LISA - Laser Integrated System Architecture

Copper Vapor (Photo credit: Ray Tracing)

Between 1984 and 1986, although I was an employee of Martin Marietta Energy Systems (MMES) which operated DOE facilities in Oak Ridge, I worked on various Laser scientific and cost modeling codes supporting the Atomic Vapor Laser Isotope Separation (AVLIS) project going on at Lawrence Livermore National Laboratory (LLNL) in Livermore, California. Just out of college, the most important software that I wrote during this period was called the Laser Integrated System Architecture, or LISA.  The LLNL AVLIS design called for green light from copper vapor lasers to be used to pump highly tuned dye lasers in order to deliver the required light necessary to separate isotopes using selective ionization. AVLIS was being considered by DOE as an advanced enrichment process to replace the aging Gaseous Diffusion facilities and had been selected over the Molecular Laser Isotope Separation (MLIS) process that I had worked on previously as a co-op student.

LISA was the brainchild of Ralph Patterson.  He had the idea for an interactive computer aided laser system design and analysis tool that supported the design and simulation of AVLIS plants.   When it was finished, it was about 7500 lines of extended pascal code written to run on an expensive Apollo Engineering Workstation.  It had two basic modes of operation.  The first was a computer aided “plant design” mode which given the laser system delivery requirements, design constraints and input parameters, would automatically design the Laser system of an AVLIS plant:  the laser power distribution, the details of beam combination, the numbers of copper amplifiers and oscillators, the number and sizes of dye amplifiers and the dye flow loop specs. The second mode of operation was a simulation of the AVLIS laser system which given the architecture and input constraints calculated the delivered light and made predictions about costs.  In order to write the code, I spent countless long hours working closely with Ralph Patterson in order to learn the processes involved.

Early on, I determined that the graphic library available on the Apollo to be inadequate for the requirements of LISA, so I used the basic primitives from the graphic system, called the Graphics Primitives Resource (GPR), and wrote my own entire graphics library system.  My library included everything required for LISA including two and three dimensional graphics and plotting routines making the software very portable.  It also included some unique and very flexible routines for laying out and organizing the drawing canvas. After I left the project, the person that inherited the job of maintenance for the LISA software was easily able to port LISA to run on an HP workstation because of the design of this library.  Years later, I also ported the graphics library from pascal into Ada using ReGIS graphics on DEC vt240 and vt340 terminals.

I think some of my finest ever solo software programming work was accomplished during these two years as part of LISA. I was especially proud of the supporting graphics library system that I had designed and coded.  However, because of its nature and purpose, very few people would ever get to see or run the LISA software. After this solo work, I yearned to work on a larger software project as part of a software team. So, I returned to Oak Ridge for my next assignment and joined a plant wide Computer Integrated Manufacturing (CIM) effort that was starting at the Y-12 facility, but that’s another story.

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