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Wissen für Morgen
Knowledge for Tomorrow
Institut für Technische Physik
Laser Thermal Removal Simulation Simulation results for single pulse irradiation: nHelix laser upscaling: 𝐸𝐿 = 20 𝑘𝐽, 𝑀2 = 2, 𝐷𝑇𝑒𝑙𝑒𝑠𝑐𝑜𝑝𝑒 = 8 𝑚, 𝑆𝑡𝑟 = 0.4, 𝑑𝑠𝑝𝑜𝑡 = 70 𝑐𝑚
Target: Al plate 2 x 2 x 0.1 cm, arb. orientation Monte Carlo: 0.42 µrad pointing, 10000 samples
• Large momentum scatter • Single pulse collision avoidance
Simulation of multi-pulse irradiation: Parameters as above; supplementarily: 𝑇0 = 327.8 239.4 𝐾 (dusk/dawn), 𝜀 = 0.09, up to 1000 samples each.
• Pulse limitation due to laser heating • Multi-pass engagements mandatory Future Research Issues
• Accumulation of heat and stress • Remote material reconnaissance • Remote temperature monitoring
Removal of Small-Sized Space Debris by Laser-Ablative Momentum Generation Stefan Scharring, Raoul-Amadeus Lorbeer, Michael Zwilich, Miroslav Zabic, Lukas Eisert, Daniel Hampf, Jascha Wilken, Dennis Schumacher, Markus Roth, and Hans-Albert Eckel
© USAF
True-Scale Experimental Proof Top: Experimental Setup Bottom: Dropping mechanism. Abbreviations: VAC: vacuum chamber, DM: dropping mechanism, P: periscope, L: Lens, LED: LED-lamp, HAL: halogen lamp, HSM: high-speed camera monochrome, HSC: high-speed camera color, BPC: beam profiling camera, LB: Laser beam, M: mirror, TSC: PTFE screen, HM: holding magnet, T: target, BP: burn pattern foil, PS: pressure spring, DA: dropping arm, HS: holding springs
• cm-sized targets (∅𝑡𝑎𝑟𝑔𝑒𝑡 < ∅𝑠𝑝𝑜𝑡)
• Laser pulse energy: 𝐸𝐿 = 80 𝐽 • IR laser: 𝜆 = 1064 𝑛𝑚, 𝜏 = 10 𝑛𝑠 • Stereoscopic 3D-tracking, ∆𝑡 = 1 𝑚𝑠 • Vacuum (< 2 Pa), free fall (µ-G) Experimental Results Object velocity changes ∆𝑣 after laser irradiation. Simulation results are indicated as point clouds.
• Large area to mass high ∆𝑣 • 1-pulse ∆𝑣 ≫ 10 𝑐𝑚 𝑠 • Momentum direction sensitive to
target orientation and position
Concept
• Surface ablation by laser pulses Recoil on debris target Perigee lowering Burn-up in atmosphere
• Targeted debris size: 1...10 cm
Ablative Recoil Measurements
Operational Safety Analysis
• Local exclusion zone at laser site • No-fly zone • Radar control • Reconcilement with air-traffic control
and space agencies
GSI Helmholtzzentrum für Schwerionenforschung
Fluence [J/cm²]
(Laser pulse energy aerial density)
Mo
me
ntu
m c
ou
plin
g c
oe
ffic
ien
t c
m
[µN
s/J
]
(Mo
me
ntu
m p
er
lase
r p
uls
e e
ne
rgy) 25
20
15
10
5
0 0 2 4 6 8 10 12
Solar cell Aluminum Polyimide
Laser parameters
Pulse energy: max. 3 mJ
Pulse duration: 8 ns
Wavelength: 1064 nm
Beam diameter: 0.7 mm
Laser parameters
Pulse energy: 10 kJ
Pulse duration: 1 - 10 ns
Wavelength: 1064 nm
Beam diameter: 5 m
Metal damage threshold
Skin: Max. permissible exposure (MPE)
MPE Human eye
MPE Human eye with binoculars
Direct irradiation / reflection
Diffuse reflection
Atmospheric scatter
Hazard
Flu
en
ce
𝜱 [
J/c
m²]
Distance 𝒛 [km]
Momentum Predictability and Heat Accumulation
Optical Engineering 2018
True-scale Experiment
Scientific Reports 2018
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Scientific Reports 2018