The Discovery of the Magnetic Hyperfine Interaction in the Mössbauer Effect of ⁵⁷ Fe

Abstract

It was the autumn of 1959 and the Iron Age, as reckoned on the Mössbauer calendar [9.1], was just dawning. The phenomenon of recoilless gamma-ray absorption, discovered by Rudolph Mössbauer [9.2] in Ir, had been confirmed the previous summer [9.3, 4], and we had heard via the grapevine [9.5] that the effect was indeed much larger and more sensitive in the nucleus ⁵⁷Fe. These new devel opmen ts were a favorite topic at the lunch tables of the Argonne National Laboratory. What could be done with this sensational new effect? Were we on the threshold of exciting new discoveries? One of the intriguing ideas that came up was the possibility of measuring the shift due to the centripetal accel eration in a high-speed rotor or cen tri fuge . One day after lunch six of us — Juergen Heberle, Carol Little john, Gil Perlow, Dick Preston, Dieter Vincent and myself — got together and decided to give it a try. We received the immediate and enthusiastic support of our director Mort Hamermesh (who also made i nvaluable contributions to our investigations) and of the Argonne Laboratory. A special “red shift” account was set up and all the needed facilities of the Laboratory were put at our di sposal