2004.3.28 物理学会シンポジウム 磁気プラズマセイル の可能性と 深宇宙探査への挑戦 宇宙航空研究開発機構 船木一幸
Spacecraft Propulsion Using Solar Energy Spacecraft with Magnetic Field Light from the Sun Solar Wind Thrust Mirror Solar Sail Thrust production by light pressure Magnetic Sail Thrust production by the solar wind dynamic pressure
1.??
1. (MPS) 2. MPS Inflation 3. JAXA/MPS
Original Idea of Magsail Top View Superconducting Coil Solar Wind Streamlines Side View 128km Solar Wind Vehicle System and Payload Support Magnetic Field Lines Proposal by Zubrin (JBIS, 1993) Solar Wind Dynamic Pressure ~ Magnetic Field of nt B-field by superconducting coil of 5mm diameter Current Density 10 10 A/m 2 ( difficult to construct/deploy)
Magsail with Plasma Jet (Magneto Plasma Sail, MPS) Mini-Magnetospheric Plasma Propulsion (M2P2) Proposed by R.M. Winglee, JGR, 2000 Bow Shock Magnetosheath Solar Wind Thrust Solar Wind Plasma Jet Thrust B-Field Lines Original Small B-field Inflated B-field by Plasma Jet Large interaction area -> Large thrust
(MPS) MPS MPS MPS
Comparison of MPS with EP Target of MPS both large T/P and Isp
MPS( ) Winglee MPS Inflation MPS
2. MPS( ) 2.1
~ ~ 2D
~ ~ Shock Front -30Re 30Re Magnetopause -30Re 30Re
D D C = D 2 ( ρu 2 )S ~ ~ C D ~0.95
2. MPS 2.2
2D-MHD Simulation of Magnetic Field Inflation 0.500 using resistive MHD model Axysymmetry θ Background Plasma ρ 0, p 0 :fixed u 0 =0 at r=r out r (polar direction), m Outflow Condition 0.375 0.250 0.125 0.000 Magnetic Flux Density (Dipole Field) 0.000 0.125 0.250 0.375 0.500 r, m at r=r in ρ in, u in, p in, B in : fixed Plasma Injection B-Field Lines r Symmetry r (polar direction), m 0.500 0.375 0.250 0.125 0.000 = 2.434e-03 Initial Plasma Distribution 10 18 /m 3, 3eV 0.000 0.125 0.250 0.375 0.500 r, m T r-θ Calculation Region 0.25 0.50 0.75 1.00 1.25 Pressure, Pa Initial Conditions
5.00 Numerical Result: Plasma Flowfield obtained by resistive MHD code (NIRVANA) t=0.22ms, B in =0.02T (200Gauss) p in =1.3Pa,T in =3eV, sonic inlet shock waves (large T) 5.00 Rm=σµ 0 ur-> (B-field frozen-in) r (polar direction), m 3.75 2.50 1.25 Background Plasma 10-4 Pa 3eV r (polar direction), m 3.75 2.50 1.25 5m 0.00 Acceleration r, m Deceleration 0.00 0.00 1.25 2.50 3.75 5.00 r, m 2500 5000 7500 100001250015000 Velocity, m/s Velocity Distribution 500 1000 1500 2000 25 Rm Magnetic Reynold s Number Distribution
Numerical Result: Magnetic Field Inflation by Plasma Injection B in =0.02T (200Gauss), p in =1.3Pa,T in =3eV, sonic inlet 5.00 5.00 r (polar direction), m 3.75 2.50 1.25 r (polar direction), m 3.75 2.50 1.25 0.00 0.00 1.25 2.50 3.75 5.00 r, m 0.00 0.00 1.25 2.50 3.75 5.00 r, m -5-4 -3-2 B-field, T -5-4 -3 B-field, T Magnetic Flux Density (without Plasma Injection, t=0) Magnetic Flux Density (with Plasma Injection, t=2.2e-04 s)
Summary of Numerical Result : Inflated Magnetic Field point of plasma injection Rm-> B-field frozen-in Magnetic Flux Tube MPS with plasma injection t=0.22ms t=0 without plasma Magnetic Dipole Magnetic Flux Density Model of Magnetic Field Inflation B-field inflation is also confirmed in the case of resistive MHD model. However, currently, only transient results are obtained.
3.
Research Topics remains
H16 H17 MPS H18