Vacuum ultraviolet light source utilizing rare gas scintillation amplification sustained by photon positive feedback
OwnerElena Aprile, Danli Cheninventors
Life of this patent
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Abstract
A source of light in the vacuum ultraviolet (VUV) spectral region includes a reflective UV-sensitive photocathode supported in spaced parallel relationship with a mesh electrode within a rare gas at low pressure. A high positive potential applied to the mesh electrode creates an electric field which causes drifting of free electrons occurring between the electrodes and producing continuous VUV light output by electric field-driven scintillation amplification sustained by positive photon feedback mediated by photoemission from the photocathode. In one embodiment the lamp emits a narrow-band continuum peaked at 175 nm.
Claims19
A source of light in the vacuum ultraviolet (VUV) spectral region, comprising:
- a vessel containing a rare gas, said vessel having an output window which is substantially transparent to light in the VUV spectral region;
- first and second electrodes supported within said vessel in parallel spaced relationship, wherein said first electrode is an ultraviolet-sensitive photocathode and said second electrode is a mesh electrode;
- and
- means for applying to said mesh electrode a positive potential relative to said photocathode sufficiently high to create an electric field between said first and second electrodes for causing drifting of free electrons occurring between said electrodes and producing continuous VUV light output by electric field-driven scintillation amplification sustained by positive photon feedback mediated by photoemission from said photocathode.
A light source for producing light in the vacuum ultraviolet (VUV) spectral region by electric field-driven scintillation amplification, sustained by positive photon feedback mediated by photoemission from the photocathode comprising:
- a vessel having an output window substantially transparent to VUV light and containing a rare gas at low pressure;
- a planar mesh electrode supported within said vessel adjacent said output window;
- an ultraviolet sensitive photocathode spaced from and facing said planar mesh electrode;
- and
- means for connecting a source of voltage between said photocathode and said mesh electrode to thereby create said electric field.
Method for producing light in the vacuum ultraviolet (VUV) spectral region comprising the steps of:
- providing a lamp having a reflective ultraviolet- sensitive photocathode facing and spaced from a mesh electrode in a low pressure rare gas medium;
- and
- applying to said mesh electrode a potential which is positive relative to a potential applied to said photocathode sufficiently high to create an electric field between said photocathode and said mesh electrode for drifting free electrons occurring in the space therebetween and producing a continuous VUV light output through said mesh electrode by electric field-driven scintillation amplification sustained by positive photon feedback mediated by photoemission from said photocathode.
Dependencies are inferred from the claim text.