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This Defense Intelligence Reference Document from the Defense Intelligence Agency, dated 1 November 2010, was produced under the Advanced Aerospace Weapon System Applications (AAWSA) Program. It describes nanosatellite technologies and proposes launching nanosats into orbit with laser Lightcraft propulsion. It also covers a weapon mission selection study and multi-megawatt laser options. The author recommends that the Department of Defense and NASA bring Lightcraft R&D back to the United States and restart the X-50LR flight demonstration program.
“Sea”14 pages
UNCLASSIFIED/ /F&~ 8FFHiil.«1k 1!181! &••kY - K"' 1.5.t • Electron Beam: - Photocathode injector creates picosecond electron pulses at 7 MeV. t - Superconducting accelerator increases electron energy to 100 MeV. - Peak current: 1100 A. - Average current: 0.5 A. - Length: 0.1 mm. - Radius: 0.1 mm. - Electron beam recirculated for energy recovery. • Optical resonator based on short Rayleigh length optical mode (see Figure 32): - Cavity length (resonator mirror separation distance), 5: 16 m. - Optical waist (natural mode width), wo: 0.1 mm. - Mirror radius of curvature, w: 2.6 cm. Rayleigh length, zo: 2 cm. • Optical (Laser Beam) Output: - Power: 2 MW. - Wavelength, /,: 1 μm (tunable by controlling electron beam, undulator and resonator properties). • Short Rayleigh length§ (SRL) optical mode gives several advantages: Reduces optical intensity on resonator mirrors to avoid mirror damage. - Single optical wavefront is amplified giving excellent beam quality. - FEL interaction is altered with SRL mode. - SRL intensifies interaction at mode focus. ■ Rapidly changing optical amplitude and phase. - SRL accelerates electron bunching and energy extraction ■ Electrons interact with optical radiation field along undulator. ■ Electrons "see" intense optical electric field at mode focus. ■ Electrons "see" rapidly changing optical radiation phase at mode focus. • Natural mode width/optical waist (for 5 ~ meters & laser beam f. ~ microns) is millimeters. • High-power lasers typically run in multiple transverse modes; however: - High-power FEL requires short Rayleigh length and small optical waist. - High-power FEL amplifies single mode without damage to gain medium (a vacuum). • FEL efficiency increases as Rayleigh length decreases. • For megawatt-class FEL system, high operating current plus active mirror alignment system acts to stabilize optical mode against Naval warship vibrations, 'K"' eB,rn,f,,.,nol2rcmC, where e is the electron charge, B,.,, is the root-mean-square magnetic field strength, /,,no is the undulator period, mis the electron mass, and c is the speed of light. 'MeV "' Mega-electron Volt. •sRL = distance for the area of the beam waist to double. 61 UNCLASSIFIED/ }FQA: QFFIQIOk WEliii Qllk>f
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Report, from the dia collection. The PDF is mirrored here; the original link is under it. 77 pages are in the text index: search them above, or from the library's search.