Theory Weekly Highlights for November 2005

November 18, 2005

The Linux installation of SCOPE, which is a plotting program appropriate for rapid 2D plots, has been updated to use the new distributed MDSplus infrastructure, and the PAD tool, which is often used in conjunction with SCOPE, has also been installed. PAD is a “scratch pad” for sharing data references between SCOPE, the MDSplus TRAVERSER and with other users. The upgrade improves the performance of SCOPE and provides a chance to test out distributed MDSplus. Instructions and demonstrations are available at:

November 11, 2005

The theoretical basis for an exotic new pellet acceleration technology using microwave power from MW gyrotron sources has been developed that could pave the way for high-speed > 3 km/s inner-wall pellet injection on ITER. This technology represents a ten-fold increase in pellet velocity from the present ITER design. The method uses a composite pusher-pellet module that absorbs microwave power and converts it to a high-pressure, high-temperature (un-ionized) gas by means of eddy current dissipation inside small conducting particles embedded homogeneously behind the pellet in the D2 ice pusher. The microwave power is delivered to the pellet-pusher module along a waveguide, which also functions as the pellet guide tube; the power is transmitted through a transparent (diamond/sapphire) window/plug, which also absorbs the pellet recoil momentum during acceleration. A US patent application “Microwave-Powered Pellet Accelerator,” No. 11/256,662, was filed on October 21, 2005 by P.B. Parks and F. W. Perkins, and a paper to Nuclear Fusion is being submitted.

November 04, 2005

Equilibrium radial profile corrugations at low order singular surfaces were first discovered in the GYRO simulations for Fred Hinton's APS 2003 invited talk. The corrugations on the scale of several ion gyroradii are most pronounced in the electron temperature gradient. As predicted, the corrugations are largest for the 2/1 surfaces as the qmin = 2 surface enters the DIII-D tokamak at a mid-radius. Max Austin's APS 2005 invited talk presented DIII-D electron temperature gradient time traces from the ECE diagnostic which have the same size/location and signature (q=2/1 & bump-dip-bump) corrugations as the “full physics” GYRO qmin = 2 simulations. While the corrugations have a signature similar to a 2/1 MHD island, the GYRO simulations show quite clearly that the corrugations are quasi-equilibrium components of the zonal flows and not magnetic islands. This is confirmed by magnetic diagnostics. The DIII-D data suggests that the qmin = 2 corrugations are the trigger for the ITB that follows.

The Second post APS Error Magnetic Field Workshop organized by Lang Lao of General Atomics was successfully held at the Adam's Mark Hotel in Denver, CO on October 28, 2005 with more than 40 participants. The PDF files of the Workshop presentations can be found at

These highlights are reports of research work in progress and are accordingly subject to change or modification