Appliance and method for tempering a plurality of process items by absorption of electromagnetic radiation generated by plural sources of the radiation

An appliance for tempering a plurality of process items in a certain gas atmosphere by acceptance of a quantity of energy by a process item by means of absorption of a certain electromagnetic radiation and by acceptance of at least a further quantity of energy by at least one further process item by means of absorption of at least a further certain electromagnetic radiation, wherein the appliance comprises:

• a first tempering unit and at least one further tempering unit arranged parallel to each other to form a stack extending in a stack direction between a first termination of the stack and a second termination of the stack,
• wherein each said tempering unit includes an energy source for generating the electromagnetic radiation and, during tempering, a process item arranged between the energy source of the first tempering unit and the energy source of the further tempering unit in the stack direction, and
• wherein the second termination of the stack is formed by an energy source, and, during tempering, a further process item arranged between the energy source of the tempering unit adjacent to the second termination and the energy source of the second termination.