RESEARCH POSTER PRESENTATION DESIGN © 2012
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Aurora Borealis Experiment: A Planeterella for
Education and Outreach
The Planeterella is an experiment, invented by Jean
Lilensten of the Labartoire de Planetologie de Grenoble in
France, designed to simulate various space plasma
phenomena, typically aurorae. A Planeterella consists of
two differently sized spheres with magnets inside them,
and a copper electrode. Usually at least one piece is
positively biased while the other is negatively biased.
When the potential between the cathode and anode reach
breakdown voltage, plasma is formed. The plasma
simulates space plasma around planets created by solar
wind. We have made a modified version of the
Planeterella, called the Aurora Borealis Experiment
(ABX), based upon Lilensten’s plans.
Introduction
How it Works
Construction
Results
Conclusion and Future Work
Mercer County Community College*, Princeton Plasma Physics Laboratory+
Aurora Borealis Experiment
Courtesy of: http://www.globalwarmingclassroom.info/earth_magnetosphere.htm
• Create a demonstration of space plasma
phenomena that can be used for students at
a variety of levels
• Bell jar, aluminum spheres, permanent
magnets, two DC power supplies used to
create necessary conditions
• The transfer of charged particles from a
magnetic sphere represent solar wind
• Gas is air, plasma is created at breakdown
voltage which depend upon separation of
spheres, pressure, and voltage
• Under correct manipulation, magnets inside
the spheres create what appears to be
aurorae
Electrical Setup
Vacuum Setup
Left: Vacuum pump
Top Right: Exhaust pump
Bottom Right: Pressure
gauge and control
Left: PPPL’s Aurora
Borealis Experiment
Left: Entire view of vacuum
setup ready for use
Neodymium permanent magnets with a surface
field of at least 1 Tesla must be used.
Right: Birkeland’s
original Terella c.1895
Right:
Planeterella by J.
Lilensten, the
basis for PPPL’s
Planeterella
Left: Aluminum base
plate drafted in Autocad
and cut in PPPL metal
shop
Right: PLA pieces (in
yellow) made from 3D printer along with
aluminum spheres and copper electrode
• Left sphere is
negative, right is
positive
• Magnets in both
spheres are
horizontal
• No apparent
influence of
magnets
Left: Autocad drawing of
aluminum base plate
At 3 inch separations, most discharges occurred
between 450-550V at pressures of 75-95mTorr.
Power supplies used. The left
supply is set to positive while
the right supply is set to
negative
• Left sphere is
negative, right is
positive
• Vertical magnets in
left sphere and none
in right sphere
• No apparent
influence of magnets
• Left sphere is
negative, right is
positive
• Vertical magnets in
left sphere horizontal
magnets in right
• Magnets on right
appear to deform the
plasma around the
left sphere
• Arcing to the base plate needs to be fixed
• Addition of electromagnets
• Move the spheres while under vacuum
• Increase strength of permanent magnets
• In some configurations the magnets are able
to influence the system
• Optimal breakdown conditions: 2.75 inch
separation, 500V, 70mTorr
Michael McNulty*+, Andrew Zwicker*, Andy Carpe*, Josh Bloom*