1. Field-Particle Correlation Experiments on DIII-D Frontiers Science Proposal
Under weakly collisional conditions, collisionless interactions between electromagnetic fields and individual particles lead to particle energization
This process leads to perturbations in the particle velocity distribution functions that are correlated with the electromagnetic fields
Spatially coincident measurements of the electromagnetic fields and particle velocity distribution functions can be used to compute directly the rate of particle energization
Well diagnosed DIII-D shots may enable the application of this field-particle correlation method to explore the particle energization arising from the damping of turbulent fluctuations in the edge region
Field-particle correlations can identify heating mechanism

2. Context: Diagnosing Particle Energization using Field-Particle Correlations
Main Scientific Challenge
Determining particle energization using
measurements of field and distribution functions
Distinguishing different mechanisms of particle
energization using velocity-space signature
Relevance
Particle energization and plasma heating
impacts a wide range of systems, from solar
corona to black hole accretion disks to fusion
plasmas
Techniques used to date
Nonlinear kinetic simulations of electrostatic waves
Nonlinear gyrokinetic simulations of turbulence
Measurements of electron acceleration in LAPD Expt
MMS spacecraft measurements

3. Context: Diagnosing Particle Energization using Field-Particle Correlations
Scientific progress to date
Development of theoretical foundation for the
field-particle correlation method
Application to analyze ion and electron heating
in gyrokinetic turbulence and reconnection sims
Analyzed electron acceleration in LAPD Expts
Analysis of electron heating in magnetosphere
Key gap issue
Application of method to experimental
measurements on DIII-D will pave the way for
widespread use of the technique to determine
directly particle energization in expts
Method can be used to distinguish different
mechanisms of particle energization
Experiments on plasma turbulence,
anomalous ion heating, and electron
acceleration will benefit from using this method

4. DIII-D Proposal Determining Particle Energization
Scientific question to be tested on DIII-D
Directly diagnose the conversion of
electromagnetic energy into particle energy
and determine mechanism responsible
Directly determine heating of particles
in edge region using field-particle correlation
Experimental Technique
Measure particle distribution functions
and electromagnetic field fluctuations at
the same position in the DIII-D discharge
Analysis done / planned
Nonlinear gyrokinetic simulations of
turbulence can predict heating mechanism
Velocity space signature generated by
field-particle correlation analysis points to
energization mechanism

5. DIII-D Proposal Determining Particle Energization
Why DIII-D? / Why now?
DIII-D boast sophisticated
diagnostics to measure
electromagnetic fluctuations and
particle velocity distributions.
Fundamental new approach to
study particle energization in
edge region and the responsible mechanism can be pioneered on DIII-D
Related studies elsewhere
Fast ion studies on DIII-D already use similar approaches to study wave-particle interactions
Application of innovative field-particle correlation method to electron acceleration in LAPD Expts
Use of field-particle correlations to determine heating in space plasmas
Impact of successful result
Development of new experimental method to determine rate of particle energization in edge and the physical mechanism responsible

6. Experiment Details Field-Particle Correlations
Key hardware elements required
Neutral Beam Injection for fast ions
3D coils to achieve shape of field
to enable in situ measurements
Key measurements required
ECE diagnostic
Toroidal mode magnetic field diagnostics
B dot measurement in space and time
Interferometers
Electric field measurements
Fast ion diagnostics
Particular preparation necessary
Determine shot parameters that yield interesting ion or electron heating regimes
Determine what spatially coincident particle and field measurements can be made on DIII-D
Theory to apply field-particle correlations to distributed measurements

7. Experiment Team University personnel DIII-D personnel
Greg Howes, U Iowa, Nonlinear kinetic plasma theory and simulation
Kristopher Klein, U Michigan, Kinetic plasma theory and simulation
Mark Koepke, WVU, Experimental Alfven modes, nonlinear dynamics
Jose Boedo, UCSD, Experimental edge physics and ion confinement
Bill Heidbrink, UC Irvine, Fast particle and TAE experiments on DIII-D
DIII-D personnel
George McKee, GA, Experimental fusion turbulence
Auna Moser, GA, Experimental divertor physics