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An exploding water plasma experiment at UCLA investigated the expansion and morphology of a fireball with and without an external magnetic field. Diagnostics include photographs and movies (which may be downloaded) acquired with a framing camera, magnetic probes, and visible light spectra. The expansion and internal magnetic fields are very different from the unmagnetized case when a magnetic field of order 300G is applied along the expansion axis. Visible light spectra are brighter and additional lines are seen in the presence of the magnetic field. The experiment can serve as a platform for studies of interfacial mixing and possibly shed light on very different processes such as laser target physics.

Following the damaging 17 January 1994 (4:30:55 AM PST; Mw 6.7) Northridge earthquake, several California State University at Northridge (CSUN) research and outreach projects were initiated in seismology. The Northridge earthquake was located (34°12.80′N, 118°32.22′W; depth 18.4 km) one mile south-southwest of Northridge and 20 miles westnorthwest of Los Angeles. The event was produced by a south-dipping, blind thrust fault (Northridge thrust; also known as the Pico thrust). The earthquake was felt by approximately 12 million people within an area of about 212,000 km2 from the San Fernando Valley to Los Angeles. The damage estimate was approximately $20 billion, including $350 million at CSUN (Woods and Seiple, 1995). The outreach project involved the Los Angeles Physics Teachers Alliance Group (LAPTAG) in the early 1990's as an alliance of more than 20 high schools, Santa Monica College, and the University of Southern California (USC) (Gekelman, 1998). One of the LAPTAG science projects involved an inexpensive PC-based seismometer to establish a ten-school seismic network (Figure 1). The goal of this project was to instruct teachers and their students how science is conducted in teams, and to provide lectures to integrate the physics principles into geophysical problems. The high school seismic data files were analyzed by the students and then were transferred to the UCLA Physics Web site (http://coke.physics.ucta.edu/taptag), where they could interchange …

An RF amplifier system was designed and is under construction at the UCLA Basic Plasma Science Facility. The system is designed to output 200 kW peak RMS power at 1% duty cycle with a 1 Hz rep rate at frequencies of 2-6 MHz. This paper describes the RF amplifier system with preliminary benchmarks. Current design challenges and future work are discussed.

A novel angular motion feedthrough to vacuum has been designed and implemented at the Large Plasma Device at UCLA. The mechanism is easy and inexpensive to build. If linear motion capability is added, then one can arbitrarily and precisely position a probe within a specific volume in a vacuum chamber.

Laboratory measurement of small-scale ( approximately 1 mm) magnetic phenomena over an extended area is a challenge requiring precise diagnostics. We present a novel two dimensional magnetic probe platform capable of directly measuring the magnetic field over a 36 cm(2) region at spatial resolutions better than 1 mm. The platform is discussed in the context of an experiment at the Large Plasma Device facility at UCLA, designed to measure the magnetic interaction between two counterpropagating laser-produced plasmas. The use of a precise, repeatable positioning platform enables the recovery of information about the interaction using cross-correlation techniques.

Hardware and software for a high-speed, pulsed-data-acquisition system are described. Data can be obtained via any device attachable to a VXI crate, GPIB controller, or directly via serial or parallel ports. Stepper motors controlled via serial port automate probe movement. LabVIEW and custom C++ modules are used to handle setup, data gathering and processing, and user interface. Experimental parameters can be controlled at each point via any GPIB-ready device. © 1997 American Institute of Physics.

A CAMAC‐based LSI microcomputer coupled to a VAX minicomputer with a high (200 kbyte/s) transfer rate network make possible real‐time data processing and control of a data‐intensive plasma physics experiment. The system is constructed out of reliable, commercially available components. Most of the network software is written in fortran and is easy to maintain and modify. A description of its four software layers and illustrations of the type of experiments it has been used on are presented.

The limitations of previous target plasmas and the requirements for improved target plasmas are discussed. Two distinctly different approaches were pursued successfully. The first approach represents a relatively minor modification of the discharge techniques previously used in the QUIPS facility. Utilizing a combination of the pulsed rf plasma production techniques developed under the previous year's contract with a new pulsed magnetic field technique, we have produced a target plasma possessing all of the desirable properties of previous target plasmas, with an order of magnitude higher fractional ionization and improved boundary conditions. The second target plasma production technique is based on plasma production by intense, short pulse laser irradiation of a solid target. The resulting blowoff plasma expands into vacuum and, after a suitable delay time, is irradiated by a pulsed mirowave beam. The blowoff plasma properties and preliminary results of microwave interaction experiments are described.