Amplitude Stabilizer for Magnetic Field Modulators
| Autor: | David Shaltiel, Yosef Alon |
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| Rok vydání: | 1968 |
| Předmět: | |
| Zdroj: | Review of Scientific Instruments. 39:1623-1626 |
| ISSN: | 1089-7623 0034-6748 |
| DOI: | 10.1063/1.1683187 |
| Popis: | It is desirable to stabilize the amplitude and phase of magnetic field modulation applied to dc swept laboratory magnets for better approximation of true line shape, when large sweeps affect modulation coil impedance along with magnet yoke permeability. A stabilizing circuit is proposed in the form of a gain‐controlled preamplifier, the control signal being derived from the integrated output of a pickup coil, which is also used as reference for synchronous detection. This instrument adapts to existing power modulators to provide a unity cosine reference signal and to stabilize modulation amplitude to 1% over 3 decades of dynamic range, over a band of 25 cps to 150 kc. The use of the instrument in ESR spectrometry is demonstrated; in a specific case of measuring the g shift of magnetic impurities in metals, results obtained with and without the use of the stabilizer are compared. Detecting a broad line of 1380 G at 16.5 kG center field with standard equipment produces an apparent shift of the line center o... |
| Databáze: | OpenAIRE |
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