An x-ray source for generating x-rays with at least one narrow energy band, comprising: an enclosing vessel; a first contact arranged with a first contact surface in said enclosing vessel; a second contact arranged with a second contact surface in said enclosing vessel; and an actuator assembly operatively connected to at least one of said first and second contacts, wherein said actuator assembly is structured to cause said first contact surface and said second contact surface to repeatedly come into contact, and separate after making contact, while in operation, characterized in that said first contact surface is a surface of a first triboelectric material and the first triboelectric material is a polymer and said second contact surface is a surface of a second triboelectric material comprising an epoxide, said surface of said first triboelectric material having a negative triboelectric potential relative to said surface of said second triboelectric material, wherein said second contact comprises said second triboelectric material and an additional material comprising an atomic element in its composition that has an excited quantum energy state that can be excited by electrons traveling from said first contact surface to said second contact surface, wherein said additional material comprising said atomic element is a metal wherein said epoxide is loaded with said metal wherein said atomic element emits x-rays having an energy within said at least one narrow energy band upon transition from said excited state into a lower energy state, and wherein said enclosing vessel is structured to provide control of an atmospheric environment to which said first and second contact surfaces are exposed. an enclosing vessel; a first contact arranged with a first contact surface in said enclosing vessel; a second contact arranged with a second contact surface in said enclosing vessel; and an actuator assembly operatively connected to at least one of said first and second contacts, wherein said actuator assembly is structured to cause said first contact surface and said second contact surface to repeatedly come into contact, and separate after making contact, while in operation, characterized in that said first contact surface is a surface of a first triboelectric material and the first triboelectric material is a polymer and said second contact surface is a surface of a second triboelectric material comprising an epoxide, said surface of said first triboelectric material having a negative triboelectric potential relative to said surface of said second triboelectric material, wherein said second contact comprises said second triboelectric material and an additional material comprising an atomic element in its composition that has an excited quantum energy state that can be excited by electrons traveling from said first contact surface to said second contact surface, wherein said additional material comprising said atomic element is a metal wherein said epoxide is loaded with said metal wherein said atomic element emits x-rays having an energy within said at least one narrow energy band upon transition from said excited state into a lower energy state, and wherein said enclosing vessel is structured to provide control of an atmospheric environment to which said first and second contact surfaces are exposed.