FIELD: medicine.SUBSTANCE: invention relates to medicine. Element for beam formation is intended for use in neutron capture therapy. Neutron capture therapy involves use of an accelerating tube designed to accelerate a proton beam； wherein beam forming element comprises beam inlet, target located in accelerating tube, retarder adjacent to said target, a reflector surrounding said retarder from the outside, a thermal neutron absorber adjacent to said retarder, a radiation shield installed inside said beam forming element, and an output for the beam. Target and the proton beam coming from said beam input cause a nuclear reaction to produce neutrons. Neutrons form neutron beams； said retarder decelerates neutrons extracted from said target to the epithermal neutron energy range. Reflector reflects the deflected neutrons back to the said retarder to increase the epithermal neutron beam intensity. Thermal neutron absorber is designed to absorb thermal neutrons in order to prevent the effect of excessive doses on surface normal tissues during therapy. Radiation protection shield is designed to prevent leakage of neutrons and photons in order to reduce dose for normal tissues in non-irradiated zones. Beam forming element is also equipped with cooling device, wherein said cooling device comprises a first cooling portion for cooling the target, as well as a second cooling portion and a third cooling portion, each of which passes parallel to the direction of the axial line of the accelerating tube and is made in communication with the first cooling portion, wherein the first cooling portion is in contact with the flat surface of the target, cooling medium enters the first cooling part into the first cooling part, and the cooling medium from the first cooling part comes out along the third cooling part.EFFECT: technical result of the declared invention consists in increasing the effectiveness of treating malignant tumours.10 cl, 2 tbl, 4 dwgИзобретение относится к области меди
