A charged particle trap for trapping of a plurality of charged particles. The trap includes first and second electrode mirrors (2,3) having a common optical axis (4), the mirrors being arranged in alignment at two extremities thereof. The mirrors are capable, when voltage is applied thereto, of creating respective electric fields defined by key field parameters. The electric fields are configured to reflect charged particles causing their oscillation between the mirrors. The plurality of charged particles is introduced into the trap, along the optical axis, as a beam (10) having pre-determined key beam parameters. The key field parameters for at least one of the mirrors are chosen such as to induce bunching among charged particles in the beam.