Quadrant of Zero Energy Thermonuclear Assembly (ZETA)
1957
1957
1990-1991
1961-1962
1956-1960
1995
1920-1979
1955-1965
1960-1969
1952
1970-1982
circa 1960s
1946-48
1960-1970
1948-50
1946-48
1982
1955-1960
1946-53
1946-50
1946-78
1946-53
1940-43
1970-1978
1980
1980
1950-1970
1950-1970
circa 1975
circa 1980
circa 1960s
circa 1989
1980
circa 1975
1986