Abstract: An atomic spectral lamp of the type comprising a predominantly glass envelope in which are disposed spaced electrodes for producing an electrical discharge on application of a suitable potential difference thereto and a substance which, on being heated will yield a vapor of an element capable of emitting the resonance line or lines which characterize the lamp. In normal operation of the lamp, there exists between the anode and the cathode a temperature gradient effective to ensure that the vapor pressure of the elemental vapor adjacent the cathode is small relative to the vapor pressure of the elemental vapor in the vicinity of said substance. In another aspect, heating means is provided for heating the substance independently of the discharge to yield the elemental vapor within the envelope.

Abstract: A high intensity atomic spectral lamp having a first set of electrodes including a primary cathode consisting of or comprising a selected element adapted to produce a primary electric discharge which gives rise to an atomic vapor of said element by cathodic sputtering from the primary cathode; a second set of electrodes adapted to produce a secondary electric discharge which passes through the said atomic vapor, to excite the atoms in the vapor to emit radiation characteristic of said element; a window to allow the passage of said radiation out of the lamp, said window being placed in front of the operative surface of the primary cathode; means to pass a stream of inert gas through the lamp close to and across the operative surface of the primary cathode and between the primary cathode and the window in such manner as to sweep away from the vicinity of the primary cathode surface atomic species formed by said primary discharge.