DHS HS-STEM Internship Summary Report

Abstract

I had the opportunity to work at Lawrence Livermore National Laboratory within the MEMS, Electronics, and Photonics Technologies group. I worked under the direct supervision of Dr. Adam Conway and Dr. Erik Swanberg on a semiconductor based gamma ray detector. My work involved automating the experimental setup and data analysis portion of the project to alleviate the researcher’s busy schedules. A semiconductor is a material that has conductivity in between a metal and ceramic. In layman’s terms, if you provide it with just enough energy, charge can flow inside of the material. If we impose some form of ionizing radiation such as a gamma ray, we can detect the amount of energy imparted on the system by measuring the amount of charge produced in the material. Figure 1 outlines the process that a semiconductor undergoes to allow us to detect ionizing radiation. Certain materials properties make them ideal for gamma ray detection such as the average atomic number, carrier properties, resistivity, and bandgap energy. I was working with Thallium Bromide (TlBr) detectors for room temperature detection of gamma rays, specifically looking at how different metal electrodes affected the stability of our system. My work involved automating the stress and voltage tests applied to the TlBr detectors and allowing for easy analysis of the data to determine if the system was still functional.