A particle beam guiding system (1a, 1b, 1c) for receiving an incoming particle beam (6a, 6b, 6c) along an incoming trajectory and controlling an exit energy level and an exit trajectory of the particle beam (6a, 6b, 6c), wherein the particle beam guiding system (1a, 1b, 1c) comprises: - a first beam guide comprising first and second guiding dipoles (26a, 26b), each comprising two magnets for creating magnetic fields for deflecting the particle beam (6a, 6b, 6c) from the incoming trajectory into an intermediate trajectory, wherein the first dipole of the first beam guide is arranged to deflect the particle beam (6a, 6b, 6c) in a first plane, and the second dipole of the first beam guide is arranged to deflect the particle beam (6a, 6b, 6c) in a second plane which is orthogonal to the first plane; - a second beam guide positioned downstream of the first beam guide, comprising first and second guiding dipoles (28a, 28b), each comprising two magnets for creating magnetic fields for deflecting the particle beam (6a, 6b, 6c) from the intermediate trajectory into the exit trajectory, wherein the first dipole of the second beam guide is arranged to deflect the particle beam (6a, 6b, 6c) in a third plane and the second dipole of the second beam guide is arranged to deflect the particle beam (6a, 6b, 6c) in a fourth plane which is orthogonal to the third plane; and - a beam trajectory monitoring and control unit positioned downstream of the second beam guide and arranged for controlling the intended exit trajectory, wherein the beam trajectory monitoring and control unit comprises first and second beam trajectory control disks (30a, 30b) of a particle beam attenuating material, each being individually movable in individual, parallel planes which are orthogonal to the incoming trajectory, and each displaying an opening (31a, 31b), the alignment of which openings (31a, 31b) defines the intended exit trajectory; characterised by further comprising: an attenuator for adjusting the energy level of the particle beam (6a, 6b, 6c); wherein the first beam guide is positioned downstream of the attenuator. - a first beam guide comprising first and second guiding dipoles (26a, 26b), each comprising two magnets for creating magnetic fields for deflecting the particle beam (6a, 6b, 6c) from the incoming trajectory into an intermediate trajectory, wherein the first dipole of the first beam guide is arranged to deflect the particle beam (6a, 6b, 6c) in a first plane, and the second dipole of the first beam guide is arranged to deflect the particle beam (6a, 6b, 6c) in a second plane which is orthogonal to the first plane; - a second beam guide positioned downstream of the first beam guide, comprising first and second guiding dipoles (28a, 28b), each comprising two magnets for creating magnetic fields for deflecting the particle beam (6a, 6b, 6c) from the intermediate trajectory into the exit trajectory, wherein the first dipole of the second beam guide is arranged to deflect the particle beam (6a, 6b, 6c) in a third plane and the second dipole of the second beam guide is arranged to deflect the particle beam (6a, 6b, 6c) in a fourth plane which is orthogonal to the third plane; and - a beam trajectory monitoring and control unit positioned downstream of the second beam guide and arranged for controlling the intended exit trajectory, wherein the beam trajectory monitoring and control unit comprises first and second beam trajectory control disks (30a, 30b) of a particle beam attenuating material, each being individually movable in individual, parallel planes which are orthogonal to the incoming trajectory, and each displaying an opening (31a, 31b), the alignment of which openings (31a, 31b) defines the intended exit trajectory;