[me261290]

I'm doing about mass spectrometers and need to know how passing through the accelerating field makes the atoms speed up if anyone can help it would be much appreciated 

[Biopyro]

As the atom passes into the spectrometer, it is ionised by electrons from the electron gun. These "knock off" an electron giving it a positive charge. The ion is now attracted to the negative accelerator plates. once it is past these it's velocity is enough to escape the pull of the plates and it continues through the spectrometer

[DevaDevil]

the accelerator plates gradually decrease in potential, with the final one being at 0 V, hence at the final plate the ion will escape the pull of the plates easily.

a nice page explaining in a simple way how a MS works