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A Materials Evaluation Neutron Source Based on the Gas Dynamic Trap (DTNS) One Element in an Urgently Needed Comprehensive Fusion Materials Program. Based on a Mirror Status Workshop Berkeley, CA. Sept. 8-9, 2008 25 Participants - 6 Labs. and 5 Universities - Japan & Russia
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A Materials Evaluation Neutron Source Based on the Gas Dynamic Trap (DTNS)One Element in an Urgently Needed Comprehensive Fusion Materials Program Based on a Mirror Status Workshop Berkeley, CA. Sept. 8-9, 2008 25 Participants - 6 Labs. and 5 Universities - Japan & Russia T. C. Simonen, Chair Renews Workshop March 2-6, 2009
The Simple Axisymmetric Mirror A Physics & Engineering Game Changer • Simple magnet geometry stabilized by plasma exhaust • Physics established: Novosibirsk GDT Device – 60% beta, Te, classical • Extrapolates to a Dynamic Trap D-T Neutron Source (DTNS) • ~ 2 MW/m2 Neutron Flux, ~2 m2 Area, ~100 Liter Volume • Simple Geometry, Ease of Construction & Maintenance • Addresses Greenwald Gaps 10 & 13 and Initiative 7 Neutron Source
GDT at Novosibirsk, Russia12 m Long with Large End Tanks to Decouple Te 3
One Version of DTNS Showing Magnets, Shielding ,Neutral Beams, and Material Samples(Bobouch, Fusion Science & Tech. 41 (2002) p44)
Neutron Flux Scales With Te to 4 MW/m2(for various NBI energies)
DTNS Could Produce ITER-Like Neutron Energy Spectra(Fischer, A.Moslang, A.Ivanov, FE&D 48 (2000) p.307)
DTNS Would Operate at Higher Magnetic Field, Neutral Beam Energy, and Power than GDT
DTNS Has Two Test Zones • Neutron Flux concentrates in regions of beam ion Turning Points • One Zone could test many material samples • One Zone could test Sub-components
Small Material Sample Test Assembly(Holds ~8,000 Temp. Controlled Specimens)ref: U. Fisher, A. Moslang, A.A. Ivanov, FE&D 48 (2000) p307
Monte Carlo Calculation Indicates Uniform Radial-Axial Neutron Flux(r-uniformity < 5%/cm, z-uniformity < 0.1%/cm)
Summary– The DTNS is an Attractive D-T Neutron Source That Closes Gaps 10 & 13 and Initiative 7 for Materials Testing • ITER-Like Neutron Energy Spectrum • Produces 1-4 MW/m2 • Provides ~2 m2 Test Area • Provides ~100 Liter Test Volume • Uniformity < 5%/cm
Suggested Next Steps • Collaboration with Novosibirsk GDT • Diagnostics (Thomson Scattering, …) • GDT-Upgrade (4 MW to 10 MW) • Theory-Modeling to • Extrapolate to DTNS (Te, MHD, DCLC, TPM ) • Seek More Efficient Design (end cells) • Deploy US Theory Capabilities (e.g. UTexas, LLNL, LANL, Lehigh, etc, etc) • Initiate DTNS Design • Construct DTNS (could be phased)
Additional Benefits of DTNS Activity • DTNS Physics Has Much in Common with Other Confinement Systems • Tests Existing Modeling Capability in Very Simple Geometry • More Efficient DTNS (end cells) Leads to a Fusion-Fission Hybrid • Benefits Outside Magnetic Fusion • Fosters International Collaboration
References • Gas dynamic trap as high power 14 MeV neutron source, P.A Bagryansky , et. al. Fusion Engineering and Design 70 (2004), p13-33 • Assessment of the gas dynamic trap mirror facility as intense neutron source for fusion material test irradiations, U. Fischer, A. Moslang, A.A. Ivanov, Fusion Engineering and Design, 48 (2000) p307-325