TAE Technologies' research is devoted to producing high temperature, stable, long-lived field-reversed configuration (FRC) plasmas by neutral-beam injection (NBI) and edge biasing/control. The newly constructed C-2W experimental device (also called "Norman") is the world's largest compact-toroid (CT) device, which has several key upgrades from the preceding C-2U device such as higher input power and longer pulse duration of the NBI system as well as installation of inner divertors with upgraded electrode biasing systems. Initial C-2W experiments have successfully demonstrated a robust FRC formation as well as its translation into the confinement vessel through the newly installed inner divertor with adequate guide magnetic field. They also produced dramatically improved initial FRC parameters with higher plasma temperatures (Te up to 300 eV; total electron and ion temperature >1.5 keV) and more trapped flux (up to ~15 mWb, based on rigid-rotor model) inside the FRC immediately after the merger of collided two CTs in the confinement section. As for effective edge biasing/control on FRC stabilization, a number of edge biasing schemes have been tried via open-fieldlines, in which concentric electrodes located in both inner and outer divertors as well as end-on plasma guns are electrically biased independently. As a result of effective outer-divertor electrode biasing alone, FRC plasma diamagnetism duration has reached up to ~9 ms which is equivalent to C-2U plasma duration. Magnetic field flaring/expansion in both inner and outer divertors plays an important role in creating a thermal insulation on open-field-lines to reduce a loss rate of electrons, which leads to improvement of the edge as well as core FRC confinement properties.

The operational conditions of the solar-thermal receiver for a Brayton cycle engine are challenging, and lack a large body of operational data unlike steam plants. We explore the receiver's fundamental element, a pressurized tube in time varying solar flux for a series of 30 yr service missions based on hypothetical power plant designs. We developed and compared two estimation methods to predict the receiver tube lifetime based on available creep life and fatigue data for alloy 617. We show that the choice of inelastic strain model and the level of conservatism applied through design rules will vary the lifetime predictions by orders of magnitude. Based on current data and methods, a turbine inlet temperature of 1120 K is a necessary 30-yr-life-design condition for our receiver. We also showed that even though the time at operating temperature is about three times longer for fossil fuel powered (steady) operation, the damage is always lower than cyclic operation using solar power. Downloaded From: http://solarenergyengineering.asmedigitalcollection.asme.org/ on 03/27/2013 Terms of Use: http://asme.org/terms

TAE Technologies, Inc. (TAE) is pursuing an alternative approach to magnetically confined fusion, which relies on field-reversed configuration (FRC) plasmas composed of mostly energetic and well-confined particles by means of a state-of-the-art tunable energy neutral-beam (NB) injector system. TAE’s current experimental device, C-2W (also called ‘Norman’), is the world’s largest compact-toroid device and has made significant progress in FRC performance, producing record breaking, high temperature (electron temperature, T e > 500 eV; total electron and ion temperature, T tot > 3 keV) advanced beam-driven FRC plasmas, dominated by injected fast particles and sustained in steady-state for up to 30 ms, which is limited by NB pulse duration. C-2W produces significantly better FRC performance than the preceding C-2U experiment, in part due to Google’s machine-learning framework for experimental optimization, which has contributed to the discovery of a new operational regime where novel settings for the formation section and the confinement region yield consistently reproducible, hot, and stable plasmas. An active plasma control system has been developed and utilized in C-2W to produce consistent FRC performance as well as for reliable machine operations using magnets, electrodes, gas injection, and tunable NBs. The active control system has demonstrated stabilization of FRC axial instability. Overall FRC performance is well correlated with NBs and edge-biasing system, where higher total plasma energy is obtained by increasing both NB injection power and applied-voltage on biasing electrodes. C-2W divertors have demonstrated a good electron heat confinement on open-field-lines using strong magnetic mirror fields as well as expanding the magnetic field in the divertors (expansion ratio > 30); the energy lost per electron ion pair, η e ∼ 6–8, is achieved, which is close to the ideal theoretical minimum.

Proton-boron (p11B) fusion is an attractive potential energy source but technically challenging to implement. Developing techniques to realize its potential requires first developing the experimental capability to produce p11B fusion in the magnetically-confined, thermonuclear plasma environment. Here we report clear experimental measurements supported by simulation of p11B fusion with high-energy neutral beams and boron powder injection in a high-temperature fusion plasma (the Large Helical Device) that have resulted in diagnostically significant levels of alpha particle emission. The injection of boron powder into the plasma edge results in boron accumulation in the core. Three 2 MW, 160 kV hydrogen neutral beam injectors create a large population of well-confined, high -energy protons to react with the boron plasma. The fusion products, MeV alpha particles, are measured with a custom designed particle detector which gives a fusion rate in very good relative agreement with calculations of the global rate. This is the first such realization of p11B fusion in a magnetically confined plasma.

Great advancements in modern field-reversed configuration (FRC) experiments motivated the development of a 14-chord three-wave far infrared (FIR) laser interferometry and polarimetry diagnostic system, which can provide simultaneous high temporal resolution measurements of density and Faraday rotation profiles with high accuracy. The unique challenges facing FIR diagnostics in high beta FRC plasmas are the extremely small (<0.5°) Faraday rotation angles, and severe laser beam refraction effects due to high density gradient and choice of long wavelength. The diagnostic system design and development are described with methods to overcome the challenges, and initial experimental data are also presented.