An apparatus for transporting a charged particle beam is provided. The apparatus may include: means for scanning the charged particle beam on a target, a dipole magnet arranged upstream of the means for scanning, at least three quadrupole lenses arranged between the dipole magnet and the means for scanning, and means for adjusting the field strength of at least three quadrupole lenses in function of the scanning angle of the charged particle beam. The apparatus can be made at least single achromatic.
