An Interesting Poster to look at from the Tri Alpha Energy Team in California

Summary of C-2W Field-Reversed Configuration Experiment Diagnostic Systems and Results
Abstract
Plasma Jet Diagnostics
M. C. Thompson, T. Schindler, H. Gota, S. Putvinski, M. Tuszewski, M. W. Binderbauer, and the TAE Team
TAE Technologies, Inc., 19631 Pauling, Foothill Ranch, CA 92610 C-2W Diagnostic Overview
Spectroscopic Diagnostics
Magnetic Diagnostics:
 22 combined B-dot / flux loops, plus 22 linear array B-dots.
 64 three-axis Mirnov probes with dual frequency coils.
 152 external flux loops and B-dots.
 The four main zones of C-2W has 40 + types of diagnostics:
 Core plasma inside the FRC separatrix.
 Open-field-line mirror-confined plasma in the scrape-off layer (SOL) and jet.
 Rapidly expanding plasma in the inner divertors and/or end divertors.
 FRC formation sections.
Combined Analysis of Magnetic Diagnostics, Thomson Scattering, and Interferometry
Courtesy – E. Granstedt
Core Thomson Scattering:  New Nd:YAG laser with two modes:
30 pulses at 1kHz, ≥ 2 J / pulse
6 pulses 10-20 kHz, ≥ 2 J / pulse
 Scattered light collection at 16 points
spread between the core and SOL.
 Up to 480 Te measurements per shot.
Fast Cameras:
 High speed camera imaging from five locations throughout the machine.
 Most have motorized filter wheels.
 Reconstruction of plasma density profiles via Bayesian methods provided by Google collaborators. Courtesy – P. Norgaard, M. Dikovsky, and T. Baltz (Google)
Mid-Plane FIR Interferometry:
 14 chords of Far Infrared (FIR) laser at 433 μm.
 High sensitivity and full coverage into the scrape- off layer (SOL).
 Polarimetry Function: 7 sensitive to Bθ , 7 sensitive to Bθ and Bz.
 Avantes Survey Spectrometers provide emission spectrum and impurity trends throughout
C-2W:
Ti gettering
CV
Inner Divertor
Ti gettering
Ti gettering
 Doppler spectroscopy provides both main ion and impurity ion velocity and temperature.
Outer Divertor
Main Hydrogen / Deuterium Ions
O4+
TAE Technologies, Inc. studies the evolution of advanced beam-driven field-reversed configuration (FRC) plasmas sustained by neutral-beam injection. Ongoing operations on the new C-2W device (also called Norman) focus on FRC heating and diamagnetic current build up [1]. Data on the FRC plasma is provided by a comprehensive suite of diagnostics including over 700 magnetic sensors, four interferometry systems, multi-chord FIR polarimetry, two Thomson scattering systems, survey spectroscopy measurements, impurity and majority ion CHERS, multiple fast imaging cameras, end loss analyzers, multiple bolometer systems, and fusion product detectors. Many other sophisticated diagnostics are also in preparation and commissioning including: reflectometry, neutral particle analyzers, and FIDA. Most of these diagnostic systems are new designs built using experience and data from the preceding C-2U [2] experiment. TAE’s diagnostics development program also works on novel systems including new ways to measure FRC internal magnetic fields.
[1] M.W. Binderbauer et al., AIP Conf. Proc. 1721, 030003 (2016) [2] M.C. Thompson et al., Rev. Sci. Instrum. 87, 11D435 (2016)
Plasma Jet Interferometer
 Up to 6 chords across the jet near the mirror region between confinement vessel and inner divertor.
 Duel wavelength setup to handle large density swing between FRC translation and sustainment:
 CO2 laser at 10.6 μm
 Microwave sources at 1 mm
Courtesy – R. Smith
Jet Thomson Scattering
 New Nd:YAG laser that generates 4 pulses at 100 Hz with ≥ 2 J / pulse.
 Scattered light collection at 5 points spread across the plasma jet in the mirror region.
Jet and Core Thomson lasers can be swapped in case we need higher resolution in the jet.
Courtesy – E. Park, K. Zhai, and T. Schindler
Divertor Diagnostics
Bolometry Systems
 Linear array of narrow  Wide view bolometers
view bolometers provide the longitudinal plasma radiation profile.
mounted at the end of the vessel measure total plasma radiation.
 Multipole chords of filtered bolometry provide the transverse plasma radiation profile.
Intersecting lines of sight Edge lines of sight
Courtesy – A. DuBois and T. Dehaas
 End Loss Analyzer measurements of ion currently and power density deposited on
the outer electrodes.
divertor
Divertor Diagnostics Include:
 Magnetic Probe and Flux Loops  Rogowski Coils
 End Loss Analyzers
 High Speed Cameras
 Survey and Doppler Spectroscopy
Shape & Position
Density & Fluctuation
Temperature & Radiation
Fast Ions & Neutrals
North/South Formation Flux Loops
CO2 Interferometer
Thomson Scattering
Electrostatic NPA
Formation High Speed Camera
Far-Infrared Interferometer
Bolometer Arrays
Electromagnetic NPA
Confinement Bz Probes
Thomson Scattering
Doppler Spectroscopy
Neutral Particle Bolometer Arrays
Confinement Flux Probes
Dispersion Interferometers
Survey Spectrometers
Pyro Bolometers
Mirnov Probe Arrays
Microwave Interferometers
VUV Spectrometer
SEE Detectors
Longitudinal Bolometer Arrays
Cut-Off Reflectometer
Line Ratio Spectroscopy
Neutron Detectors
Transverse Bolometer Arrays
Fluctuation Reflectometer
Impurity Line Monitors
Proton Detectors
Bremsstrahlung Arrays
Mirnov Probe Arrays
Bremsstrahlung Arrays
Dα Monitors
End-View High Speed Camera
Triple Probes
Impurity line monitors
Dα /Dβ Intensity Ratios
Side-View High Speed Camera
Mach Probes
He-Jet Mach Nozzle
Fast Ionization Gauges
Multi-Chord Interferometry
Gunderstrup Probe
Langmuir Probes
Residual Gas Analyzers
Additional TAE Posters:
Neutral Distribution from Imaging Erik Granstedt PP11.00084
Neutral Beam Shine Through Diag. James Titus PP11.00085
Energy Distribution of Lost Ions Martin Griswold PP11.00086
Langmuir Probe Measurements Ami DuBois PP11.00087
Electron Temperature Profiles Kan Zhai PP11.00088
Additional TAE Posters:
Open Field Line Electron Temperature Eli Parke PP11.00089
Mid-Plane and Jet Interferometry Roger Smith PP11.00090
Measurement and Analysis of Zeff Marcel Nations PP11.00091
Open Field Line Ion Flows Daniel Sheftman PP11.00093
Fluctuations Wavenumber Spectrum Lothar Schmitz PP11.00094
Abridged Table of Current and Planned C-2W Diagnostics Capabilities
Courtesy – M. Nations
Courtesy – D. Gupta
Courtesy – D. Osin
Courtesy – M. Griswold