A flat panel display includes a plurality of pixel anode electrodes arranged in a display area. A required number of said unit operations is combined, selected and optimized individually for each radioisotope production scheme. The inverse of X may be obtained by multiplying x\u22121=\u22121 by xpm. Therefore, the present invention can allow current for measuring the resistance sequentially along the first line contact region and the second line contact region to measure the line contact resistance in which the contact resistance in every source portion is considered.