The application describes an apparatus and a method for the thermal treatment of substrates, in particular thin film substrates for photovoltaic applications. Between the MG and the IPM, there is provided a cooler through which a coolant liquid flows, provided in an inclined manner to form contact with the top face of the IPM. Each pane contains a scaled virtual desktop having dimensions that are proportionally less than the dimensions of a corresponding full-size virtual desktop. If the first switching field is substantially higher than the second switching field, the first MTJ may be a reference element for the second MTJ. The outer edge includes a linear portion extending from the second tip to a curvilinear portion, which defines a fin.