Abstract: To prevent electrolytic current flow between adjacent sealing foils (6,7; 15) within a pinch seal (10, 13) at the operating temperature of the pinch seal, in operation of the lamp, the pinch seal is formed with a pinch seal section which has a thickness which is reduced with respect to the pinch seal outside of the region between the foils, for example in form of a slit or a notch or a thin quartz glass web of, at the most, 3 mm thickness. This reduced section, thus, has a resistance which is a multiple of the resistance which the pinch seal, between the foils, would have if the pinch seal would be of uniform thickness throughout its cross section; this reduced section (11, 18) starts at the outer terminal end of the pinch seal (10, 13) and extends up to at least about the ends of the foils (6, 7; 14, 15) proximate to said bulb portion.