Lancaster: American Physical Society, 1950. 1st Edition. FIRST EDITION IN ORIGINAL WRAPS of the important first detection and report of spin echoes in nuclear magnetic resonance (NMR). "In magnetic resonance, a spin echo is the refocusing of spin magnetisation by a pulse of resonant electromagnetic radiation. Modern NMR and magnetic resonance imaging make use of this effect... Echo phenomena are important features of coherent spectroscopy which have been used in fields other than magnetic resonance including laser spectroscopy and neutron scattering" (Wikipedia). In 1950, Erwin Hahn, then a graduate student, was experimenting with NMR using pulsed RF energy and observed echo signals, hereafter called 'Spin Echo' or 'Hahn Echo' signals.
According to Hahn, "the often cited nuclear spin echo effect was discovered by accident because I happened to be the first to use radio frequency pulses of the right sort to look at nuclear magnetic resonance signal transients... One day a strange signal appeared on the oscilloscope, in the absence of a pulse pedestal, so I kicked the apparatus and breathed a sigh of relief when the signal went away. A week later, the signal returned, and this time it checked out to be a real spontaneous spin echo nuclear signal from the test sample of protons in the glycerine being used. In about three weeks, I was able to predict mathematically what I suspected to be a constructive interference of precessing nuclear magnetism components by solving the Bloch nuclear induction equations.
"Here for the first time, a free precession signal in the absence of driving radiation was observed first, and predicted later. The spin echo began to yield information about the local atomic environment in terms of various amplitude and frequency memory beat effects, certainly not all understood in the beginning... Little did the early NMR resonance community realize that the analogue of spin echo hidden memory contained in excited phases of condensed matter, including plasmas, would be obtained today by use of optical laser, electric, and acoustic pulses as well" (Hahn, This Week's Citation Classic, 30, September 24, 1979). Item #414
CONDITION & DETAILS: Lancaster: American Physical Society. Physical Review, Volume 80, Number 4, November 15, 1950, pp. 580-594. Quarto (11.25 x 8.25 inches; 275 x 200mm). Original wraps with slight rubbing and scuffing around the edges; small chip at the foot of the spine. Bright and clean throughout. Very good condition.