Fusion Science and Technology
Fusion Science and Technology
Theoretical Aspects of Spheromaks
Principal Investigators: Morse
The spheromak is a very compact magnetic configuration to confine hot plasmas in a fusion reactor, but one at very early stages of development. Recent theoretical work suggests that energy confinement in spheromaks is far better than previously believed. Experiments on the SSPX spheromak at Livermore are addressing this and other questions about spheromaks. Recent studies indicate that the “nuclear island” cost for a spheromak fusion reactor would be much less than that for the tokamak concept that is the mainline research effort today.
Gas Dynamics and Liquid Response in Inertial Confinement Fusion Target Chambers
| This research studies x-ray driven ablation, blast propagation and transient condensation for removing vapor generated in inertial confinement fusion target chambers. Another component of the project studies liquid jet phenomena in vacuum environments. The work focuses both on issues important to chamber dynamics in the National Ignition Facility, and to future inertial fusion energy power plants. Research support comes from the Department of Energy Office of Fusion Energy Science. |
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Magnetic Confinement Fusion: BCTX Section
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Overview The UCBNE department is home of the Berkeley Compact Toroidal Experiment (BCTX). Operated by Professor Ed Morse, the BCTX is a spheromak experiment with the unique capability of producing auxiliary-heated spheromaks. The machine has a lower hybrid drive system which can deliver up to 20 MW of RF power at 432 MHz to the plasma for a 100 us pulse length. |
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Given complete coupling of RF energy into the plasma, this represents
sufficient energy to heat the plasma electrons to 1 keV. Experiments
at such temperatures offer the opportunity to explore ideal MHD
pressure limits and energy confinement regimes not accessible in
other devices.
Installed diagnostics on this machine include Thomson scattering
for electron temperature, magnetic field B-dot loops, a laser interferometer
for density measurement, several spectrometers for impurity ion
spectroscopy, and an ion Doppler temperature measurement system.
Current experiments are focused on determining electron heat confinement
in spheromaks using the RF heating source as a heat pulse. To date,
electron temperatures up to 150 eV have been measured in BCTX.
Inertial Confinement Fusion: Target Design Section
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Overview At Berkeley, students participate in the design of fusion targets with teams at the LBNL Accelerator and Fusion Research Division. |
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Diagnostics for the D-III-D Tokamak
The D-III-D Tokamak, operated by General Atomics in San Diego, is currently upgrading a diagnostic called Fast Motional Stark Effect (MSE). This diagnostic allows the magnetic fluctuations inside the plasma to be monitored without the insertion of probes into the plasma. This information is valuable for unlocking the mystery of heat confinement in the tokamak. Magnetic fluctuations might play a significant role in causing the anomalously large heat conduction in magnetically confined plasma such as a tokamak. A doctoral student from UCBNE is currently developing this MSE diagnostic and taking data with it on the D-III-D Tokamak.
Heavy Ion Fusion
Investigation of effects of propagation of neutrals generated by impact of halo ions on wall surfaces, leading to formation of electrons and non beam ions which can disrupt beam propagation. Collaboration with the Virtual National Laboratory, supported by the Department of Energy.
Theoretical Investigation of Plasma Turbulence using Galerkin MHD
A method of modeling dynamic nonlinear magnetohydrodynamic (MHD) behavior of fusion plasma has been developed based on a decomposition of fields and velocities using eigenfunctions of the curl operator. This technique has been applied to dynamical modeling of spheromak plasma. A mathematical solution of the eigenfunctions of the curl for cylindrical and annular cylindrical geometries has been obtained for the general non-axisymmetric states. Methods of determining the presence of magnetic stochasticity based on the spectra found in dynamical modeling of these plasmas are being studied. Current effort is focussed on developing a curl-eigenfunction basis for realistic noncircular toroidal geometries such as ITER, and applying these techniques to tokamak plasma dynamics.
