| Affiliation: | 1. Department of Physics, University of California, Berkeley, CA 94720-7300, USA;2. Department of Physics, California State University, East Bay, Hayward, CA 94542-3084, USA;3. Department of Physics, Boston University, Boston, MA 02215, USA;4. Helmholtz Institute Mainz, Johannes Gutenberg University, 55099 Mainz, Germany;5. School of Instrumentation Science and Opto-Electronics Engineering, Beihang University, Beijing 100191, PR China;6. Nuclear Science Division, Lawrence Berkeley National Laboratory , Berkeley, CA 94720, USA |
