“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…
UNCLASSIFIED/ ,'F&II. &FFUiil'°'I! l!llili a,112~·
Chapter 2: Laser Lightcraft Nanosatellite Propulsion
Laser propulsion is a new and exceptional method for reaching space. By launching
spacecraft on a beam of electromagnetic radiation, researchers will have developed the
first new method of achieving orbit since the late 1950's. In this concept, a remote or
ground-based energy source, such as a ground- or space-based laser beam generator,
transmits power to a spacecraft via a beam of electromagnetic radiation [1-8]. The
spacecraft collects the beam energy and uses it to power the propulsion system. This
concept has the advantage of using the ambient air as the working fluid in the
atmosphere and carrying propellant only for use outside the atmosphere, leaving the
energy source for heating the propellant on the ground. This results in a tremendous
weight reduction and improved performance benefit for the spacecraft because a large
propellant mass and heavy energy source are not carried onboard.
The laser-propelled vehicle, called "Ughtcraft" because it flies on a beam of laser light,
is designed to harness the energy of a laser beam and convert it into propulsive thrust.
In the earliest laser-propelled rocket designs, beamed energy from a ground-based
laser (with near-visible wavelengths) is absorbed by a heat exchanger onboard a
rocket, and is transferred to a working fluid. The heated fluid (hydrogen, ammonia,
etc.) then produces thrust by expansion through a nozzle as in a conventional chemical
rocket. An alternative to this scheme is to use the beamed-energy to ablate an
onboard solid propellant (such as Delrin) to generate thrust. However, a more recent
incarnation of this concept, developed by the Air Force Research Laboratory (AFRL) at
Edwards AFB, CA, is for the Ughtcraft to operate in two propulsion modes: airbreathing
(detonation wave) and rocket ablation (deflagration). The Lightcraft operates in air
breathing mode up to Mach 5 and 30 km altitude, and in laser thermal rocket mode
(using liquid, gaseous, or Delrin ablation propellant) in space [7, 8, 9-16]. Figure 1
shows the Air Force X-25LR (25 cm diameter) Ughtcraft concept. The Air Force X-SOLR
Lightcraft has twice the diameter as the X-25LR.
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UNCLASSIFIED//F&II. &FFUilAI! l!llili 8111!1/