Deflectors

Deflectors are devices or surfaces that redirect the trajectory of a flow, beam, or wave. They work by imparting a change in momentum through contact with a boundary, by applying forces via fields, or by altering the wavefront. Deflectors are used to steer materials, protect surfaces, distribute energy, or guide signals in a range of disciplines, from mechanical engineering to optics and particle physics.

Common forms include mechanical or aerodynamic deflectors that redirect air or liquids, such as air deflectors in HVAC ducting, rain deflectors on windshields, or splash guards on machinery. Optical and laser deflectors steer light beams using mirrors, prisms, or electro-optic and acousto-optic devices. In particle accelerators and mass spectrometers, deflection is achieved with magnetic dipoles or electrostatic plates to bend charged particles along the desired path. In cathode-ray tubes and certain display technologies, deflectors control electron beams with magnetic or electrostatic fields.

Design considerations include the required deflection angle, beam quality, response time, and material or field strengths. Deflectors must withstand the forces involved, minimize unwanted scattering or aberrations, and maintain precision over operating conditions. In many applications, deflectors are part of feedback systems that adjust trajectory in real time.