Mori received a Bachelor of Science from the University of California, Berkeley in 1981. He then went to the University of California, Los Angeles (UCLA) and obtained a Master of Science and a Doctor of Philosophy (Ph.D.) in 1984 and 1987 respectively. For his Ph.D. in Electrical Engineering, Mori was supervised by plasma physicists Francis F. Chen, John M. Dawson and Chandrashekhar J. Joshi,Mori, W. B. (1987) Theory and Simulations on Beat Wave Excitation of Relativisitic Plasma Waves, Ph.D. Thesis. all of whom were noted for winning the James Clerk Maxwell Prize for Plasma Physics. Mori then remained at UCLA, and has been there ever since.
