Patent Number: 
Section: claims

1. An electron exit window foil for use with a high performance electron beam generator operating in a corrosive environment, the electron exit window foil comprising a sandwich structure havinga film of Ti,a first layer of a material having a higher thermal conductivity than Ti,a flexible second layer of a material being able to protect said film from said corrosive environment, wherein the second layer is facing the corrosive environment, andat least one adhesive barrier coating between the Ti film and the first layer and/or the second layer,wherein said at least one adhesive barrier coating is a layer of Al2O or ZrO2. 2. The electron exit window foil according to claim 1, wherein the first layer is arranged between the film and the second layer. 3. The electron exit window foil according to claim 1, wherein the Ti film is arranged between the first layer and the second layer. 4. The electron exit window foil according to claim 1, wherein the material of the first layer has a ratio between thermal conductivity and density higher than that of Ti. 5. The electron exit window foil according to claim 1, wherein the first layer is selected from the group consisting of Al, Cu, Ag, Au, and Mo. 6. The electron exit window foil according to claim 1, wherein the second layer is selected from the group consisting of Al2O3, Zr, Ta, and Nb. 7. The electron exit window foil according to claim 1, wherein said at least one adhesive barrier coating is between the first layer and the second layer, and wherein said layers are arranged on the same side of the Ti film. 8. The electron exit window foil according to claim 1, wherein said at least one adhesive barrier coating has a thickness between 1 and 150 nm. 9. An electron beam generator configured to operate in a corrosive environment, comprisinga body housing and protecting an assembly generating and shaping the electron beam, anda support carrying components relating to the output of the electron beam, said support comprising an electron exit window foil according to claim 1. 10. A method for providing an electron exit window foil for use with a high performance electron beam generator operating in a corrosive environment, said method comprising:providing a film of Ti,providing a first layer of a material having a higher thermal conductivity than Ti onto a first side of said film,providing a flexible second layer of a material being able to protect said film from said corrosive environment, wherein the second layer is facing the corrosive environment, andproviding at least one adhesive barrier coating between the Ti film and the first layer and/or the second layer,wherein said at least one adhesive barrier coating is a layer of Al2O or ZrO2. 11. The method of claim 10, wherein the providing of the flexible second layer comprises arranging said flexible second layer onto a second side of said film. 12. The method according to claim 10, wherein the providing of the flexible second layer comprises arranging said flexible second layer onto said first layer. 13. The method according to claim 10, wherein at least one of the providing of the first layer or the providing of the flexible second layer is preceded by providing an adhesive coating onto said film. 14. A method for providing a high performance electron beam device, comprising:providing a foil-frame subassembly comprising the steps of:attaching a film of Ti onto a frame, andprocessing said film by providing a first layer of a material having a higher thermal conductivity than Ti onto a first side of said film, and providing a flexible second layer of a material being able to protect said film from said corrosive environment, wherein the second layer is facing the corrosive environment andattaching said foil-frame subassembly to a tube housing of an electron beam device for sealing said electron beam device.