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11 Implementation of remote capabilities for the planeterrella experiment at the Princeton Plasma Physics Laboratory planeterrella.pppl.gov/RPX Adrianna Angulo 1 , Arturo Dominguez 2 , Andrew Zwicker 2 1 Florida International University, Miami, Florida 33199 2 Princeton Plasma Physics Laboratory, Princeton, NJ 08543 1 [email protected] 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
