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The first muon spin rotation experiment

The February 15, 1957 issue of Physical Review Letters shows the first muon precession curve resulting from the stopping of `85 MeV' muons in graphite, and the resulting counting rate in a gate of fixed delay, duration, and orientation, as a function of an applied vertical magnetic field. The p...

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Autor principal: Garwin, Richard L
Lenguaje:eng
Publicado: 2003
Materias:
Acceso en línea:http://cds.cern.ch/record/624996
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author Garwin, Richard L
author_facet Garwin, Richard L
author_sort Garwin, Richard L
collection CERN
description The February 15, 1957 issue of Physical Review Letters shows the first muon precession curve resulting from the stopping of `85 MeV' muons in graphite, and the resulting counting rate in a gate of fixed delay, duration, and orientation, as a function of an applied vertical magnetic field. The purpose of the four-day experiment was to test the conservation of parity in the weak interactions. It involved the sudden recognition that existing muon beams would be polarized if parity were not conserved, together with the appreciation that the angular distribution of decay electrons from the population of stopped muons could be observed (much more reliably and sensitively) by the variation with time or current of the detections in a fixed counter telescope than by the measurement of the decay asymmetry of nominally fixed muon spins. This retrospective paper explains the context, the state of the art at the time, and what we expected as a consequence of this experiment. We went on to study more accurately the magnetic moment of the muon, its gyromagnetic ratio-g-and only to a small extent used mu SR to investigate the environment of the muon in matter. Much of the paper treats the instrumentation of the time - especially that adopted in the early 1950s. The essential tools of nanosecond-range coincidence circuits and adiabatic light pipes for scintillation counters are discussed. The paper closes with some later work of the author and his colleagues - measurements of the magnetic moment of the muon and especially the CERN measurement of muon g-2. An expanded version of this presentation is posted at http:// www.fas.org/RLG. (7 refs).
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spelling cern-6249962019-09-30T06:29:59Zhttp://cds.cern.ch/record/624996engGarwin, Richard LThe first muon spin rotation experimentScience in GeneralThe February 15, 1957 issue of Physical Review Letters shows the first muon precession curve resulting from the stopping of `85 MeV' muons in graphite, and the resulting counting rate in a gate of fixed delay, duration, and orientation, as a function of an applied vertical magnetic field. The purpose of the four-day experiment was to test the conservation of parity in the weak interactions. It involved the sudden recognition that existing muon beams would be polarized if parity were not conserved, together with the appreciation that the angular distribution of decay electrons from the population of stopped muons could be observed (much more reliably and sensitively) by the variation with time or current of the detections in a fixed counter telescope than by the measurement of the decay asymmetry of nominally fixed muon spins. This retrospective paper explains the context, the state of the art at the time, and what we expected as a consequence of this experiment. We went on to study more accurately the magnetic moment of the muon, its gyromagnetic ratio-g-and only to a small extent used mu SR to investigate the environment of the muon in matter. Much of the paper treats the instrumentation of the time - especially that adopted in the early 1950s. The essential tools of nanosecond-range coincidence circuits and adiabatic light pipes for scintillation counters are discussed. The paper closes with some later work of the author and his colleagues - measurements of the magnetic moment of the muon and especially the CERN measurement of muon g-2. An expanded version of this presentation is posted at http:// www.fas.org/RLG. (7 refs).oai:cds.cern.ch:6249962003
spellingShingle Science in General
Garwin, Richard L
The first muon spin rotation experiment
title The first muon spin rotation experiment
title_full The first muon spin rotation experiment
title_fullStr The first muon spin rotation experiment
title_full_unstemmed The first muon spin rotation experiment
title_short The first muon spin rotation experiment
title_sort first muon spin rotation experiment
topic Science in General
url http://cds.cern.ch/record/624996
work_keys_str_mv AT garwinrichardl thefirstmuonspinrotationexperiment
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