Kinetic Energy of Trapped Ions Cooled by Buffer Gas

The average kinetic energy of 40Ca+ ions is measured by the method of evaporating ions in an rf ion trap. The kinetic energy of the ion 40Ca+ varies from 0.5 eV to 0.2 eV with changing buffer gas pressure from 10-7 mbar to 10-5 mbar. The Brownian motion model is also introduced to calculate the average kinetic energy of the trapped ions.