R. Alheit et al., OBSERVATION OF INSTABILITIES IN A PAUL TRAP WITH HIGHER-ORDER ANHARMONICITIES, Applied physics. B, Lasers and optics, 61(3), 1995, pp. 277-283
Systematic measurements of the relative ion number stored in a Paul tr
ap within the stability diagram given by the solution of the equation
of motion reveal many lines, where only few or no ions can be confined
. The observations can be explained by the presence of perturbations f
rom higher-order components in the trapping potential, which is a quad
rupole potential in the ideal case. The resonances follow the equation
(n(r)/2) beta(r) + (n(z)/2) beta(z) = 1, n(r) + n(z) = N, where 2N is
the order of the perturbation, n(r), n(z) are integer and beta(r), be
ta(z) are stability parameters of the trap. The experiments were perfo
rmed on H+ and H-2(+) ions, which are detected after a storage time of
0.3 s by ejection from the trap.