MoNA: aka R2D2 ( Radiation Reading Da -Vinci-lady-named Device)

1. What's this photo about? A title and description can provide essential detail about this photo. MoNA: aka R2D2(Radiation Reading Da-Vinci-lady-named Device) The Lepretons: Calvin M., Alex A., Clayton S., and Alex C. • What Is MoNA: • Modular Neutron Array, made up of scintillator bars. • Scintillator bars are made of plastics with light atomic weights. The lighter atoms are used in detection because they react more to incoming particles than heavier atoms react. • Each MoNA bar detects neutrons which cause interactions that excite the particles in the scintillator. When this happens, photons of light are emitted. • These photons are multiplied and analyzed to determine the neutron’s position, energy and direction of travel. Experiment 1: Detecting particles with the Modular Neutron Array (MoNA) In this experiment, we measured events from a single MoNA Bar using an oscilloscope to determine the position of a radioactive source. The oscilloscope receives data on the timing and voltage of an event on both sides of the MoNA bar. We began by taking measurements of the time and voltage of signals. Next, we used that information to find the position of the radioactive source by plotting the known positions and their values on a graph, drawing a line through the points, and finding where on the line the measurements from the unknown source was located. We identified a position within 5cm of the source. This error was in part due to the small number of events we analyzed. Experiment 2: Acquisition Lab Instead of taking measurements on an oscilloscope, we analyzed the data with a program called SpecTcl. Researchers use this tool in their real experiments because it allows them to analyze an enormous number of events quickly and accurately. The program creates spectra from radiation in the MoNA bars and defines parameters based on the time and energy of the event. Once we learned how to use the program, we analyzed the spectra to calibrate it. We once again created graphs based on the measurements and the error the program gave us. When a source was placed in an unknown location, we collected data from the program and plotted it on the graphs to find the location of the source. Our placement was within 2.5cm of the actual placement. Time vs. Position Experiment 3: Cosmic Ray Detections In this experiment, we examined cosmic rays. We were particularly interested in the angle the cosmic rays traveled. We were able to measure this by analyzing the difference in the position where the muons were recorded in the top and bottom bars of MoNA. When we plotted the results and discovered that the distribution of muons generally follows a cos2θ graph. This is most likely because the muons travelling directly down through the atmosphere have less atmosphere to go through and therefore scatter less than muons and cosmic rays travelling at an angle. Special thanks to JINA, NSCL, MSU, Zach Constan, NSF, and, most of all, the taxpaying citizens of the United States of America for making this experience possible.