Compact Fusion Reactor, CFR Thomas J. McGuire, Ph.D. [email protected] LOCKHEED MARTIN © 2015 Lockheed Martin Corporation. All Rights Reserved. • LM Philosophy, need and mission – 1.3 B without electricity, 18% of world, EIA International Energy Outlook 2013 (IEO2013) – +56% energy consumption and +93% electricity generation from 2010 to 2040, EIA International Energy Outlook 2013 (IEO2013) – @ $3/W, $210B/yr in new electrical power plant sales alone • Compact, elegant…rapid development, short cycles. High beta • Favorable reactor geometry – Similar method: J. P. Freidberg, F. J. Mangiarotti, and J. Minervini, Physics of Plasmas 22, 070901 (2015). • Nominal Reactor Design Point – 200 MW Thermal, T = 14 keV, n = 1.8·10^20 m^-3, V = 30.8 m^3. – 1 m blanket, 80%/20% FLIBE/Steel, 3.2 g/cc, 4 MW/m^2 neutron wall load – Core: 5.2 m diameter by 15.2 m long, 230 mt – B_β=1 = 1.4 T, p = 7.8 atm, B_mirror = 4.2 T, 9 MA mirror current • Conservative Reactor Design Point – 200 MW Thermal, T = 14 keV, n = 6.3·10^19 m^-3, V = 247 m^3. – 2 meter blanket, 5 g/cc, 1 MW/m^2 neutron wall load – Core: 10.5 m diameter by 30.5 m long, 1900 mt – B_β=1 = 0.84 T, p = 2.8 atm, B_mirror = 5.0 T, 20 MA mirror current Diagram annotations: natural divertor, diamagnetic plasma sheath, superconducting magnets, steady-state stable DT fusion plasma, neutral beam injectors, blanket absorbs neutrons to breed fuel and transfer heat to turbines. © 2015 Lockheed Martin Corporation. All Rights Reserved. • Vacuum field is a set of linear ring cusps encapsulated by a bottle field – Beta = 1 surfaces are in-board of cusps – Line-averaged global interchange stability is achieved, only locally-bad curvature in ring cusps, ∫ dl / B Diagram / Plots: - Magnetosphere/null Line, Stability Boundary, Limiter - Stability Plot for Outer Mirror Flux Tubes: Stable, dV/dr < 0 - Stability Plot for Inner, Recirculation Flux Tubes: Stable Everywhere, dV/dr < 0 - Beta = 1 design line, center line, cylindrical HTS superconducting coils (10 MA, 1 MA, 7 MA, 1 MA, 4.3 MA) © 2015 Lockheed Martin Corporation. All Rights Reserved. • Vacuum field is a set of linear ring cusps encapsulated by a bottle field – Beta = 1 surfaces are in-board of cusps – Line-averaged global interchange stability is achieved, only locally-bad curvature in ring cusps • Interchange pushes plasma into magnetic wells, observed in initial low power experiments – Heating creates plasma at discrete locations in volume, propagates along field lines – Pressure gradients should kick off turbulence that will organize a diamagnetic plasma – As plasma pressure increases, Beta = 1 sheath boundary should 'inflate' and fill up chamber volume. – Need sufficient heating to fully ionize background gas and to raise temperature to levels that reduce CX collisions and mirror losses. Equations & Loss Channels: - Magnetized sheath losses: P_S ≈ (L_M * r_p * n_s^2) / B_p ≈ (r_p^2 * n^2) / T^(1/2) P_i,s = 3/2 * e(T_i + eφ_p) * L_i [W], P_e,s = 3/2 * e(T_e - eφ_p) * L_e [W], L_s = (n_s * V_s) / (2 * τ_ii), τ_ii = 2·10^13 * (μ^(1/2) * T_i^(3/2)) / (n_s * λ_ii) [s] - Unmagnetized ring cusp losses to coil supports: P_R ≈ (r_p * n * T^2) / B_p ≈ r_p * n^2 * T^(1/2) P_i,R = 3/2 * e(T_i + eφ_p) * Γ_i,R * A_R * %i · S = (24 * sqrt(2) / sqrt(pi)) * e(T_i + eφ_p) * sqrt(eT_i / m_i) * (n_R / n) * (e * n_i / n_s) * (N_s * a_R / R_s) * S * δ_R [W] P_e,R = 3/2 * e(T_e - eφ_p) * Γ_e,R * A_R * %i · S = (24 * sqrt(2) / sqrt(pi)) * e(T_e - eφ_p) * sqrt(eT_e / m_e) * (n_R / n) * (e * n_e / n_s) * (N_s * a_R / R_s) * S * δ_R [W] Annotations: neutral beam heat, ring cusp losses to stalks, axial cusp losses, sheath losses exit axially, diffusion loss to coil, plasma sits in magnetic wells, trapped magnetized sheath, center line. © 2015 Lockheed Martin Corporation. All Rights Reserved. • Steady-state – Need a consistent equilibrium solution, complex kinetic plasma • Main losses – Magnetized sheath, ion losses from positive plasma – Unmagnetized ring cusp losses to supports – Charge exchange losses – Line radiation – Bremmstrahlung radiation – Unmagnetized cusp losses on axis – Diffusion across magnetic fields to walls • Ionization and heating – ECRH – LaB6 – Plasma gun – Electron or ion beam – Neutral beam initialization – Alpha product self-heating • Biggest challenges and questions – Cusp behavior – drives scaling and shielding requirements – Shielding implementation – 90% reduction needed for hybrid gyro – Microinstabilities, ExB and stability during inflation transient – Plasma facing surfaces, neutron damage and blanket design – Tritium lifecycle and containment Scaling formula: Q = P_f / P_L = (1.3 * e * Y * <σv>) / [ 1.6·10^-33 * (n_s / n)^2 * (1 / (r_p * B_p)) (Sheath) + 2·10^-44 * (n_R / n) * (S / (r_p^2 * B_p^3)) * T^3 (Support) + 5.2·%I * Q_k + 8.9·10^-38 * Z_eff * T^(1/2) (Radiation terms) ] Annotations: alpha heating from DT fusion plasma, neutral beam heat, trapped magnetized sheath, ring cusp losses to stalks, axial cusp losses, sheath losses exit axially, diffusion loss to coil, center line. © 2015 Lockheed Martin Corporation. All Rights Reserved. • Progression of fast experiments with parallel sub-system work – T4 – Investigate CFR plasma configuration – T5 – Demonstrate high Beta – T6 – Demonstrate high power (1 MW), high temperature (1 keV) – T7 – Demonstrate reactor conditions with Deuterium plasma – T8 – Demonstrate ignited DT plasma for short durations (<10 sec) • Parallel sub-system development – Plasma simulation – Neutral beam heating development – Superconducting magnetic field coils – Internal coil support shielding – Blanket design and power plant design • Engineering and product development, towards a T-X Reactor – Energy conversion cycle – Materials, tritium cycle, servicing – Regulation, environmental impact, ITAR, military applications © 2015 Lockheed Martin Corporation. All Rights Reserved. • T4 goal: Investigate CFR plasma configuration – V_plasma = 0.33 m^2, V_chamber = 2 m^3. – n_background = 3·10^18 m^-3 D2 gas – 0-15 kW 2.4 GHz ECRH, axial injection – Peak mirror magnetic field 0.6 T, shot duration ~1 sec. • Results, 482 shots to date – Observe plasma organization in magnetic wells – ECRH cut-off limits ability to reach full ionization, <10% – At higher powers, observe outer regions filling with plasma – Peaked density profiles in core, flat T_e with increased power – Typical n = 10^16 m^-3 - 10^17 m^-3, T_e = 10-25 eV, τ_E = 4-100 μsec Diagnostics listed: Microwave interferometer, Diamagnetic loops, Bolometer, Soft x-ray - UV spectrometer, Hard x-ray, Visible spectroscopy, High-speed imaging, Langmuir probe, B-dot probe. Plots: (far left) FastCam visible imager, (left) ion density vs. probe location, (center) electron temperature vs. power at different probe locations. Error bars represent the standard deviation of values calculated from I-V sweeps taken multiple times during the run. (right) line-averaged density from interferometer averaged over shot. Error bars are the result of signal noise and magnetic field effects. Blue line is a linear fit to the data. © 2015 Lockheed Martin Corporation. All Rights Reserved. T5 plan • Fully ionized plasma, LaB6 source and washer gun • Improved diagnostics – Langmuir probes, b-dot probes, ES analyzer, spectroscopy, Thomson scattering, flux loops • Neutral beam heating development, hot high beta • Alternate heating: axial electron and ion beam heating • Simulations – Plasma equilibrium – HPC PIC plasma studies, high Beta cusp behavior, inflation transients, magnetic shielding – Blanket design, lightweight and low-cost designs • Magnetic support shielding and superconducting coil design • Currently hiring in Palmdale, CA. 14 open positions – Plasma experimentalist, plasma theory, pulsed power, beam, laser, electronics, mechanical © 2015 Lockheed Martin Corporation. All Rights Reserved. Lockheed Martin Star Logo