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PV-WAVE Helps UCLA Researchers The User Developed at the University of California at Los Angeles’s Physics and Astronomy Department, the Large Plasma Device (LAPD) is a unique tool for researching the fundamental properties of naturally occurring plasmas. This machine is the premier instrument in the world for the detailed study, under controlled conditions, of fundamental plasma processes that play a major role in the behavior of naturally occurring plasmas as are encountered in the neighborhood of the earth, the interplanetary medium, the sun and in astrophysical environments. The LAPD is instrumented with computerized data acquisition probes and advanced visualization computers that permit the study of the temporal evolution of complicated three-dimensional processes that presently constitute the frontier of space plasma research. This large research device is extremely flexible in its operation, able to accommodate several simultaneous experiments (through 434 access ports), and generate research-grade plasmas at a one Hertz repetition rate around the clock. These properties make the LAPD ideally suited for broadly-based collaborative experiments on a scale never before attempted by the worldwide basic plasma science and space communities. If properly supported, this device has the potential to move the understanding of the behavior of naturally occurring plasmas to a very high level limited only by the imagination of its users. The LAPD was made possible by a National Science Foundation (NSF) grant to the principal investigators, Drs. Walter Gekelman, James Maggs and George Morales. And the UCLA administration has made extraordinary financial contributions toward the success of the LAPD. An entire floor in the University’s new Science and Technology Research Building, a modern research facility with high electrical power handling capabilities, has been allocated to the LAPD. Furthermore, the visionary and steady support provided by the Office of Naval Research (ONR) over the past ten years has permitted the development of the LAPD program to a level of international prominence. Presently, ongoing research activities in LAPD are sponsored by ONR, NSF and the Department of Energy. The LAPD is 18 meters long with a 75 centimeter diameter plasma column and is capable of operating with a confining magnetic field up to 4 kiloGauss (steady-state). The plasmas are generated by two independent cathodes that permit the creation of controlled plasma flows, a common feature encountered in near-earth plasmas and which plays a key role in space weather. LAPD experiments have a major impact on the development of plasma theory, simulation and modeling because they generate unambiguous quantitative measurements of phenomena that thus far have not been tested. In essence, this device has the potential to solidify the foundations of plasma theory by weeding out failing ideas, while simultaneously stimulating its development in different directions with the discovery of new phenomena. Another important consequence of LAPD activities is the establishment of a close link between the researchers that make observations on board rockets and spacecraft and laboratory scientists. It is envisioned that through collaborative LAPD experiments, a new generation of space researchers will be trained who will acquire a solid background in plasma physics and space phenomenology. The LAPD program also involves educational outreach through the existing Los Angeles-based alliance of high school teachers, which was developed by Principal Investigator Walter Gekelman. Dr. Gekelman hopes the LAPD will expose high school students and their teachers to the excitement and challenges faced by working scientists studying space plasmas. The Problem Of paramount importance in a well-diagnosed basic physics experiment is a state-of-the-art data acquisition system. The LAPD laboratory has assembled hardware and software that enables the real-time analysis of experimental data and the storage and manipulation of very large datasets. The LAPD’s data acquisition system is flexible enough to perform real-time manipulations of incoming data, and provide rapid turnaround for data reduction and display. The front-end of the system consists of a PC-based Labview data acquisition system with interfaces that control analog to digital converters, programmable amplifiers, stepping motor controllers, and arbitrary waveform generators. This system is, in turn, networked to four Alphastations, three DECstations, a Sun Microsystems Ultra-2, a Silicon Graphics Indigo-2, and a Silicon Graphics Octane. Most of these computers can render three-dimensional images of data and rotate and zoom in real-time. This capability is indispensable for visualizing the complex data sets that are generated from the experiments conducted in the LAPD. The workstations have up to 1 Gbyte of RAM and the local lab hard disk space exceeds 200 GB with high-speed network access to Terabytes of archival tape storage on the main campus. Of course, all this computing power is only useful if it is supported by equally powerful software. The LAPD lab utilizes a number of internally-written data analysis and data acquisition programs, but, according to Dr. Gekelman, it also needed a commercially-available software solution that offered a strong combination of visualization techniques, numerical analysis routines, and flexibility. The Solution In their search for a data visualization solution, Dr. Gekelman and his colleagues turned to PV WAVE, the flagship product from Visual Numerics, Inc. PV-WAVE is an open environment for developing and deploying Visual Data Analysis (VDA) applications that help customers turn raw data into meaningful information. These VDA applications let users visualize and manipulate complex or extremely large data sets to detect and display patterns, trends, anomalies, and other vital information. PV-WAVE includes hundreds of mathematical and statistical analysis routines from Visual Numerics’ IMSL Numerical Libraries, as well as image processing, signal processing, mapping, and general data manipulation features. Engineers, scientists, business analysts, and software developers access this robust and extensive set of functions through an array-oriented programming language. PV-WAVE also includes advanced graphical user interface development tools that facilitate the construction of intuitive front-ends, making the product’s functionality easily accessible to others in an organization. “We’ve been using PV-WAVE in our lab to filter and analyze experimental data for nearly ten years now. It does a great job of handling very large datasets, which are common in our experiments,” Dr. Gekelman said. “Not only does it offer powerful visualization tools and ease of-use, PV-WAVE’s inclusion of the IMSL mathematical and statistical analysis routines allows us to do elaborate calculations, without changing environments. That’s a huge benefit when both time and money are short.” Benefits & Results Dr. Gekelman said the benefits of using PV-WAVE are many. “We generate extremely large datasets from a Labview-based data acquisition system, and PV-WAVE handles large volumes of data very efficiently,” he said. “In addition, we generate volumetric data and we use PV-WAVE to digitally filter it, reformat it, and do various types of analysis.” Dr. Gekelman also believes that PV-WAVE’s inclusion of the IMSL mathematical and statistical analysis routines is a significant benefit. “We routinely use the IMSL functionality, which is embedded into PV-WAVE, to perform sophisticated theoretical calculations. We used to use straight Fortran or C to do our calculations, but we have come to prefer PV-WAVE over these languages for doing theory.” Finally, Dr. Gekelman cited PV-WAVE’s built-in functionality and flexibility as very important to his work. “It has many useful built-in functions, such as simple debugging procedures, which accelerate the data analysis process. And the software’s flexibility allows us to make graphs of any variable in the calculation on the fly, letting us see instantly if the program is performing as expected.” Client Satisfaction Based on the fact that Dr. Gekelman has used PV-WAVE for nearly ten years, one would have to assume that he is a very satisfied customer. But if there are any doubts, perhaps his own words will eliminate them: “Because I work for a large, prestigious university, I have access to just about any data visualization and analysis software out there. In my many years of experience, I have not found any that performs as well as PV-WAVE. It is an invaluable piece of technology in our lab, and one that I would quickly recommend to other scientists and engineers.” |