What is faraday cup?

A Faraday cup is a device used in physics and chemistry to measure the intensity of a beam of charged particles, such as ions or electrons. It consists of a metal cup that is negatively charged, causing the particles in the beam to be attracted to it. As the particles strike the cup, they transfer their charge to it, which can then be measured as a current.

Faraday cups are commonly used in mass spectrometers to measure the abundance of ions in a sample and to determine their mass-to-charge ratio. They are also used in particle accelerators to monitor the intensity of particle beams.

Faraday cups are named after the English scientist Michael Faraday, who made important contributions to the study of electromagnetism in the 19th century.