“BEAMS”49 pages
- p. 3 …Free-Electron Laser Electron Beam Phase-Space Evolution ....................... 59
Figure 31. Recirculating-Beam FEL System ........................................................... 60…
- p. 4 …HEL Beam Pointer/Tracker ................................................................... 65
Figure 35. Basic Shared Aperture Beam Control System ......................................... 66
Figure 36…
- p. 7 …This can only be achieved via laser propulsion in
which the laser beam energy that is…
- p. 15 …By launching
spacecraft on a beam of electromagnetic radiation, researchers will have developed the
first new…
- p. 16 …The laser beam's pulse
interacts with the mirror, spreading out and focusing into an annular…
- p. 17 …1) power supply; 2) high-power (megawatt-class)
laser beam generator/transmitter using novel beam optics…
- p. 20 …is to the right and the laser beam strikes the stretched-out parabolic
mirror/propulsion section…
- p. 21 …It
requires a beam power of 0.1 to 1 MW per kg of vehicle mass…
- p. 22 …The ground-based
megawatt-class laser beam generator is state-of-the-art technology. The cost…
- p. 25 …Figure 8 illustrates the adverse beam
propagation geometry associated with ETO laser propulsion by means of…
- p. 26 …Attenuation Effects on Captured Laser Beam Power 261.
0.4
0.J
0.2
0.1…
- p. 27 …Unfortunately the demonstrated laser beam power levels for the attractive 1.62 μm
wavelength, which suffered…
- p. 28 …Beam combining
of several 1 MW (or higher) FELs can achieve a total combined beam output…
- p. 31 …Appropriate rotation of a high-energy laser beam,
emanating from a ground/sea-based laser, guides…
- p. 32 …Appropriate rotation and translation of a high-energy laser
beam, emanating from a moving aircraft, guides…
- p. 33 …But
multiple target interception within allowable time is limited by relatively long beam-
riding time needed…
- p. 37 …In this case, it is envisioned that the high-
pulsed power within high-energy laser beams…
- p. 39 …In this case, airborne laser beams at 12 km altitude will not suffer the
significant propagation…
- p. 41 …sidelobes, creates multiple beams, and steers the ensemble of the
individual beams anywhere on Earth. The…
- p. 42 …Each picosat is gravity-
gradient stable, has a dipole array facing Earth, and a broader beam…
- p. 43 …Commands for beam sweep delays are superimposed on the time delays of each
nanosat. Each nanosat…
- p. 44 …piezoelectric membrane kept flat by an electron beam in response to an optical figure
sensor. MEMS…
- p. 46 …technical issues include large wavelength and
atmospheric absorption of the laser beam.
• Carbon Monoxide (CO) Laser…
- p. 47 …125 Hz@ 20μs.
• Laser power, P = 2.5 MW/beam x 4 beams = 10 MW.
• Laser…
- p. 50 …Each power oscillator optics module transmitting a 2.5 MW beam of
10.6 μm wavelength…
- p. 52 …Adding an eight amplifier chain that the system was designed for will
increase the beam power…
- p. 53 …However,
BSSSL beam power can be scaled up further by improving presently known gain media
and…
- p. 54 …scalable
to 1 MW beam power within 2 years.
Typical solid-state lasers have the following…
- p. 55 …A new technology that enables the scaling-up of BSSSL beam power is a recently
developed…
- p. 56 …at the same time increasing the average
beam power.
Figure 21. Phase Change Materials Allow Storage…
- p. 57 …This exponential growth in beam output power is the result of many factors,
including the parallel…
- p. 58 …Microlens -O _
,:1
Incoherent Beam Combining 'Ind1vidually Incoherent Gaussian Beams i=L
Controlled
/_/Steering • ... o~bined…
- p. 59 …Neodymium
Thulium (Tm 3+), Holmium
- Range of beam wavelengths(),) produced: 0.48 μm to 2.9…
- p. 61 …Multlmode Fiber Lasers
50kW Multimode
Output beam quality BPP-1 o
M"2-33
DC EDE…
- p. 62 …The resulting laser beam photon energy depends on the
electron energy, the undulator period, and (weakly…
- p. 63 UNCLASSIFIED/ /F8~ 8FFl&I.«1k WliEii a,.klf
electron beam
( \ I,:--- ■■>ti■--
undulator
)
resonator mirror
0…
- p. 64 …The superconducting accelerator gives good
efficiency and gradient while recirculation of the electron beam recovers beam…
- p. 65 UNCLASSIFIED/ /F&~ 8FFHiil.«1k 1!181! &••kY
- K"' 1.5.t
• Electron Beam:
- Photocathode injector creates…
- p. 66 …HIGH ENERGY LASER BEAM CONTROL
··costs could be reduced to as low as $20 per kg…
- p. 67 …The typical HEL beam control system includes:++ 1) a gimbaled
beam director, 2) tracking and pointing…
- p. 68 UNCLASSIFIED//F&II. &FFiii,111!! l!llili &HI!¥
A novel new HEL beam control architecture being…
- p. 69 …HEL Beam Pointer/Tracker (courtesy of the Directed Energy Professional
Society).
In summary, this new architecture…
- p. 70 …The BILL is a solid-state, kilowatt-class laser
that measures atmospheric conditions, allowing the beam…
- p. 71 …All of these HEL beam control innovations can be quickly adapted to laser propulsion
applications with…
- p. 72 …The entire Lightcraft launch
system is comprised of a ground, sea, or airborne laser beam generator…
- p. 73 …New beam
control devices and high-power optical train combinations have a resulting beam line
that…
- p. 75 …N. (1983), "Advanced Beamed-Energy and Field Propulsion Concepts,"
BDM/W-83-225-TR, BDM Corp…
- p. 76 …N. (2001), "World Record Flights of Beam-Riding Rocket Lightcraft:
Demonstration of 'Disruptive' Propulsion Technology," AIAA…
- p. 77 …of the 6 th Int'! Symposium on Beamed Energy
Propulsion, edited by C. R. Phipps, AIP…
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spacecraft. This creates coherent RF or optical apertures that are essentially unlimited
in size, which could offer unprecedented high-resolution radiometry, hyperspectral
imaging, radar, and RF interception (for mapping, surveying, MASINT, SIGNIT), etc.
Launching laser-propelled Lightcraft nano-/pico-satellites to LEO requires megawatt-
class lasers. TEXTRON Systems Corporation's proposed 10 MW electron gun-driven
CO2/gas mixture laser is a multi-megawatt-class system that can be implemented now
because this technology requires little or no additional R&D. This system offers realistic
near-term, low-cost Lightcraft launch capability. However, this system is large,
requires a large amount of gas propellant to fuel the laser, and the system
infrastructure will cost over $200 million.
The newly emergent bulk slab solid-state, high-power fiber, and free-electron laser
technologies being explored by the various DoD directed energy weapons programs
offer higher electrical-to-optical efficiencies and overall laser performance, compact and
portable system size, less complexity and smaller weight, all at much lower system and
infrastructure cost. These lasers are scalable to megawatt-class beam power, and so
we roughly estimate that the overall system and infrastructure cost to deploy such laser
systems to launch a Lightcraft to LEO will be from several factors to an order of
magnitude (or more) lower than for the electron gun-driven CO2/gas mixture laser
system.
Removing the waste heat produced by high-power laser systems is an important factor
driving the physical limitations of scaling up the beam output power. An innovative
matched-refractive-index liquid is used to rapidly remove the heat produced by a 150
kW bulk slab solid-state laser weapon while the very high surface area-to-volume ratio
of high-power fiber lasers allows for the rapid removal of heat from the gain medium
without the need for external cooling. Phase-change materials are being explored and
devices using such materials have recently demonstrated the ability to store very large
quantities of the waste heat produced by high-power solid-state lasers, which is a
different way of rapidly removing large amounts of heat from the solid-state gain
medium. Unlike solid-state laser systems, free-electron lasers are not affected by heat
problems while their gain medium (a vacuum) cannot be damaged.
Launching a laser-propelled Lightcraft nanosat/picosat from the ground, sea, or air into
LEO requires controlling and steering the high-energy laser beam, while at the same
time making real-time adjustments to account for platform motion, optical train and
atmospheric effects on beam propagation, so that the beam maintains high quality,
low-loss, precision contact with the Lightcraft during the entire flight. Recent technical
innovations in optical train design and other system architecture have evolved beam
control devices for high-energy laser weapons toward new implementations. New beam
control devices and high-power optical train combinations have a resulting beam line
that is considerably simpler, smaller and lighter than current architectures. Almost
every component in the beam line performs multiple functions, thereby dramatically
reducing the high-power optical component count. This approach also packages all
beam control sensors, processors and drivers into a single turret assembly.
In 2005, the AFRL/PRSP (Edwards AFB, CA) concluded their laser Lightcraft propulsion
R&DTE program before launching a Lightcraft test vehicle into LEO was demonstrated
69
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