Progress of Magnetic Reconnection experiment in Linear Magnetized Plasma Device Xie, JinLin & LMPD group CAS KEY LABORATORY OF BASIC PLASMA PHYSICS UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA Suzhou, September 24, 2007
Jan 17, 2016
Progress of Magnetic Reconnection experiment in Linear Magnetized Plasma Device
Xie, JinLin & LMPD groupCAS KEY LABORATORY OF BASIC PLASMA PHYSICS
UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINASuzhou, September 24, 2007
Outline• Introduction
– What & Why & How– LMPD in USTC
• What we have done by now– Background plasma– Topology of the magnetic field for MR– Diagnostics / Data Acquisition System / …
• Preliminary result• Future plan
Introduction: Linear Magnetized Plasma Device in USTC
DC, RF & Helicon discharge source;
Bmax: 1000GuassTe:1~10evTi:0.03~0.5evDenisty:108~1013cm-3
Experimental chamber
LIFquad-probe
emissive probelangmuir probe
Nagoya antenna
13.56MHz,2KWMatch network
Radius
Plasma source: Helicon discharge
RF Power
Plas
ma
Den
sity
Typical ParametersTypical ParametersLCD
UCLA Pre-update LMPD LMPD
Machine typical Length[cm] 30 10 10
Plasma Denisty[m-3] 1018 1014 ~1016 1014 ~1019
Electron temperature Te[ev] 10 ~4 1~10
Ion temperature Ti[ev] 2 0.03 0.03~0.5
B for Magnetic Reconnection[T]
0.002 0.01 0.01
Ion mass Mi/Mp 40 40 1~40
Ion sound gyro-radius Rci[cm] 60 13 2~18
Ion skin depth [cm] c/wpi 60 4500 7 ~ 14300
Electron skin depth [cm] c/wpe 0.5 17 0.2 ~ 53
Electron free path [cm] 100 ~40 >100 ~ 3
Resistive time [ms] 1.5 0.2 ~ 0.1
Alfven time[us] 25 <1 0.1 ~ 10
Lundquist number ~60 300 10 ~ 1000
Background plasma for MR experiment
coil Vertical window
Pump
Hor. Window Experimental chamber
Plasma Source
Simulation result via OPERA
Magnetic field for reconnection
7 s 5 s
2500A
time
Curr
ent
Copper plate and Pulse current source
Diagnostics for MR • Characteristic for MR experiment in lab plasma
– High spatial resolution: small size Vs large enough S/N– Wide signal bandwidth: Low freq. ~ MHz or microwave High Spatio-temporal resolution
• What we have now:– 3D B dot probe B0 , B1 Current sheet, E…– Retarding grid energy analyzer EVDF & IVDF & flux– Electrostatic probes: Langmuir probe, emissive probe, Mach
probe… Ne, Te, Vf, Vp, Iion, Ie, Ion flux… – Laser induced fluorescence(LIF) IVDF & ion flux – Microwave antenna and related instrument EM radiation
– DAQ system: 12 channels x 5M; 128 x 2M; 2 x 60M
Vacuum chamber
precision platform for 2D scanning probe
Ion Saturation Current Electron Temperature
1 2 3 4 5 6 7 8 91
2
3
4
5
6
7
8
9
10
11
1.4
1.6
1.8
2
2.2
2.4
2.6
2.8
3
Reconstruction of the magnetic field linein order to verify MR process
x
Vacuum evolution
Research plan
• Verification of MR process in LMPD
• Heating and acceleration of electron & ion
• Electrostatic & electromagnetic turbulence
• ……….
Thank you!