Reflectron nonlinear

Alternatively, the Shimadzu Corporation (Manchester, JK)AXIMA TOF tandem uses a curved field reflectron (Figure 10.10c). This reflectron uses a nonlinear field defined by potentials on the lens elements that approximates the arc of a circle F = V + x, where V is the voltage, x is the distance from the reflectron entrance, and is a constant. Because the reflectron can accommodate a wide range of product ion energies, the ions are not decelerated or reaccelerated. Collision energies can then be as high as 20keV. 

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