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

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

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；

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

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

Magnetic field for reconnection Simulation result via OPERA time Current

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

LIF 原理示意图 GDB

precision platform for 2D scanning probe Vacuum chamber

Ion Saturation Current Electron Temperature

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

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!

Vacuum evolution

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

Thank you!