Patent Number: 
Section: claims

1. Neutron radiation installation for treatment of different types of cancer tumors, comprising: a source of neutrons,  a first filter for reducing a radiation energy of the source of neutrons to a level for radiation treatment of cancer tumors, the radiation energy reduced by said first filter producing low energetic neutron beams with an energy of between 1 eV and 40 keV,  a radiation tube from which the neutron beams are emitted from an output towards a patient having a cancer tumor, and  a second radiation filter mounted between the first filter and the output of the radiation tube, which second filter  is a plate of metallic lithium, or another form of the element lithium, which has been enriched to about 95% in the isotope Li 6 ,  has a thickness of about 2 cm over all of the output of the radiation tube directed to the patient, and  filters off neutrons in the epithermal spectrum from the low energetic neutron beams up to an energy less than about 1 keV. 2. Neutron radiation installation according to  claim 1 , characterized in that the source of neutron beams is a nuclear reactor or an accelerator dependent source of neutrons. claim 1 3. Neutron radiation installation according to  claim 1 , characterized in that the second filter lets through beams having an energy of between 1 keV and 20 keV. claim 1 4. Neutron radiation installation according to  claim 1 , characterized in that the second filter is mounted succeeding the first filter and in advance of the radiation position zone. claim 1 5. Neutron radiation installation according to  claim 1 , characterized in that the installation is formed so that an optimum radiation effect is obtained at a distance of about 50-100 cm from the output surface of the filter. claim 1