Applications of the fractional calculus to study the physical theory of ion motion in a quadrupole ion trap

2017 ◽  
Vol 23 (5) ◽  
pp. 254-271 ◽  
Author(s):  
Sarkhosh S Chaharborj ◽  
Abbas Moameni

In this article, fractional calculus has been applied to study the motion of ions in a three-dimensional radio frequency quadrupole ion trap; we have called this arrangement a fractional quadrupole ion trap. The main purpose of the article is to show that by controlling the fractional parameter of a trapped ion, one can gain a more efficient mass separation. In what follows, we will see that with decreasing the fractional parameter, we can achieve a smaller first stability region. Note that a small stability diagram will result in a good and acceptable mass separation. Various methods can be proposed to obtain a desired ion acceleration with a sufficient accuracy for good mass separation, which is similar to the one obtained by a fractional ion trap. Some of these methods are using the effects of a damping force, a magnetic field or both on the confinement of particles in the quadrupole ion trap. The first stability regions are plotted for all of the aforementioned methods, and simulation results are provided to compare them with those for the fractional case.

2000 ◽  
Vol 194 (2-3) ◽  
pp. 225-234 ◽  
Author(s):  
Carsten Weil ◽  
J.Mitchell Wells ◽  
H Wollnik ◽  
R.Graham Cooks

2003 ◽  
Vol 230 (1) ◽  
pp. 65-70 ◽  
Author(s):  
Won-Wook Lee ◽  
Soon-Ki Min ◽  
Cha-Hwan Oh ◽  
Pill-Soo Kim ◽  
Seok-Ho Song ◽  
...  

2002 ◽  
Vol 8 (3) ◽  
pp. 191-199 ◽  
Author(s):  
M. Sudakov ◽  
E. Nikolaev

Ion motion in a periodic radio frequency (RF) quadrupole electric field is analysed theoretically by the matrix method and direct trajectory calculation. General properties of the ion motion: stability condition, oscillation spectrum and secular frequency are derived analytically from the elements of the transformation matrix. Stability diagrams for ion motion in the Paul ion trap are presented for rectangular waveforms with different duty cycles (duration of pulse over period). Calculation of the secular frequencies of the ion motion in the ion trap is performed for the first time. The relation of radial and axial secular frequencies along the RF scan line was found to be practically identical in both the square waveform and harmonic voltage cases. Pulse shape distortions, due to resistive-inductive-capacitive filtering in real devices, are considered. Stability diagrams of ion motion in the ion trap with distorted voltage waveforms are calculated. Distortion of the waveform is shown to introduce minor changes in the diagram shape with respect to the diagram for an ideal square wave. Within the first stable region, distortion of the waveform does not lead to any auxiliary parametric resonances of the ion motion. Ion trapping with a pure random pulsed voltage is investigated by means of direct trajectory simulations. It is shown that, in this case, the ion motion can be conditionally stable for a considerable length of time.


1969 ◽  
Vol 56 (3) ◽  
pp. 109-112 ◽  
Author(s):  
P. H. Dawson ◽  
N. R. Whetten

Sign in / Sign up

Export Citation Format

Share Document