“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// I OK 01 I ICIAE ""I! enc,
• ri = 1: this is the conversion efficiency of laser rocket propellant-thrust-jet KE into
vehicle KE, in which the propellant/laser is designed so that the rocket thrust-jet
velocity is equal to the vehicle velocity throughout the mission, i.e., the laser
rocket has variable lsp "" 100 seconds at beginning of mission to 1000 seconds at
end of mission;
• up = 0.5: u is efficiency of laser energy absorption and p is efficiency of
conversion of propellant internal energy into thrust-jet KE;
• y = 0.7: this is the atmospheric transmission efficiency;
• Eiaser = 750 MJ.
These numbers multiplied together give a vehicle KE = 262. 5 MJ in LEO. If the effective
change in velocity (Av) required to get to LEO is 10 km/sec (8 km/sec orbital velocity +
1 km/sec for gravity+ 1 km/sec for drag loss), then 1 kg in LEO has 50 MJ of energy
investment and a 5.25 kg payload in LEO has 262.5 MJ of energy investment.
The 60 kg/sec mass flow requirement of the 3: 1 N2/C02 lasing gases means that a
mass flow of 15 kg/sec of CO2 and 45 kg/sec of N2 is required. For the 300 seconds of
thrust we will therefore need 4.5 tons of CO2 and 13.5 tons of N2 gases (we are
neglecting the tiny amount of H2) to launch a payload to LEO. Liquid CO2 costs $100
per ton and liquid N2 costs $154 per ton. The total lasing gas cost is therefore $450 for
the liquid CO2 and $2,079 for the liquid N2. Adding these two gas fuel costs to the $104
cost of the required electrical energy gives a total of $2,633 to launch a 5.25 kg
payload to LEO. This result represents a cost of $501 per kg of payload (or $228 per
pound) launched to LEO, which is 44 times lower than the oft-quoted standard space
launch industry cost of $10,000 per pound for conventional chemical propulsion rockets
systems.
However, this cost figure needs to be slightly adjusted to account for other factors. If
we use the N2/C02 gases at a temperature of 217 Kin the laser, then we will have to
boil the liquid CO2 and the liquid N2 with additional heating of the gaseous N2. Boiling
4.5 tons of liquid CO2 at 217 K requires 1,175 MJ of energy, boiling 13.5 tons of liquid
N2 at 77 K requires 2,683 MJ of energy, and heating the 13.5 tons of gaseous N2 from
77 K to 217 K requires 1,890 MJ of energy. Therefore, the additional energy required
to prepare the laser gases is 5,748 MJ (= 1,175 MJ + 2,683 MJ + 1,890 MJ), which
represents an additional electricity cost of $160. Adding this additional energy cost to
the previous total of $2,633 gives a final total cost of $2,793 to launch a 5.25 kg
payload to LEO. This new final result represents a cost of $532 per kg of payload (or
$241 per pound) launched to LEO, which is 41 times lower than the space launch
industry cost of $10,000 per pound for conventional chemical propulsion rockets. Note
that this final cost estimate excludes the operations, life-cycle, and maintenance costs
that are listed in Table 1, which were based on the use of a bulk solid-state laser.
47
UNCLASSIFIED//F811. 8FFl81*L 1!1!11! 9HLY