Elimination of Radio-Frequency Noise by Identifying and Diverting Large RF Ground Currents

Journal Article · Fri Dec 23 00:00:00 EST 2011 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3665028· OSTI ID:21612530

Perkins, R J; Bellan, P M ^[1]

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1. Applied Physics, California Institute of Technology (United States)

The problem of electromagnetic interference in scientific instruments is compounded for high-power plasma experiments by the large currents and voltages as well as by the broad bandwidths of the instruments. Ground loops are known to allow stray magnetic fields to drive large ground currents that can induce spurious signals and damage electronics. Furthermore, even when a ground loop is broken, capacitive coupling can still permit the flow of radio-frequency current, resulting in high-frequency spurious signals that can overwhelm the desired signal. We present the effects of RF ground loops on the output of vacuum photodiodes used in the Caltech Solar Loop Experiment and demonstrate the elimination of the spurious signals by diverting the ground currents away from the most vulnerable point of the signal line. Techniques for identifying the RF ground loops are also discussed. These techniques should be valuable in many high-power systems where interference from spurious coupling is an issue.

• OSTI ID: 21612530
• Journal Information: AIP Conference Proceedings, Vol. 1406, Issue 1; Conference: 9. topical conference on radio frequency power in plasmas, Newport (United States), 1-3 Jun 2011; Other Information: DOI: 10.1063/1.3665028; (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
COUPLING
DIVERTORS
ELECTRIC CURRENTS
ELECTRIC POTENTIAL
INDUCTANCE
INTERFERENCE
MAGNETIC FIELDS
NOISE
PHOTODIODES
PLASMA
PLASMA PRODUCTION
POWER SYSTEMS
RADIOWAVE RADIATION
RF SYSTEMS
SIGNALS
WAVE PROPAGATION
CURRENTS
ELECTRICAL PROPERTIES
ELECTROMAGNETIC RADIATION
ENERGY SYSTEMS
PHYSICAL PROPERTIES
RADIATIONS
SEMICONDUCTOR DEVICES
SEMICONDUCTOR DIODES