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CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
BEGIN:VEVENT
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UID:UW-Physics-Event-2611
DTSTART:20120220T180000Z
DURATION:PT1H0M0S
DTSTAMP:20240328T083650Z
LAST-MODIFIED:20120216T145740Z
LOCATION:2241 Chamberlin
SUMMARY:Impulsive Fast Reconnection via Flux Rope Dynamics\, Plasma Ph
ysics (Physics/ECE/NE 922) Seminar\, Hantao Ji\, Princeton Plasma Phys
ics Laboratory
DESCRIPTION:Magnetic reconnection\, the efficient release of magnetic
energy by topological rearrangement of field lines\, is one of the mos
t important and fundamental plasma processes in space\, solar and more
distant astrophysical plasmas. The modern collisionless models predic
t that ions exhaust through a thick\, ion-scale layer while mobile ele
ctrons leave through a thin\, electron-scale layer\, allowing for effi
cient release of magnetic energy. While ion layers have been frequentl
y detected in space and studied in detail in the laboratory\, the diss
ipation on the electron scales near the X-line remains largely unknown
. The discrepancies [1-3] between the measured thickness of the electr
on diffusion layer in MRX and best available 2D kinetic simulations su
ggest that the electron scale dissipation must be 3D in nature. In thi
s talk\, the most recent experimental results from MRX and their compa
risons with 3D kinetic simulations will be discussed. It is found that
impulsive fast reconnection is caused by a disruption of the current
channel localized in 3D space\, associated with a burst of electromagn
etic fluctuations. There exists substantial evidence that these impuls
ive behaviors are caused by 3D flux rope dynamics [4]. Looking into th
e future\, a new theme of multiple X-line reconnection in a phase diag
ram [5] possibly provides solutions for fast reconnection in large spa
ce and astrophysical systems and for efficient particle acceleration o
ften observed there. Scientific opportunities for a next generation la
boratory experiment based on MRX to study magnetic reconnection in suc
h regimes directly relevant to space and astrophysical plasmas will be
described.
\n
\n[1] H. Ji et al.\, GRL 35\, L13106 (2
008).
\n[2] S. Dorfman et al.\, PoP 15\, 102107 (2008).
\n[3] V. Roytershteyn et al. PoP 17\, 055706 (2010).
\n[4] S
. Dorfman\, Ph. D. Thesis (2011)\; to be submitted to PRL (2012).
<
br>
\n[5] H. Ji and W. Daughton\, PoP 18\, 111207 (2011).
\n
URL:https://www.physics.wisc.edu/events/?id=2611
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