The PI and graduate students will make precise measurements of the basic properties of free neutrons to improve our understanding of the fundamental forces in nature. Neutrons, trapped in atomic nuclei along with protons, make up about one-half of the observable matter in the Universe. The group will participate in the UCNtau+ (Ultra-Cold Neutron Lifetime) experiment which hopes to make the most precise measurement of the lifetime of the free neutron. This will improve our understanding of the weak nuclear force that plays an important role in understanding the Big Bang at the beginning of the universe as well as nuclear energy generation in the sun and stars. Participation in these experiments by graduate students helps provide the nation with a highly trained workforce in Nuclear Science and Technology, with applications in medicine, new technology, national defense as well as basic science. The PI and graduate students will use novel techniques to perform precision measurements with trapped spin-polarized Ultra-Cold Neutrons (UCN). For the UCNtau+ experiment, which uses a bath-tub size array of permanent magnets to levitate the neutrons and prevent them from being absorbed by material walls, the PI and students will work on data-taking and data-analysis. Participation in this experiment allows graduate students to learn low-temperature cryogenic techniques and quantum control of neutron spins while also helping to provide the nation with a highly trained workforce in N