Patent Number: 047605901
Section: claims

1. In a multioperation accelerator for radiotherapy of the particle beam type comprising a target bombarded by said particle beam for generating a photon beam, the HF supply power of said accelerator is fixed once and for all at a predetermined level and it comprises several switchable targets at the output of said accelerator, allowing a predetermined number of target-filter combinations to be selectively moved by mechanical switch means into the particle beam to produce photon beams with different chosen characteristics with the penetration curve of the photon beams being modified by the distribution of the energy of the photons below an upper limit without modifying the upper limit, which are varied only with the selection of the target and filter, said targets and filters being stationary during the operation of the device. 2. The multioperation accelerator as claimed in claim 1, further comprising a mobile support containing several targets each having a main axis of symmetry, the path of said support passing in front of the output of said accelerator and positioning means being provided for aligning any target axis with the main axis of the accelerator. 3. The multioperation accelerator as claimed in claim 1, comprising a single fixed target disposed at the output of said accelerator and centered on its main axis, a mobile support containing several filters each having a main axis of symmetry, the path of said support passing in front of said target and in the vicinity thereof and positioning means being provided for aligning the axis of any filter with the main axis of the accelerator. 4. The multioperation accelerator as claimed in claim 1, comprising a mobile support containing several targets and several filters fixed respectively in twos facing each other so that a main axis of symmetry of each target merges with a main axis of symmetry of the corresponding filter, positioning means being provided for aligning any of these axes with the main axis of the accelerator. 5. The multioperation accelerator as claimed in claim 1, comprising a mobile support containing several targets each having a main axis of symmetry and a mobile support containing several filters each having a main axis of symmetry, positioning means being provided for aligning the axis of symmetry of any filter and the axis of symmetry of any target with the main axis of the accelerator. 6. The accelerator as claimed in one of claims 2 to 5, wherein said support comprises cavities each housing a filter and/or a target. 7. The accelerator as claimed in one of claims 2 to 5, wherein said support made essentielly form lead and comprises cavities each housing a filter and/or a target. 8. The accelerator as claimed in claim 2, wherein each said mobile support or supports is in the form of a drawar with rectilinear movement. 9. The accelerator as claimed in claim 1, wherein each of said mobile supports is in the form of a rotary turret. 10. The accelerator as claimed in claim 2, wherein each of said mobile supports is in the general form of a cross with two slides having two perpendicular rectilinear directions of movement. 11. The accelerator as claimed in claim 1, wherein the filters are made from a material chosen from the group consisting of tungsten, lead, copper, titanium, stainless steel and graphite. 12. The accelerator as claimed in claim 1, wherein at least one filter has a pyramidal or conical shape, known per se. 13. The accelerator as claimed in one of claims 2, 4 or 5, wherein said targets are made of different materials. 14. The accelerator as claimed in one of claims 3 4 or 5, wherein said filters are made of different materials.