= Lawrence-Livingston cyclotron experiment
{c}
<Ernest Orlando Lawrence> and <Milton Stanley Livingston> reported repeated <ion> acceleration in 1932. Their evacuated brass chamber used one driven hollow <cyclotron dee>; the grounded box and slotted divider supplied the other electrode. Filament <Electrons> ionized <hydrogen> near the gap. A perpendicular <magnetic field> bent the <ions>; a high-frequency <oscillator> drove the gap. Deflecting plates and slits selected particles for a <Faraday cup>, read by an <electrometer>.<The Production of High Speed Light Ions Without the Use of High Voltages by Ernest Orlando Lawrence and Milton Stanley Livingston>[Lawrence and Livingston, 1932, pp. 25–28, Figs. 2–4: actual accelerating electrode, source, collector and oscillator]{ref}
Scanning the <magnetic field> produced narrow <resonance> peaks. The optimum deflecting voltage tracked the <kinetic energy> predicted from field and orbit <radius>, supporting the reported $1.22\,\mathrm{MeV}$ <protons>. Source width and slit geometry limited this check; it was not a direct <energy> measurement of every particle.<The Production of High Speed Light Ions Without the Use of High Voltages by Ernest Orlando Lawrence and Milton Stanley Livingston>[pp. 31–33, Figs. 7–9: resonance scans, field and wavelength measurements, deflection-voltage energy check and geometric uncertainty; p. 19: maximum reported proton energy]{ref}
This combination distinguishes producing a circulating <electric current> from establishing its <kinetic energy>. The <electrometer> measures collected <electric charge> per unit time; it cannot by itself tell whether the collected particles are fast. The separate deflection selection supplies a speed-dependent test. Agreement of two consequences of the model, the <cyclotron resonance condition> and the <cyclotron energy and orbit radius> relation, makes the inference stronger than either a current signal or a predicted orbit alone.
<Milton Stanley Livingston> built the early <cyclotrons> with <Ernest Orlando Lawrence>; the 1939 <Nobel Prize in Physics> went to <Ernest Orlando Lawrence>. His lecture, The evolution of the cyclotron, was delivered on 11 December 1951.<More Timelines by Lawrence Livermore National Laboratory>[Ernest Lawrence entry: 1939 prize and delayed lecture on 11 December 1951]{ref}<M. Stanley Livingston by Fermilab>[M. Stanley Livingston: co-inventor of the cyclotron and early Berkeley work]{ref}
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