Abstract: Radiation therapy delivery system, including X-ray source, magnetic body rotation fixation node and/or mechanical body rotation fixation node; filter unit with a plurality of filters and a plug that circle a cylindrical element; drive unit for rotating filter unit; collimation elements in a collimation unit body, that includes collimation element fixation device and collimation photoelectric identification system; and processor controlling the filter unit to adjust X-ray filtration characteristics. The filter unit includes filter photoelectric identification system, controller, and photoelectric sensors. The cylindrical element includes slits located on rings that run along outer surface. Photoelectric sensors are triggered by a light beam that passes through the slits to identify/position filters.