FusionFusionCelestial to EarthboundCelestial to Earthbound

A ComparisonA Comparison

1 gallon of seawater=300 gallons of gasoline1 gallon of seawater=300 gallons of gasoline 82,459,000 barrels per day in 2005 -> 82,459,000 barrels per day in 2005 ->

1,583,212,800 gallons of gasoline1,583,212,800 gallons of gasoline 5,277,376 gallons of ocean water burned in a 5,277,376 gallons of ocean water burned in a

fusion reactor= 1,583,212,800 gallons of fusion reactor= 1,583,212,800 gallons of gasolinegasoline

5,277,376 gallons of ocean water=1.5E-12% 5,277,376 gallons of ocean water=1.5E-12% of the total volume of the oceanof the total volume of the ocean

Only .015% of naturally occurring hydrogen Only .015% of naturally occurring hydrogen is deuteriumis deuterium

How Does Fusion How Does Fusion Occur?Occur? Two lighter nuclei combine to Two lighter nuclei combine to

form a heavier nucleus coupled form a heavier nucleus coupled with a release of energywith a release of energy

Coulomb BarrierCoulomb Barrier– HeatHeat

Fuel ConfinementFuel Confinement Self Sustaining?Self Sustaining?

– Lawson CriteriaLawson Criteria

The SunThe Sun

Proton-Proton chainProton-Proton chain– BeginningsBeginnings

11H + H + 11H → H → 22H + H + ee++ + + ννee 22H + H + 11H → H → 33He + He + γγ

– pp1pp1 33He +He +33He → He → 44He + He + 11H + H + 11HH

– pp2pp2 33He + 4He→He + 4He→77BeBe + + γγ             77Be + e−→Be + e−→77LiLi + + νeνe               77Li + Li + 11H→H→44He + He + 44HeHe

– pp3pp3 33He + He + 44He→He→77Be + Be + γγ             77Be + Be + 11H→H→88BB + γ   + γ   88B→B→88Be + eBe + e++ + + νeνe               88Be↔Be↔44He + He + 44HeHe

The Sun (cont’d)The Sun (cont’d)

Carbon-Nitrogen-Carbon-Nitrogen-Oxygen chainOxygen chain– 1212C + C + 11H→H→1313N + γN + γ– 1313N→N→1313C + e+ + νeC + e+ + νe– 1313C + C + 11H→H→1414N + γN + γ– 1414N + N + 11H→H→1515O O – 1515O→O→1515N + e+ + νeN + e+ + νe– 1515N + N + 11H→H→1212C + C + 44HeHe

Earthbound?Earthbound?

Can’t use gravitational forceCan’t use gravitational force– Must use electromagnetic forceMust use electromagnetic force

Magnetic confinementMagnetic confinement Limited in reaction choiceLimited in reaction choice

– ExothermicExothermic– Low Z nucleiLow Z nuclei

Ignition EnergyIgnition Energy– D-T reaction=100 million degrees D-T reaction=100 million degrees

Celsius Celsius

The ReactionsThe Reactions

(1)D+T→ (1)D+T→ 44He(3.5 MeV)+ n(14.1 MeV) He(3.5 MeV)+ n(14.1 MeV)  (2i)D+D→ T(1.01 MeV)+ p(3.02 MeV)    (2i)D+D→ T(1.01 MeV)+ p(3.02 MeV)    50%50% (2ii)   → (2ii)   → 33He(0.82 MeV)+ n(2.45 MeV)    He(0.82 MeV)+ n(2.45 MeV)    50%50% (3)D+(3)D+33He→ He→ 44He(3.6 MeV)+ p(14.7 MeV)He(3.6 MeV)+ p(14.7 MeV) (4)T+T→ (4)T+T→ 44He +2 n+ 11.3 MeVHe +2 n+ 11.3 MeV (5)(5)33He+He+33He→ He→ 44He +2 p+ 12.9 MeVHe +2 p+ 12.9 MeV (6i)(6i)33He+T→ He+T→ 44He + p +n+ 12.1 MeV He + p +n+ 12.1 MeV 51%51% (6ii)   → (6ii)   → 44He(4.8 MeV)+ D(9.5 MeV)    He(4.8 MeV)+ D(9.5 MeV)    43%43% (6iii)   → (6iii)   → 44He(0.5 MeV)+ n(1.9 MeV)+p(11.9 MeV) He(0.5 MeV)+ n(1.9 MeV)+p(11.9 MeV) 6%6% (7)D+(7)D+66Li→2 Li→2 44He+ 22.4 MeVHe+ 22.4 MeV (8)p+(8)p+66Li→ Li→ 44He(1.7 MeV)+ 3He(2.3 MeV)He(1.7 MeV)+ 3He(2.3 MeV) (9)3He+(9)3He+66Li→2 Li→2 44He + p+ 16.9 MeVHe + p+ 16.9 MeV

First StepsFirst Steps

Hydrogen BombHydrogen Bomb Radio-frequency heatingRadio-frequency heating Linear ConfinementLinear Confinement

– Pinch effectPinch effect Magnetic MirrorsMagnetic Mirrors ToroidToroid

– StellaratorStellarator

StellaratorStellarator

ProblemsProblems

Plasma InstabilityPlasma Instability Heat LossHeat Loss

TokamakTokamak

Large toroid that produces a Large toroid that produces a toroidal magnetic fieldtoroidal magnetic field

Charged plasma also creates Charged plasma also creates magnetic fieldmagnetic field

Large external shaping magnetsLarge external shaping magnets Name derived from Russian: Name derived from Russian:

toroidalnaya kamera magnitnaya toroidalnaya kamera magnitnaya katushka katushka

Tokamak (cont’d)Tokamak (cont’d)

Tokamak (cont’d)Tokamak (cont’d)

Tokamak (cont’d)Tokamak (cont’d)

The Big ThreeThe Big Three

TFTR (tokamak fusion test reactor TFTR (tokamak fusion test reactor located at Princeton University) located at Princeton University)

JET (joint European torus, located JET (joint European torus, located in Culham, UK as part of a in Culham, UK as part of a European collaboration)European collaboration)

JT-60 (located in Japan)JT-60 (located in Japan)

ResultsResults

JET reactor produces 16MW of JET reactor produces 16MW of fusion energyfusion energy

TFTR and JT-60 produce around TFTR and JT-60 produce around 10.7 MW of fusion energy10.7 MW of fusion energy

Q values of 0.6-0.9Q values of 0.6-0.9

The FutureThe Future

ITER (international thermonuclear ITER (international thermonuclear experiment reactor)experiment reactor)

GoalsGoals– 400MW fusion energy400MW fusion energy– Q value of around 10Q value of around 10

ConsiderationsConsiderations

SafetySafety– Amount of fuel in reactorAmount of fuel in reactor– Reaction sustainabilityReaction sustainability

WasteWaste FuelFuel

SourcesSources

1)http://www.bp.com1)http://www.bp.com 2)Fowler, T. K. 2)Fowler, T. K. The Fusion Quest, The Fusion Quest, The Johns Hopkins The Johns Hopkins

University Press: Baltimore and London, 1997University Press: Baltimore and London, 1997 3)Braams, C.M.; Stott, P.E. 3)Braams, C.M.; Stott, P.E. Nuclear Fusion: Half a Nuclear Fusion: Half a

Century of Magnetic Confinement Fusion ResearchCentury of Magnetic Confinement Fusion Research; ; Institute of Physics Publishing: Bristol and Institute of Physics Publishing: Bristol and Philadelphia, 2002Philadelphia, 2002

4)http://www.jet.efda.org/pages/focus/006heating/7c-4)http://www.jet.efda.org/pages/focus/006heating/7c-t.jpgt.jpg

5)http://en.wikipedia.org/wiki/ITER5)http://en.wikipedia.org/wiki/ITER 6)http://www.lateralscience.co.uk/latscipics/6)http://www.lateralscience.co.uk/latscipics/

stellarator.jpgstellarator.jpg