Complex sentence: In 1944, shortly after moving to the University of California, Berkeley to participate in the Manhattan Project, developing the atomic bomb, he invented the scintillation counter, a device widely used to this day to measure ionizing radiation.
Split into simpler sentences: In 1944, he moved to the University of California, Berkeley to participate in the Manhattan Project, developing the atomic bomb. This device is widely used to this day to measure ionizing radiation.