 Isidor Isaac Rabi ( / ˈrɑːbi / ; born Israel Isaac Rabi , 29 July 1898 – 11 January 1988 ) was an American physicist and Nobel laureate , recognized in 1944 for his discovery of nuclear magnetic resonance , which is used in magnetic resonance imaging . He was also one of the first scientists in the US to work on the cavity magnetron , which is used in microwave radar and microwave ovens . 
