Model of BF3 neutron proportional Geiger counter
1954
1954
1960-1970
1968
1967
1992
1995
1958
1978-95
1970
1996
1947
1956
1954
1950-1970
1978-95
1964
1960-1970
1978-1995
1967
1978-95
1967
1977-1978