Patent Number: 
Section: claims

1. A machine ( 1 ) for producing energy by nuclear fusion reactions, characterized by comprising a reaction chamber ( 2 ); a target ( 5 ) housed inside said reaction chamber ( 2 ); a positive deuterium ion source ( 3 ) communicating with said reaction chamber ( 2 ); and a pumping assembly ( 4 ) communicating with said reaction chamber ( 2 ) to maintain a vacuum inside the reaction chamber ( 2 ); said target ( 5 ) comprising an active element ( 31 ) made of a material having a crystal lattice and deuterium atoms in its crystal lattice; and said positive deuterium ion source ( 3 ) feeding a flux of positive deuterium ions into the reaction chamber ( 2 ), so that said flux of positive deuterium ions strikes said active element ( 31 ) of the target ( 5 ) to produce nuclear fusion reactions between the incident positive deuterium ions and the atoms constituting the target ( 5 ) itself, said target ( 5 ) comprising an outer casing ( 30 ), which is substantially cup-shaped with a cavity ( 30 a ) facing said focusing device ( 13 ); said active element ( 31 ) being housed inside said outer casing ( 30 ) and being substantially cup-shaped with a cavity ( 31 a ) facing a focusing device ( 13 ); said active element ( 31 ) being struck by a concentrated beam of positive deuterium ions. 2. A machine as claimed in  claim 1 , characterized in that said reaction chamber ( 2 ) comprises accelerating means ( 10 ) for conveying said flux of positive deuterium ions against said target ( 5 ) and accelerating the positive deuterium ions. claim 1 3. A machine as claimed in  claim 2 , characterized in that said accelerating means ( 10 ) comprise at least two electrodes ( 5 ,  12 ) housed inside the reaction chamber ( 2 ); and an electric energy source ( 11 ) for maintaining an in any way variable difference in electric potential between the two electrodes ( 5 ,  12 ); one of said two electrodes ( 5 ,  12 ) being defined by said target ( 5 ). claim 2 4. A machine as claimed in  claim 1  characterized in that said reaction chamber ( 2 ) comprises a focusing device ( 13 ) through which said flux of positive deuterium ions travels prior to striking said target ( 5 ); said focusing device ( 13 ) focusing said flux of positive deuterium ions to form a concentrated beam of positive deuterium ions. claim 1 5. A machine as claimed in  claim 1 , characterized in that said outer casing ( 30 ) is made of metal material. claim 1 6. A machine as claimed in  claim 5 , characterized in that said outer casing ( 30 ) is defined by a stack of alternating washers ( 32 ) made of different metal materials and held together by gripping means. claim 5 7. A machine as claimed in  claim 1 , characterized in that said active element ( 31 ) is defined by an aggregate comprising metal salts. claim 1 8. A machine as claimed in  claim 7 , characterized in that some of the metal salts belong to the class of sulfates comprising ferrous sulfate, nickel sulfate, titanium sulfate and potassium sulfate. claim 7 9. A machine as claimed in  claim 7 , characterized in that the metal salts are selected from copper sulfate and lithium sulfate; said sulfate being hydrated with heavy water. claim 7 10. A machine as claimed in  claim 1 , characterized in that said material of said active element ( 31 ) is capable, when stricken by a deuterium ion flux, of absorbing positive deuterium ions and starting an endothermic reaction with said positive deuterium ions. claim 1 11. A machine as claimed in  claim 1 , characterized in that said positive deuterium ion source ( 3 ) comprises a tank ( 15 ) containing deuterium atoms in gaseous form for supply to said reaction chamber ( 2 ); and an ionizing unit ( 16 ) interposed between said tank ( 15 ) and said reaction chamber ( 2 ) to so ionize the deuterium atoms as to supply said reaction chamber ( 2 ) with a flux of positive deuterium ions. claim 1