Diagnostics
This diagnostic uses pulsed lasers to measure the edge neutral density.
TALIF
This device is located in Madison, WI and uses a magnetic mirror configuration
The Wisconsin high-temperature superconducting (HTS) Axisymmetric Mirror (WHAM)
This instability is a direct result of magnetic reconnection.
tearing mode (will accept sawtooth as well)
This fusion device currently holds the record for longest fusion pulse.
WEST (W Environment in Steady-state Tokamak) @ 1337 seconds (22 minutes)
These instabilities act as a pressure relief valve and damage the plasma-facing components.
edge localized modes (ELMs)
Name a difference between Thomson scattering and Laser-induced fluorescence (besides that they measure electrons and atoms)
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First device to achieve "burning plasma"
NIF
This is one of the biggest --if not the biggest--impediments to tokamak fusion devices
runaway electrons
What is the mathematical expression for the triple product?
n*T*tau_E
Which figure of merit must be > 1 for a fusion power plant to produce more energy than it consumes?
fusion gain, Q = P_(fusion,out)/P_(in)
These measure the total radiated power from the plasma.
bolometers
Researchers at Columbia University recently used what to mitigate runaway electrons in DIII-D?
Helicon waves (or can answer with whistler waves)
This is the most problematic instability in magentic mirrors configurations
flute instability/ interchange instability
What process must two atomic nuclei undergo to surpass the Coulomb barrier in order to fuse?
Quantum tunneling
Draw a double null divertor configuration
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This class of diagnostics is capable of capturing the rapid temperature and density changes associated with a sawtooth crash in a tokamak
soft x-ray diagnostics
What quantity is injected into the HIT-SI plasma to sustain the spheromak and drive it toward a relaxed Taylor state?
magnetic helicity
Name this process :
escaped fusion fuel hits the walls --> returning to the plasma as cold neutrals --> cooling the fuel as a whole --> fusion reactions are reduced
Recycling
This phenomenon (caused by the radial electric field) increases confinement time by reducing particle transport enabled by turbulent eddies.
shear flow
Why is current drive important in tokamaks?
It allows the plasma current to be sustained without relying entirely on transformer-driven inductive current
Name at least two diagnostics that use the neutral beam injection as part of the diagnostic itself.
Beam emission spectroscopy, charge exchange recombination spectroscopy, motional Stark effect, fast ion D-alpha (FIDA)
These are a wave/instability that occur when the toroidal geometry of a tokamak modifies the Alfven continuum and creates a frequency gap in which these modes exist.
Toroidal Alfvén eigenmodes (TAEs)
This is one of the major technical challenges in inertial confinement fusion (ICF) and is required to prevent uneven compression and loss of fusion performance.
capsule symmetry
What is the main advantage of using hydrogen-boron as fusion fuel (as opposed to DT)
aneutronic --> no thermal cycle
A charged particle becomes magnetically trapped and bounces between regions of stronger magnetic field while simultaneously drifting toroidally. What is this motion called?
banana orbit