Faraday cup

In a metal housing (Faraday cup) a particle filter is mounted on an insulator.

A Faraday cup is a detector that measures the current in a beam of charged (aerosol) particles.

The advantage of the Faraday cup is its robustness and the possibility to measure the ion or electron stream absolutely.

A Faraday cup is a metal (conductive) cup designed to catch charged particles in vacuum.

Thus, a measured current of one nanoamp (10 A) corresponds to about 6 billion ions striking the faraday cup each second.

- capacity of Faraday cup.

Thus the expression (4) represents the I-V characteristic of the Faraday cup.

The radius at which each mass bends is already known, and three Faraday cups are set in the right places to measure each ion beam.

Similarly, a Faraday cup can act as a collector for electrons in a vacuum (for instance from an electron beam).

Faraday cups are used e.g. in mass spectrometers being an alternative to secondary electron multipliers.

The Faraday cup electrometer is the simplest form of an electrical aerosol instrument used in aerosol studies.

The Faraday cup is named after Michael Faraday who first theorized ions around 1830.

Therefore the ion current at the ion-decelerating voltage of the Faraday cup can be calculated by integrating Eq.

The signal from enables an observer to acquire an I-V characteristic of the Faraday cup by oscilloscope.

With Herbert Bridge, Rossi designed and tested a plasma probe based on the classical Faraday cup.

A Faraday cup measures the ion current hitting a metal cup, and is sometimes used for high current secondary ion signals.

Typically, some type of electron multiplier is used, though other detectors including Faraday cups and ion-to-photon detectors are also used.

The I-V curves can be recorded by using a camera connected to computer controlled data handling or by direct measurement with a movable Faraday cup.

According to Gauss' law, the charge collected on the Faraday cup is the induced charge, that means that the filter does not need to be a conductor.

A current integrator is also used to measure the electric charge on a Faraday cup in a residual gas analyzer to measure partial pressures of gasses in a vacuum.

Faraday cups are not as sensitive as electron multiplier detectors, but are highly regarded for accuracy because of the direct relation between the measured current and number of ions.

The main reasons were that monitoring directions and intensities of diffracted beams was a difficult experimental process due to inadequate vacuum techniques and slow detection methods such as a Faraday cup.

Although the MIT Faraday cup was the first American instrument that detected the solar wind, the first direct observations of solar plasma occurred within the Soviet space program.

All of the Faraday cup elements and their assembly that interact with plasma are fabricated usually of temperature-resistant materials (often these are stainless steel and teflon or ceramic for insulators).

Explorer 10 was a cylindrical, battery-powered spacecraft instrumented with two fluxgate magnetometers and one rubidium vapor magnetometer extending from the main spacecraft body, and a Faraday cup plasma probe.