Hagelstein was given the task of simulating the X-ray laser process on LLNL's supercomputers. His program, known as XRASER for "X-Ray laser", eventually grew to about 40,000 lines of code. He received his master's degree in 1976 and took a full-time job at the lab, intending to lead the development of a working laser. The idea was to use the lab's powerful fusion lasers as an energy source, as Hagelstein and Wood had suggested in their review paper. Hagelstein used XRASER to simulate about 45 such concepts before he found one that appeared to work. These used the lasers to heat metal foils and give off X-rays, but by the late 1970s, none of these experiments had been successful.