Motion of Ions in Electric and Magnetic Fields

All m/z analyzers rely on application of electric and/or magnetic fields to separate ions according to their m z 

Michael Faraday (1791-1867) was a British chemist and physicist (he considered himself a natural philosopher) who made enormous contributions to electromagnetism and electrochemistry. He is widely regarded as the greatest experimentalist in the history of science. It was largely due to his efforts that electricity became viable for use in technology. The SI unit of capacitance (the farad) is named after him, as is the Faraday Constant (the charge on a mole of electrons, about 96485 coulombs). He made many discoveries in chemistry, including benzene, and invented a system of oxidation numbers of the elements. 

Faraday was bom in south London to a poor family his father was a Yorkshire blacksmith who suffered ill-health throughout his life. In the rigidly class-conscious England of that day, a poor lad like Faraday had no chance of much of a formal education and indeed in his early years he suffered considerably from intolerance of this kind, particularly from the wife of the scientist Humphrey Davy who employed Faraday as laboratory assistant. He appears to have borne no rancor as a result he was a devout member and elder of the small Sandemanian denomination, an offshoot of the Church of Scotland. During his lifetime, Faraday rejected a knighthood and twice refused to become President of the Royal Society. There is a plaque in his memory in Westminster Abbey near Newton s tomb, but he refused to be buried there and is interred in the Sandemanian plot in Highgate Cemetery in London. 

In very general terms, a field (e.g. gravitational, electric or magnetic) at a point in space describes the force 

Various types of electric field are used in different mass analyzers. From this perspective the simplest example is provided by the constant field (DC) strengths used to accelerate ions, e.g. out of an ion source into an analyzer, or from an intermediate component into the flight tube of a time of flight analyzer etc. More elaborate fields whose strength is varied in time at frequencies in the range of a few MHz (within the radiofrequency (RF) range) are used in linear quadrupoles and ion traps. However, the same principles of physics are exploited in aU cases, and the following section is an introduction to these principles. 

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