The upgraded LAPD is the centerpiece of the Basic Plasma Science User Facility. It is a significant enhancement of the Large Plasma Device (LAPD) at UCLA. The machine occupies an entire floor in the new Science and Technology Building (completed in May of 1998), a modern research facility with high electrical power handling capabilities (30 MW). Present, ongoing activities in LAPD are sponsored by ONR, DOE, and NSF.
The upgraded LAPD is 19 meters long with a 75 centimeter diameter plasma column and will be capable of operating with a confining magnetic field up to 3.5 kiloGauss (steady-state). The plasmas will be generated by two independent cathodes that will permit the creation of controlled plasma flows. Presently the device has one cathode in operation. The new machine is designed so that the length of the plasma column can varied and the radial density profiles can be tailored to study various physical processes that depend on transverse or axial gradients in density and temperature. The confining magnetic field can also be controlled and varied to generate various mirror and cusp configurations. Fully ionized plasmas are routinely available with density in excess of 5x1012 cm-3 and electron temperatures in the 10-20 eV range. A view of the plasma machine is shown in the figure above. In the first weeks of operation we have generated He and Ne plasmas with discharge currents of up to 11 kA.
We envision the plasma science facility as a place to perform frontier-level experiments that require physical conditions not suitable for small devices. The facility provides an environment in which teams with complementary expertise (e.g., Laser Induced Fluorescence or High Power RF) can come together to attack problems that they would not pursue individually. If this approach is successful it will not only advance the discipline at the technical level, but it may also change the way in which plasma science is done in the future. A properly nurtured facility would enable qualified scientists from small institutions access to state-of-the-art hardware and a broad range of plasma conditions in which to exert their creativity. The facility would also be highly beneficial for stimulating cross-disciplinary training of graduate students and postdoctoral scholars and could provide a much needed integration of laboratory and space researchers.