A new impulsional potential for a Paul ion trap

Abstract

The dynamical behavior of an ion confined in a Paul ion trap supplied with a new periodic impulsional potential in the form as f( t) = V((cos Ωt ⌊ 1 + k cos 2 Ωt ⌋)/(1 − k)); 0 ≤ k < 1 (⌊· ⌋ means floor function) is considered and eventually compared to the classical sinusoidal case, k = 0. The new potential presents large zero potential temporal zones and the numerical integration of the Mathieu equation with the help of the fifth-order Runge–Kutta method showed some reduction in the stability diagrams, but for the same β, the properties of the confined ions stayed the same. Also, for given operational parameters such as Ω = 2 Π × 1.05 × 10 6 rad s −1, z 0 = 0.783 cm, and rf only mode U = 0 ( a z = 0), the potential difference V rf values for m = 1 and m = 2 ions is found to be V rf = 11 V for k = 0 and V rf = 130 V for k = 0.9. A larger separation, about 12 times for the impusional voltage compared to the classical sinusoidal which in term means a better mass separations and detection.