Asymmetric hardware support for a special class of threads is provided. In a method for delivering a particle beam to a patient through a gantry, a particle beam is guided by a plurality of variable field magnets sequentially arranged along a beam tube of the gantry and the beam is alternately focused and defocused with alternately arranged focusing and defocusing variable field magnets. The first interval average value providing an average of the instantaneous value for a first predetermined time length, and the second interval average value providing an average of the instantaneous value for a second predetermined time length are determined.