# US 7,609,816 B2 · Renewable laser target > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,609,816 B2 - Document ID: US7609816B2 - Status: Granted - Kind: B2 - Application number: 11/751,568 - Filed: 2007-05-21 - Published: 2009-01-15 - Granted: 2009-10-27 - Earliest claimed: 2006-05-19 - Assignees: Colorado State University Research Foundation - Inventors: Jorge J. Rocca - Web page: https://patentgrep.com/patent/US7609816B2 ## CPC - H05G 2/0027: {Arrangements for controlling the supply; Arrangements for measurements} - H01S 4/00: Devices using stimulated emission of electromagnetic radiation in wave ranges other than those covered by groups H01S1/00, H01S3/00 or H01S5/00, e.g. phonon masers, X-ray lasers or gamma-ray lasers - H01S 3/06: Construction or shape of active medium - H05G: X-RAY TECHNIQUE (investigating or analysing materials by the use of X-rays G01N23/00; apparatus for X-ray photography G03B42/02; X-ray tubes H01J35/00; TV systems having X-ray input H04N5/321) - H01S: DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL ## Abstract Generation of 2 μW average output power at 13.9 nm from a table-top laser-pumped Ni-like Ag laser operating at 5 Hz repetition rate using a silver-coated helical target which is rotated and advanced such that the target surface is renewed between pulses, is described. Greater than 2×104 soft x-ray laser pulses were obtained using a single target. Similar results were obtained at 13.2 nm for Ni-like Cd using a cadmium-coated target. Uninterrupted operation of laser-pumped soft x-ray lasers at a repetition rates of about 10 Hz for periods of several hours enables the generation of pulsed, high average power soft x-rays for applications. Other embodiments of the renewable laser target are described. ## Claims ### Claim 1 A renewable, laser-pumped target for generating soft x-ray radiation, comprising in combination: a cylindrical body having an outer surface, an axis of symmetry, a first end and a second end, wherein a helical step having a rectangular cross section and a flat outer surface on which a pump-laser beam target area is defined for a chosen pump-laser beam geometry, is formed in the outer surface of said cylindrical body; and means for rotating said cylindrical body about the axis of symmetry thereof, and translating said cylindrical body along the axis of symmetry thereof such that the pump-laser beam target area is refreshed while maintaining the chosen pump-laser beam geometry. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein said means for rotating and translating said cylindrical body comprises: a screw having a chosen diameter and selected thread pitch attached to the first end of said cylindrical body along the axis of symmetry; a stationary threaded block adapted to receive said screw; a stepping motor for incrementally rotating said screw about the axis of symmetry; and means for controlling said stepping motor. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein said means for rotating and translating said cylindrical body comprises: rotation apparatus; translation apparatus upon which said rotation apparatus is mounted; and means for controlling said rotation apparatus and said translation apparatus. ### Claim 4 (depends on 1) The renewable laser target of claim 1, further comprising a coating of a selected material and having a chosen thickness formed on the outer surface of the rectangular step, whereby soft x-rays having selected wavelengths are generated. ### Claim 5 A method for generating a renewable, laser-pumped target for generating soft x-ray radiation, comprising the steps of: forming a helical step having a rectangular cross section in the outer surface of a cylindrical body on which a pump-laser beam target area is defined for a chosen pump-laser beam geometry, said cylindrical body having an axis of symmetry; incrementally rotating said cylindrical body about the axis of symmetry thereof; and advancing said cylindrical body along the axis of symmetry thereof with each incremental rotation of the cylindrical body, such that the pump-laser beam target area is refreshed while maintaining the chosen pump-laser beam geometry with each incremental rotation of the cylindrical body. ### Claim 6 (depends on 5) The method of claim 5 further comprising the step of coating the outer surface of the rectangular step with a selected material having a chosen thickness, such that selected wavelengths of soft x-radiation are generated. ### Claim 7 A renewable, laser-pumped laser target for generating soft x-ray radiation, comprising in combination: an elongated body having a polygonal cross section with flat faces, an axis of symmetry, and an outer surface on which a pump-laser beam target area is defined for a chosen pump-laser beam geometry; means for rotating said elongated body about the axis of symmetry thereof, thereby exposing a different face of the polygon such that the pump-laser beam target area is refreshed while maintaining the chosen pump-laser beam geometry; and means for translating said elongated body along the axis of symmetry thereof such that the pump-laser beam target area is refreshed while maintaining the chosen pump-laser beam geometry. ### Claim 8 (depends on 7) The apparatus of claim 7, wherein said means for rotating and translating said cylindrical body comprises: rotation apparatus; translation apparatus upon which said rotation apparatus is mounted; and means for controlling said rotation apparatus and said translation apparatus. ### Claim 9 (depends on 7) The renewable laser target of claim 7, further comprising a coating of a selected material and having a chosen thickness formed on the outer surface of said elongated body such that a selected wavelength of soft x-ray radiation is generated. ### Claim 10 A method for generating a renewable laser-pumped target for generating soft x-radiation, comprising the steps of: forming an elongated body having a polygonal cross section with flat outer faces on which a pump-laser beam target area is defined for a chosen pump-laser beam geometry, and having an axis of symmetry; rotating the elongated body about the axis of symmetry thereof, thereby exposing a different face of the polygon such that the pump-laser beam target area is refreshed while maintaining the chosen pump-laser beam geometry; and translating the elongated body along the axis of symmetry thereof such that the pump-laser beam target area is refreshed while maintaining the chosen pump-laser beam geometry. ### Claim 11 (depends on 10) The method of claim 10, further comprising the step of coating the outer surface of the rectangular step with a selected material having a chosen thickness, such that selected wavelengths of soft x-radiation is generated.