PHASMA

While it was not my responsibility to design the experiments that will occur inside PHASMA, it is helpful to have a basic understanding of the experimental procedure. The center chamber, which is held to near-vacuum pressure is surrounded by two sets of multiple electromagnets. A gas is pumped into the vacuum chamber, and then an electrical charge created by a matching box causes the gas to change states into highly charged plasma. The plasma is contained to the center region of the chamber by the magnetic field generated by the electromagnets. Experiments are performed using sets of physical and optical (laser) probes mounted to the chamber. PHASMA was specifically created to allow for a process called planar LIF, where laser light sent through the plasma is analyzed by a camera system instead of a single point detection system.

One of my first responsibilities in the lab was to redesign the "pump cart". PHASMA is split up into multiple sections, so that the experiment is easy to disassemble and repair if something breaks. Each section is placed on a pair of steel "tracks" that each cart can roll up and down. The pump cart sits at the end of the experiment and stores two vacuum pumps and one roughing pump, as well as the control systems for each, custom gate-valve interlock panels, and an electronic pressure gauge. When I began work, the team had just learned that the cart was designed incorrectly, and did not match the rest of the experiment. Using Solidworks, I fixed the broken component of the design and redesigned the cart to reuse old material, so that a new cart could be constructed both quickly and cheaply. My design for the cart is currently in use.

A major component of the optical probe system is the optical table. High-powered lasers are kept on expensive, vibration-damping tables that weigh roughly 1 ton. These tables have previously been extremely difficult to move around. To allow for increased mobility, I designed a cart meant to reuse material from an old experiment that an optical table could be placed on. The steel, wheeled cart currently holds the optical table, two lasers, and their control systems. The only cost of the cart was the labor required to weld it.

As much of the mechanical systems of PHASMA were completed, my job transitioned to the design of its control system. I created a custom Windows PC to meet the specifications of the lab instruments and experimental concepts, which included a 48 terabyte high-speed storage system, PCI and PCIe slots, dozens of USB and serial ports, and more. I then created an "in-lab" network, allowing instant access to instrumentation in other locations around the lab from the control computer. For the final few weeks of my internship, I began developing a LabVIEW control software designed to run all components of the lab system. Upon the completion of my job term, the LabVIEW system was able to turn on the magnet systems, generate a plasma, and had some basic analytical code. Using old software meant for a different experimental setup, the PC was capable of collecting all data the lab had previously been capable of collecting.