Possible Clues:

• Unit of length equal to a femtometre
• Eponym of a physics lab near Chicago
• Enrico ___ , Italian-American physicist, creator of the first nuclear reactor, d. 1954
• Noted physicist
• Los Alamos scientist
• Finding Einstein relatively misleading for beginners, I must be a physicist
• Element #100 is named for him
• Big name in nuclear physics
• Golfer misses, covering tiny distance
• Rome-born physicist