1. 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

2. Outline Introduction What we have done by now Preliminary result
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

3. Introduction: Linear Magnetized Plasma Device in USTC
Experimental chamber
LIF
quad-probe
emissive probe
langmuir probe
Bmax: 1000Guass
Te:1~10ev
Ti:0.03~0.5ev
Denisty:108~1013cm-3
DC, RF & Helicon discharge source；

4. Plasma source: Helicon discharge
13.56MHz,2KW
Match network
Nagoya antenna
Plasma Density
RF Power
Radius

5. Background plasma for MR experiment
Typical Parameters
LCD
UCLA
Pre-update LMPD
LMPD
Machine typical Length[cm] 30 10
Plasma Denisty[m-3]
1018
1014 ~1016
1014 ~1019
Electron temperature Te[ev] ~4
1~10
Ion temperature Ti[ev] 2
0.03
0.03~0.5
B for Magnetic Reconnection[T]
0.002
0.01
Ion mass Mi/Mp 40
1~40
Ion sound gyro-radius Rci[cm] 60 13
2~18
Ion skin depth [cm] c/wpi
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

6. Magnetic field for reconnection
Simulation result
via OPERA
time
Current

7. Copper plate and Pulse current source

8. 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

9. LIF 原理示意图
GDB

11. precision platform for 2D scanning probe
Vacuum
chamber

12. Ion Saturation Current
Electron Temperature

13. Reconstruction of the magnetic field line in order to verify MR process

14. 1936 Phys. Plasmas 4 (5), May 1997
Study of driven magnetic reconnection in a laboratory plasma*
Masaaki Yamada,† Hantao Ji, Scott Hsu, Troy Carter, Russell Kulsrud, Norton Bretz,
Forrest Jobes, Yasushi Ono,a) and Francis Perkinsb)
Plasma Physics Laboratory, Princeton University, P.O. Box 451, Princeton, New Jersey 08543
~Received 12 November 1996; accepted 17 January 1997!

15. Vacuum evolution

16. Research plan Verification of MR process in LMPD
Heating and acceleration of electron & ion
Electrostatic & electromagnetic turbulence
……….

17. Thank you!