LLNL Home S&TR Home Subscribe to S&TR Send Us Your Comments S&TR Index
Spacer Gif

Spacer Gif


Mark A. Rhodes, Scott N. Fochs
Apparatus and Method for Electrical Insulation in Plasma Discharge Systems
U.S. Patent 6,605,901 B1
August 12, 2003
An apparatus and method to contain plasma at optimal fill capacity of a metallic container. The invention uses anodized layers to form the internal surfaces of the container volume. Bias resistors are calibrated to provide constant current at variable voltage. The voltages of the metallic container can be adjusted relative to the voltage of an anode by choosing the appropriate values of the bias resistors. In this way, the optimal plasma fill can be achieved while minimizing the chance that the breakdown voltage of the anodized layer is reached.

Babak Sadigh, Thomas J. Lenosky, Tomas Diaz de la Rubia
Method for Enhancing the Solubility of Dopants in Silicon
U.S. Patent 6,627,522 B2
September 30, 2003
A method for enhancing the equilibrium solid solubility of dopants in silicon, germanium, and silicon–germanium alloys. The method involves subjecting silicon-based substrate to biaxial or compression strain. It has been determined that boron solubility was largely enhanced (more than 100 percent) by a compressive biaxial strain, based on a size-mismatch theory, since the boron atoms are smaller than the silicon atoms. The large enhancement or mixing properties of dopants in silicon and germanium substrates is primarily governed by their charge and, to second order, by their size mismatch with the substrate. Furthermore, the dopant solubility enhancement with strain is most effective when the impurity’s charge and the size mismatch favor the same type of strain. Thus, the solid solubility of small p-type dopants (such as boron) and large n-type dopants (such as arsenic) can be raised most dramatically by appropriate biaxial (compressive) strain. The solubility of a large p-type dopant (such as indium) in silicon will be raised because of its size mismatch with silicon, which favors tensile strain, while its negative charge prefers compressive strain. Thus, the two effects counteract each other.

Chris Darrow, Tino Seger
Interrogation Cradle and Insertable Containment Fixture for Detecting Birefringent Microcrystals in Bile
U.S. Patent 6,628,387 B2
September 30, 2003
A transparent flow channel fluidly communicates a fluid source and a collection reservoir. An interrogating light beam passes through a first polarizer having a first plane of polarization. The flow channel is orthogonal to the light beam. The light beam passes through a fluid sample as it flows through the flow channel. The beam is then filtered through a second polarizer that has a second plane of polarization rotated 90 degrees from the first plane of polarization. An electronic photodetector aligned with the light beam signals the presence of birefringent microcrystals in the fluid sample by generating voltage pulses.

A disposable containment fixture includes the flow channel and the collection reservoir. The fixture is adapted for removable insertion into an interrogation cradle that includes optical and data-processing components. The cradle rigidly positions the centerline of the flow channel orthogonal to the light beam.

Richard Freeman Post
Inductrack Configuration
U.S. Patent 6,629,503 B2
October 7, 2003
A simple permanent-magnet-excited maglev geometry provides levitation forces; it is stable against vertical displacements from equilibrium but is unstable against horizontal displacements. An Inductrack system is then used with this system to effect stabilization against horizontal displacements. The Inductrack system also provides centering forces to overcome centrifugal forces when the vehicle is traversing curved sections of a track or when another transient horizontal force is present. In some proposed embodiments, the Inductrack track elements are also used as the stator of a linear induction-motor drive and braking system.

Richard Freeman Post
Inductrack Magnet Configuration
U.S. Patent 6,633,217 B2
October 14, 2003
A magnet configuration comprising a pair of Halbach arrays magnetically and structurally connected together. The Halbach arrays are positioned with respect to each other so that a first component of their fields substantially cancels at a first plane between them and a second component of their fields substantially adds at this first plane. A track of windings is located between the pair of Halbach arrays, and a propulsion mechanism is provided for moving them along the track. When the arrays move along the track and the track is not located at the first plane, a current is induced in the windings, which then exerts a restoring force on the pair.

Back | S&TR Home | LLNL Home | Help | Phone Book | Comments
Site designed and maintained by IBIS Internet Publishing Team

Lawrence Livermore National Laboratory
Operated by the University of California for the U.S. Department of Energy

UCRL-52000-03-12 | December 3, 2003