PPPL Plasma Lobby Display Project

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PPPL Plasma Lobby Display Project

• Fran Tursi and Melinda Flores
• July 13th July 24th

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Lobby Display
By Dana Arose, high school student
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Our contribution

• First plasma made using lobby display

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Our Contribution

• Mass-Flow Controller (MFC)

MFC connection ?
0-5 VDC ?
-15 VDC ?
15 VDC ?
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Our Contribution

• Mechanical Control Valve

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Our Contribution
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Results

• Questions
• What pressure will produce pretty plasma?
• Will the mechanical control valve be able to
  maintain this pressure for 8 hours of operation?

• Answers
• 125 mTorr 135 mTorr
• Yes. Assuming pressure change is constant (2
  mTorr /3 hours)

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Unfinished Business

• Safety valve
• MFC with better power source
• Touch screen/timer

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Plasma Lab The Glow Discharge

• Senior Physics
• St. Peters Prep
• Lesson Plan by Melinda Flores and Fran Tursi
• floresm_at_spprep.org and tursif_at_spprep.org

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Lesson Objective

• To learn what a plasma is
• To understand how to create a plasma
• To identify the conditions needed to create
  plasma efficiently

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Anticipatory Set

• What are the states of matter?
• Classify the following states of matter.

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Anticipatory Set

• What are the three states of matter?
• Classify the following states of matter.

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Objective Purpose

• Over 99 of the universe is in the plasma state
  of matter!
• By researching plasma we can achieve greater
  understanding of the universe and reap the
  benefits of its practical uses.
• We will study how plasma is created and how it
  can be produced efficiently.

• Practical Uses include
• New manufacturing techniques
• Consumer products
• Prospect of abundant energy
• More efficient lighting
• Surface cleaning
• Waste removal
• Aerodynamic innovations

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Instructional Input and Information

• Matter can move from one state to another by
  applying energy to it.

• When energy is applied the matter becomes more
  active and changes states.

• In plasma you not only have neutral atoms, you
  have ions and electrons.

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Instructional Input and Information

• Different factors affect what state matter will
  be in (i.e. pressure and temperature)
• Recall the following graph from your chemistry
  class

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Instructional Input and Information
Paschen Curve

• In studying plasma we will look at the following
  factors
• pressure
• distance between parallel plates
• breakdown voltage

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Instructional Input and Information
What makes plasma a state of matter? How do you
know that plasma is created?
Three specific events of interest.
1. Electrons are coming close to ions
? Neutral atoms (lowest energy)
2. Electrons collide with neutral atoms (high
speed)
? ionized atom and electron (greatest energy)
3.Electrons collide with neutral atoms and excite
them
? Light from neutral atom
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Modeling
You apply heat or energy You apply energy

• How do we go from solid to liquid? From liquid
  to gas?
• How do you think we will go from gas to plasma?

We have a florescent bulb with mercury vapor.
What do you think will happen when we apply
electrical energy to the vapor?
Plasma will be created !
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Monitor and Adjust

• Popsicle stick questions
• How many states of matter are there? Name them.
• Describe the characteristics of each state of
  matter.
• What is the most prevalent state of matter in the
  universe?
• How do we move from one state of matter to the
  next?

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Guided Practice

• Activity Glow Discharge
• Using a vacuum and electrical system students
  will create plasma (safety and procedure will be
  discussed first).
• Student will work with two variables, pressure
  and distance in order to determine their effect
  on voltage needed to create plasma (breakdown
  voltage).
• Students will label and draw the apparatus,
  record data at given distances, create a Paschen
  curve (pressure x distance vs. breakdown
  voltage), and determine the pressure-distance
  product needed to create plasma using the least
  amount of voltage.

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Guided Practice

• Monitor Their Practice
• Observe students in groups and ask questions to
  ensure students
• Have correct setup
• Vary distances between plates
• Vary pressure
• Record pressure, distance, total voltage,
  voltage of the resistor
• Calculate breakdown voltage
• Graph data (Paschen curve)

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Closure

• Looking at your Paschen curve, what do you see
  that may be significant?
• If you were funding a plasma experiment (you pay
  salaries, utilities, and for equipment) at what
  pressure-distance product would you want to
  produce plasma? Why?

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Independent Practice

• Look at the following video
• http//www.youtube.com/watch?vos2xs6S4i-g
• Explain why this phenomena occurs and draw a
  representation of what is in the bulb before and
  after the bulb is illuminated. Label all parts
  in both of your drawings.
• In your journal, describe how plasma affects your
  life today and how you think plasma will affect
  your life in the future. Why do you think it is
  important to study efficiency in creating plasma?
  

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Other considerations

• Materials Needed
• 2kV Power source
• Glass tube
• Parallel plates
• Wires
• 5000O Resistor
• Vacuum pump
• Digital multimeter
• tubing

• Time Needed 2 hours
• First day Pre-lab
• Second day - Gather data
• Third day Graph data and
  discuss results

• New Jersey State Standards
• 5.7 (Physics)
• A. 4, 5, 6
• B. 1, 2

• Classroom Management
• Safety - vacuum pump and power supply
• Monitoring groups table to table

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Other considerations

• Assessment
• Lab practical
• Have each student adjust valve to specific
  pressure and measure plate distance to determine
  plasma breakdown voltage.

• Assessment
• Exam Questions
• Paschen curve will be given for mercury
• Plasma was created at 100mTorr at 2.5cm. What
  was the breakdown voltage?
• Paschen curve will be given for argon
• We are creating plasma at 300mTorr at 15cm. Is
  this the most efficient way to create plasma?
  Explain your reasoning.

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Acknowledgements
We would like to thank Jose Lopez (PARSE
Institute), Jim Clayton (PARSE Institute), and
Andrew Zwicker (PPPL), for their collaborative
efforts in making this experience possible.
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PRETTY PLASMA!
Questions?
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Lab Activity Procedure