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Implementation of remote capabilities for the planeterrella experiment at the

Princeton Plasma Physics Laboratory planeterrella.pppl.gov/RPX

Adrianna Angulo1, Arturo Dominguez2, Andrew Zwicker2

1Florida International University, Miami, Florida 33199

2Princeton Plasma Physics Laboratory, Princeton, NJ 08543 1aangu003@fiu.edu

The Terrella and Planeterrella

The Remote Planeterrella Experiment

Phenomena Observations and Explanations

The Terrella

• Voltage applied to electrode (the sun) and a

suspended sphere (the Earth) in a vacuum

• Initially developed by William Gilbert ca.1600

• Further developed by Norwegian physicist

Kristian Birkeland in 1896

• Initial understanding of polar lights

• Simplification of Solar-terrestrial system

Birkeland demonstrating his rendition

of the Terrella

The Planeterrella Electrode

Small Sphere

Large Sphere

Website and Education

Future Plans

References

Simulation Electrode (V) Large Sphere (V) Small Sphere (V)

Stellar Ring Current Off -1500 Off

Magnetopause Off -1500 -500

Solar Corona -500 Off -1000

Magnetosphere -500 -500 -1000

Auroral Ovals -2000 -1000 Off

RPX Configurations

Solar Corona The small sphere radiates electrons and

ionizes the surrounding gas. The localized

magnetic field exerts a force on the plasma

that increases the pressure without as much of

an increase in the density. The magnetized

region rises until it reaches the object’s

equivalence of a photosphere. The electrons

are repelled from the poles that result in dark

spots or coronal holes.

All of the configurations incorporate the same basic premise:

• Electrons are emitted from a source

• Electrons interact with the magnetic field of an object

• The gradient of the magnetic field creates a gradient drift which

causes the electrons to orbit the object

• Electrons collide and ionize the gas

• Gas returns to equilibrium- releases energy as light

1. Lilensten, J., Barthélémy, M., Simon, C., Jeanjacquot P., Gronoff, G., 2008. The Planeterrella, a pedagogic experiment in

planetology and plasma physics, DOI: 10.2478/s11600-008-0079-x,230-235, Acta Geophysica, vol.57, no. 1, pp. 220-235,

2008.

2. Rypdal, K. and Brundtland, T.: The Birkeland terella experiments and their importance for the modern synergy of laboratory

and space plasma physics, J. Phys., 7, C4-113–131, 1997

3. Cheng, C. C., 1998: The solar wind control of the magnetopause shape: A comparison of a model magnetopause and

empirical models. Terr. Atmos. Ocean. Sci, 9, 239 – 254.

4. "La Planeterrella - Le Simulateur D’aurores Polaires." La Planeterrella - Le Simulateur D’aurores Polaires. N.p., 2014. Web

5. Gebhardt, Olivia. "The Planeterrella Experiment." Olivia Gebhardt. Princeton Plasma Physics Laboratory, n.d. Web.

<http://olivia-gebhardt.squarespace.com/planeterrella/>

Auroral Ovals The electrons emitted by the large sphere

deviate towards the poles and along the

electric field between the large sphere

and the electrode. The intensity of the

auroral ovals due to the higher density of

electrons.

The Magnetosphere Although it is not one of Lilensten’s original

configurations, this configuration offers a

static observation of the magnetosphere.

The magnetosphere is the region where

charged particles (in this case electrons)

interact with and are deflected by the

object’s magnetic field.

Stellar Ring Current The electrons emitted by the large

sphere are confined to the magnetic

equator due to magnetic mirror. The

magnetic mirror occurs when a charged

particle (the electron) is reflected from a

region of stronger magnetic field.

LabVIEW Code

DAQ Device

• PPPL planeterrella, constructed in

2013 by Science Education Dept.

• Reproduces Lilensten’s planeterrella

• Current work is to enable live stream

and online control of planeterrella at

PPPL

• Users control magnitude of voltage of

the large sphere, small sphere and

electrode

• Buttons with preset configurations of

phenomena

• Accessible world-wide

• Pressure kept at 250mTorr

The RPX

Lilensten demonstrating his

planeterrella

• Terrella modified in 2008 by Jean

Lilensten → the Planeterrella[1]

• The planeterrella is more flexible

and simulates more phenomena

than Terrella configuration

• Voltage applied to pin-like electrode

and two magnetized supported

spheres in a vacuum

• Electrode → Plasma Sheet,

• Spheres → Planet or Plasma Sheet

• Electrode height and sphere positions are adjustable

• Objects are given an interchangeable positive or

negative polarity

• Discharge between objects creates plasma affected by

the sphere’s magnetic fields

Web Content • Introduction

- What am I looking at?

- Space Physics on Earth?

- How can I make it glow?

- What is a plasma?

- Why does the plasma glow?

• Controls

- Voltage

- Polarity

• Phenomena

- Stellar Jets

- Solar Corona

- Stellar Ring Currents

- Auroral Ovals

- Magnetosphere

The RPX website layout was created with a combination of HTML5,

CSS, Jquery, and Javascript. The user interface controls were

developed using WebUI Builder. The layout of the website emulates

the layout of the Remote Glow Discharge Experiment website.

The RPX is a captivating introduction to the link between the Earth space

environment and space weather that is accessible remotely.

Physics behind phenomena can be explained at different levels:

• Explanations made as complicated or simplified as audience prefers

• Accessible to users with a range of academic backgrounds (elementary

school – PhDs)

• Allows the user to control space-like phenomena

Popularization of space weather and science

• Produces engaging colors, allures a diverse audience

• Artists attracted by auroras. Art is then a driver to improve scientific outreach

Schematic view of the different current systems which shape the Earth's

magnetosphere

Magnetopause The magnetopause is the boundary between the

planet’s magnetic field and the surrounding

plasma. Electrons emitted from both objects

meet at a common region and are concentrate

enough so that the light emitted by the collisions

becomes visible

Small Sphere

Small Sphere

Electrode

Install additional diagnostic and parameter controls

Greater Phenomena simulation and Flexibility

• Bipolar Remote Capabilities → Stellar Jets

• Electromagnet → Auroral spot on Uranus

• Remote Pressure Regulator → Van Allen Belts

Quantitative Analysis

• Voltmeter, Gaussmeter, Ammeter

• Remote Position Control → measure effects distance has on E and B field

Conclusion

The website includes supplemental information

that explains the physical interpretation of plasma,

the controls, and astrophysical phenomena