multipole coils for influencing particle beams have at least two coils which concentrically enclose an imaginary axis , wherein a winding made from a flexible circuit board is formed by means of conducting paths disposed thereon for each coil and the circuit boards are rolled into at least one circuit board layer . multipole coils of this kind are utilized for aberration correction in particle optics , wherein the windings of the multipole coils form windows whose width in the peripheral direction is chosen in such a fashion that no secondary interfering fields occur and whose length in the axial direction corresponds at least to its width .