:nbn:se:uu:diva-181208DOI: 10.1063/1.4706867ISI: 000306895100020ISBN: 978-0-7354-1038-1OAI: oai:DiVA.org:uu-181208DiVA: diva2:556107
International Workshop on Fusion Neutrons and Subcritical Nuclear Fission (FUNFI), SEP 12-15, 2011, Varenna, ITALY