Plasma & Fusion on Earth: merging age-old natural phenomena into your present and future

Shannon Greco, PPPL

sgreco.pppl.gov

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Rick Lee, General Atomics

rick.lee@gat.com

AKA: Plasma 101

https://linktr.ee/PPPLconnect

Presented APS/DPP 2024 Teachers Day

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Why are We Interested in Plasmas?

• Fusion Energy use in Electrical Energy Production
• Plasma is the state of matter in fusion reactions. Fusion is a potential source of relatively safe & clean, sustainable & abundant electrical energy.
• Astrophysics
• Understanding plasmas helps us to better understand stellar evolution. Locally, we can better comprehend the interactions of solar wind particles and Earth’s magnetic field.
• Upper atmospheric dynamics
• The ionosphere is a plasma. Radio waves reflect off the ionosphere.
• Plasma Applications
• Plasmas can be used to build lights, computer chips, to clean up toxic waste, and to drive space craft.

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Plasma is Called the 4^th State of Matter and it is the 1^st Step Towards Fusion

• A plasma is an ionized gas (1 or more e^- have been removed from, or added to, a neutral atom) of many particles.

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• Plasma is called the “4th state of matter.” Why?

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• About 99% of the visible mass of the universe is in a plasma state.
• However, this is relatively little of the overall matter of the universe – about 96% of the universe is dark energy + dark matter!

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Van de Graaff Generator – A Polarized (Electrostatic) High Voltage Experience

Study.com

fishersci.com

Robert Jemison Van de Graaff (December 20, 1901 – January 16, 1967) was an American physicist, noted for his design and construction of high-voltage Van de Graaff generators. He spent most of his career in the Massachusetts Institute of Technology (MIT). -From Wikipedia

A Van de Graaff generator is an electrostatic generator which uses a moving belt to accumulate electric charge on a hollow metal globe on the top of an insulated column, creating very high electric potentials. It produces very high voltage direct current (DC) electricity at low current levels.

- From Wikipedia.

When a person is in contact with the positively charged globe, they become charged as well. Since the charge is the same everywhere, low mass materials, such as strands of hair, repel each other and provide an interesting fan shape.

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Where can plasmas be found?

• Examples of plasmas on Earth:
• Lightning
• Neon and Fluorescent Lights
• Laboratory Experiments
• Examples of astrophysical plasmas:
• The sun and the solar wind
• Stars, interstellar medium

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Auroras are particularly impressive displays of light emitted from excited atoms and plasma seen on (and from) Earth

Auroras are the light emitted by excited and ionized molecules of the atmosphere of a large body which also has a magnetic field.

The excitation and ionization and consequent emission occur from collisions of atmospheric molecules with charged particles originating in the sun and other stars which have traveled huge distances and have become trapped in a planet’s magnetic field structure, such as happens on earth.

In addition to stellar-origin auroras, Jupiter’s very strong magnetic field pulls particles from its highly volcanic moon, Io, into its atmosphere where X-ray and UV auroras have been observed by the Juno spacecraft. Nasa photo

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Electric and Magnetic Fields Influence the Motion of Charged Particles – Natural Phenomena

a. Electron beam apparatus (a)

i. evacuated bulb with some He or Ne gas

ii. e- beam is generated by heating a metal oxide and accelerating emitted electrons

iii. electric field, E, exists between small plates

iv. User may use emagnets or permanent magnets

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b. E field force: F_E = qE (q is charge)

Causes straight-line motion (b)

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c. Magnetic fields have an effect on moving & charged particles

F_B = q(v x B) causes circular motion

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d. F_E,B = q(E + v x B).

What type of motion results?

(Line + circle = spiral ! )

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Plasma Characteristics Can Be Measured Using Diagnostics Based on Various Phenomena

• Emitted light
• spectroscopy based on wave interference can measure temperature, ionization state, and impurity content
• Presence of charge
• Magnetic pickup coils measure a plasma’s magnetic field
• Voltage-biased probes (Langmuir) measure e^- temperature & density
• Thomson scattering of light from plasma electrons (temp & density)
• Plus many other diagnostics

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Why is Fusion Important to You?

Why is Fusion Important to You?

Hoekom is Fusion vir jou belangrik?

Pse është Fusion i rëndësishëm për ju?

No ke aha he mea nui ka Fusion iā ʻoe?

Dlaczego Fuzja jest dla Ciebie ważna?

Почему фьюжн важен для вас?

Anata ni totte fu~yūjon ga jūyōna no wa nazedesu ka?

Fusion-i dangsin-ege jung-yohan iyuneun mueos-ibnikka?

¿Por qué es importante la fusión para usted?

Tại sao Fusion quan trọng với bạn?

Pourquoi la fusion est-elle importante pour vous ?

SPACE TELESCOPE SCIENCE INSTITUTE

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19

Nuclear fusion – We Would Not be Here Without it!

Basic idea…..

Outcome = different nucleus plus energy

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Element formation has many pathways. The Periodic Table is a Self-portrait of You and Me!

https://en.m.wikipedia.org/wiki/File:Nucleosynthesis_periodic_table.svg

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Humans Have Learned to Utilize Wires, Cables, and Gizmos to Transfer Energy via ‘Electricity’

The phrase ‘Electrical energy’ refers to methods used to transfer energy from one location to another using conductive materials.

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Why is electrical energy use so prevalent? We understand how to safely transfer, contain, utilize better than most other methods.

https://www.theatlantic.com/

quora.com

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The ultimate goal of fusion research is…

To use energy from the process of fusion to find pathways to:

A. heat water

B. make steam

C. turn a turbine (propeller set)

D. turn an electrical generator

E. make electricity

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Advantages & Disadvantages of Fusion as an Energy Producer

Advantages

No greenhouse gas output

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Fuel resource will last many years

Deuterium, a hydrogen isotope, is found in all water and tritium is a byproduct of the (Li) heat-transfer process and can be separated for use

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Minimal radiation issues –

there will be local activation of structural materials which will preclude humans from entering the reactor housing. Instead, robotic tools will be used. Reactor materials may be activated for 100s of years. This is less time than the 4.5 BY half-life of fission materials.

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• Works independently of other power sources

Disadvantages

Fusion is a difficult science & technological challenge; some have said it is the most ambitious and difficult undertaking ever attempted by humankind.

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Relies heavily on advanced material science

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Requires a lot of electrical energy for magnets

Limited helium supply on Earth - He is used to cool magnets (superconducting) and as a cryo-pumping resource – while helium is not a fuel, could it be a limiting resource?

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Protons, Isotopes, Neutrons, and Binding Energies are the Players in Laboratory Nuclear Fusion Reactions

The Players

The hydrogen isotopes

The helium isotopes

NOTE: The Sun uses hydrogen as its fuel and fusion occurs through 2 major processes: “proton-proton” and CNO cycle.

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Mass ‘goes’ into Energy in Fusion Reactions: D-T Reaction As A Power Plant Example

The above reaction will be typical of fusion power plants. Fusion reactions in nature use H and many other low-mass atoms found in the periodic table.

Although we say the process “turns mass into energy,” a more understandable way to put it is: the origin of the released energy is the rearrangement of nuclear bonds with a consequent loss of mass.

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Much energy is needed to overcome the repelling forces of the reactant ions. High temperature (≈ 10 -100⁺ million K) conditions are required.

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High energy neutron will be used in a multi-step process to heat fluid (water) to gas to turn turbine, while energy from alpha particle (He²⁺) is used to sustain reaction

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The Magnetic Confinement Fusion Reactor as a Power Source – a Tokamak*

What are the steps to produce usable energy?

• Make a plasma---ionize the gas atoms
• Hold on to the plasma---use a magnetic field
• Heat the plasma---use particle beams and electromagnetic energy (RF, microwave)
• Harness the energy---use a series of heat exchangers involving liquid metals and other fluids
• Exchange the energy released by the fusion rxns for electrical energy
• Provide electricity as the energy conveyance method to industries and households.

*tokamak from the Russian: toroidalʹnaya kamera s magnitnym polem ‘toroidal chamber with magnetic field’

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Many Fusion Approaches are Being Developed Throughout the World

ICF & Laser Fusion

Australia

France

Germany

Japan

United Kingdom

United States of America

Table 4, IAEA 2022

Stellerators & Heliotrons

China

Costa Rica

France

Germany

Japan

Spain

Ukraine

United States of America

Table 3, IAEA 2022

Tokamaks

Brazil

Canada

China

Costa Rica

Czech Republic

Denmark Egypt

France

Germany

India

Islamic Republic of Iran

Italy

Japan

Kazakhstan Libya

Pakistan

Portugal

Republic of Korea

Russian Federation

Spain

Switzerland

Thailand

United Kingdom

United States of America

Fusion

Research

From: World Survey of Fusion Devices 2022, International Atomic Energy Agency

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Inside and Outside DIII-D… an Industrial-Scale Experiment

Inside DIII-D. It began operating in 1986. Annual upgrades keeps it state of the art.

Outside DIII-D, showing mechanical eng systems such as structural, fluids, vacuum, diagnostics, wiring & optical fibers

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The next step for Publicly funded Fusion : ITER - “The Way” is being built now in Southern France (see ITER.org)

- International

- Large scale tokamak design

- Produce fusion energy (500 MW)

- But, no electricity production

- One of humankind’s biggest science projects

GA is making central

solenoid

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ITER’s Timeline Has Been Fluid/ Competition on the Rise

Early estimates had ITER construction mostly completed and ITER operational by 2020.

• Later estimates extended this date until 2032.
• Start going down the rabbit hole here:

https://www.youtube.com/watch?v=MP2aV26X-70

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• DEMO projects, designed to make electricity, may start popping up in 2040s (?)

Many (42) nuclear fusion startups…. including

Helion Energy General Fusion

Tokamak Energy First Light Fusion

Avalanche Fusion HB11

Kyoto Engineering

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https://tracxn.com/d/trending-themes/startups-in-nuclear-fusion

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Public Engagement Opportunities Abound

https://linktr.ee/PPPLconnect

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Parting Thoughts -

• Dinosaurs roamed the earth for more than 100 M years without requiring a drop of fossil fuel! Modern humans have existed for ≈ 0.2 M years.

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• Human population hit 1 x 10⁹ soon after 1800 and may reach 11 x 10⁹ by 2100.

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• How will humans survive and thrive? What energy, food, water resources will exist?

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Nature Has Provided 2 Knobs to Exercise to control Plasmas: Electric and Magnetic Field Vectors

• Electric Fields, E(N/m), where E represents the magnitude and direction of the electric field vector. The direction of E, by convention, or, agreement among the scientific community, originates at a + source.

F = qE leads to ‘pushing’ or ‘pulling’ charges in a linear direction.

• Magnitude of force on charge q is directly proportional to electric field E strength.
• Direction of force is in same direction as E field direction (+ 🡪 -)

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• Magnetic fields

F = q v X B = qvB x sin θ in a direction perp to v and B

θ is angle between v and B

dir is direction perpendicular to v and B

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Plasma particles have mass and charge…. Methods for confinement – or, how do you hold on to something that is > 5,000 K?

• Hot plasmas are confined with gravitational fields in stars.

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• In fusion energy experiments magnetic fields are used to confine hot plasma, and inertial confinement uses an imploding surface.

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Matter exists in a wide temperature range: a few examples

100,000,000 D+T & D+D nuclei fuse in tokamak

16,000,000 center of sun (H fusion)

100,000 lightning (no fusion, but ionized O, N)

10,000 fluorescent light (Ar & Hg ions)

6,000 observed surface of sun

3,400 W (tungsten) melts

1,500 Fe (iron) melts

100 water boils at 1 atm

23 room temp

0 water ice

Dry Ice (CO₂) -78

LN₂ -196

LHe -269

Abs. Zero -273

˚C

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Joint European Torus: outside

Person

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Inside the Joint European Torus - JET the largest Tokamak

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One Method of Magnetic Confinement uses the Tokamak Device

• Russian: toroidalʹnaya kamera s magnitnym polem ‘toroidal chamber with magnetic field’
• comes from a Russian acronym that translates to "toroidal chamber with magnetic coils": 
• The term was coined in 1957 by Igor Golovin, a student of academician Igor Kurchatov. The original pronunciation was "tokamag" ("токамаг"), but Natan Yavlinsky, the author of the first toroidal system, suggested replacing "-mag" with "-mak" for euphony. 
• A tokamak is a device used in nuclear fusion research to confine plasma magnetically. It's made up of a complex system of magnetic fields that keep the plasma of reactive charged particles in a hollow, doughnut-shaped container. 
• Tokamaks began operating in Russia in the 1950s.
• Since then, tokamaks have been used to achieve the greatest advances in thermonuclear fusion research. 
• �

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Review of Simple Atomic States Yields Interesting Observable Possibilities

Ground state

(neutral)

Excited state

(neutral)

Ionized state

(plasma)

e^- drops to a lower energy level and light, hν, is emitted

Planck’s constant, h = 6.63e-34 Js.

ν is frequency in s^-1, or Hertz.

Once, e^- are excited or ionized, they typically lose that added energy by returning to a lower state, either on their parent atom or another ion, and emit visible light. There is a constant repetition of absorption and emission of energy.*

*unless the input energy is high enough to keep free e- from returning to a positive ion.

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In addition to what’s highlighted at right, tokamak plasmas are heated by neutral particle beams and radio-frequency & microwave electromagnetic waves.

DIII-D is Similar in Construction to Other Tokamaks

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Do we need new sources of energy?

The world’s population is increasing and demands more electricity (water pumps, refrigeration, other large-scale industrial uses)

The cost of mining coal and oil for burning will eventually be prohibitive

- reduced supply

- there are better uses for these resources than burning)

Water, wind, & solar do not satisfy needs in all locations

Fission may be supply-limited, and has weapons concerns, but is a good intermediary source.

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DIII-D is the largest magnetic confinement fusion device in the U.S. It is located in San Diego, CA.

• DIII-D, a Mid-sized Tokamak, is Operated by General Atomics for the US Department of Energy

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