Chemical Sciences: A Manual for CSIR-UGC National Eligibility Test for Lectureship and JRF/Wien filter

A Wien filter is a device consisting of perpendicular electric and magnetic fields that can be used as a velocity filter for charged particles, for example in electron microscopes and spectrometers. It is named for Wilhelm Wien who developed it in 1898 for the study of anode rays. It can be configured as a charged particle energy analyzer, monochromator, or mass spectrometer.