Nuclear-Chicago Model NC-205 BF₃ Counter (ca. 1955-1965)

This neutron detector was produced by the Nuclear-Chicago Company of Des Plaines, Illinois. I have no information about this specific instrument, but the following general information comes from a Nuclear-Chicago bulletin that appeared in the December 1961 issue of Nucleonics:  "BF₃ gas proportional neutron detectors may be obtained in practically every size and shape. Their pressures range up to three atmospheres. All are sturdily constructed for long, rugged use. . . . NC 218 is a large cosmic ray neutron detector having a guard ring insulator which assures low background. NC 251 is a general purpose thermal neutron detector with a ceramic insulator and stainless steel anode for high temperature operation."  The presence of the exposed evacuation/fill tube leads me to suspect that it most likely dates from the late 1950s.

Size:  ca. 5" long and 5/8" in diameter

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