“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/ /P&tl err1e1xc 65£ 911[ I
0.001 duty cycle, has a helical film antenna that increases its gain and doubles as a
solar sail for infrequent stationkeeping maneuvers, and has a tether for coarse gravity
gradient stabilization. A SO km tether supports the feed, transmitter, and DGPS
reference assembly against a counterweight. The antenna lens is 2 km x 4 km.
The effective area of the array is the same as that of a SO m diameter filled aperture.
The total effective RF radiated power of the system is 3 GW peak and 3 MW average.
Although specific performance calculations have not been done for this concept, these
powers are so large that the radar should have the sensitivity from its location in GEO
for detecting and tracking many targets simultaneously and most "low observable"
targets as well because they are all designed and oriented so as to have their low
observables in near-horizontal directions. Three constellations would provide
essentially complete global coverage. The entire constellation weighs about 11,000 kg
in GEO (this could be reduced in the future to 110 kg if Buckytubes are used to
construct the system) and can be emplaced and replaced incrementally using laser-
powered Lightcraft launch vehicles or even small conventional launch vehicles. It could
even be funded incrementally.
Simple, Distributed, Hyperspectral Sensor
This concept presents an unconventional method of implementing a hyperspectral
sensor of great spectral and spatial resolution. Its implementation would allow the
detection of very many spectral intervals simultaneously, and it has a small field of view
from GEO so that the instrument can dwell on and resolve particular targets of interest.
It also has a large field of regard so that one spacecraft covers a significant fraction of a
hemisphere.
The concept uses a Fresnel zone plate, which is oriented roughly parallel to the local
horizontal just below GEO. It is supported by a tether that extends well above the GEO
altitude, and may or may not have a counterweight at the top end. The gravity
gradient causes the ensemble to remain Earth pointing along the local vertical, with its
center of mass in GEO.
The Fresnel zone plate has a long focal length, and thus the surface and ring locations
can be imprecise compared with conventional optics. In addition, the lens is a thin film
membrane and will be light and inexpensive. It is highly frequency dispersive, and thus
its focal length is a sensitive function of wavelength. Small, self-contained optical
sensor nanosats are placed on the tether at many locations with each nanosat's optics
filtered for response at only that narrow spectral region focused at its distance from the
lens. The nanosats can transmit directly to the ground or their signals can be combined
in one transceiver, also on the tether.
This system has a 100 km long tether, which weighs only a few kilograms in GEO. The
Fresnel zone plate is 100 m in diameter, has a collecting aperture equivalent to a 30 m
filled aperture, and requires only a surface accuracy of centimeters in the visible light
region. It is constructed of thin film with deposited aluminum rings and is an adaptive
piezoelectric membrane kept flat by an electron beam in response to an optical figure
sensor. MEMS FEEP thrusters are at the sensor's periphery for attitude control, with
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