U Penn Abstract - A. Liu

Throughout the six weeks of the QuarkNet program, I worked mostly on the hardware side of the project. The goal was to build a detector that detects and measures cosmic rays. Upon first using the advanced lab equipment, I was introduced to things like scintillators and photomultiplier tubes that I had not known about beforehand. First, we checked for light leaks and found the optimum voltage for each scintillator with a Cesium-137 source. When that was done, we tested the 32 photomultiplier tubes in two chambers to determine which ones were not producing signals. This process took many weeks because some tubes needed to be soldered or replaced. Soldering fixed the tubes that had broken connections to capacitors, and tubes with broken pins or no continuity were replaced. Repeated testing of the tubes was done to determine the ones that produced a signal on the oscilloscope. Some of the tubes gave no signals even when they were fixed or replaced with a working tube. Troubleshooting, such as checking for proper grounding, gas leaks and current draw, was accomplished to ultimately have two fully working chambers. Many of the tubes had to been run at a much higher voltage than originally thought. From the entire hardware process, I got a closer look at electronics and the wiring of the cosmic ray detector. In addition to possessing a deeper understanding of the detectors, I was exposed to the scientific research process. I learned that results don’t just come in ones. Sometimes, we had to go over and redo tests many times, but the end result was always worthwhile. Most importantly, I learned to move on from minor problems when larger unseen issues were looming. I also developed a focused attention for assembling the sensitive instruments and for soldering tiny connections. The patience required for careful handling and fixing of the tubes was an important part of the learning process.

In addition to working on our own project, I was exposed to other areas of physics and astronomy. We attended daily lectures by professors and specialists. The lectures were diverse, from biophysics to gravitational lensing. Furthermore, we attended tours of other labs, including the BLAST lab, the Singh Center for Nanotechnology, the robotics lab, and Brookhaven National Laboratory in New York. It was also very useful to be able to discuss problems and receive help from the University of Pennsylvania staff and faculty throughout the program.

Before I started QuarkNet, I did not know how much I would come to love the kind of work that the people in the High Energy Physics Department do. Throughout the six weeks, I was able to utilize my scientific knowledge and programming skills to work with three other students on a higher level physics project. Having once regarded research as an esoteric process, I was thrilled to discover that research is a means to satisfy one’s curiosity of the surrounding world and to share it with others. The skills and knowledge I have gained at QuarkNet will surely help me in my future endeavors.