CONFIDENTIAL

General Fusion update

Michel Laberge

ARPAE- 2017

2

Spherical Shape

3

Magnetic Field During Compression

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Shaft Current And Formation Current

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X-Ray and Density

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• PCS15 will compress earlier when the plasma is hotter• Better temperature diagnostic, x-ray, ion Doppler, neutrons• Unfortunately the current profile is hollow at these earlier time• Plasma might go unstable• Shoot in September, if it rains (forest fire hazard too high right

now!!)

Next shot

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• Peter Turchi and others convinced us that we can’t exceed 100T at peak compression due to wall vaporization

• Start with larger flux conserver radius (20 cm to1.5 m), lower density (1e17 cm-3 to 3e14 cm-3), hotter (100 eV to 400 eV) plasma

• Slower compression time (100 µs to 4 ms) less compression ratio (10 to 7:1)

• Rotation stabilization of RT instability (1000 rpm)• Lower peak field (700 T to 100 T) and density (1e20 cm-3 to

1e17 cm-3)• Much more LINUS like

Change to slower liner, less peak energy density

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Fusion Technology Comparison

1.00E+06

1.00E+09

1.00E+12

1.00E+15

1.00E+13 1.00E+16 1.00E+19 1.00E+22 1.00E+251.00E+02

1.00E+05

1.00E+08

1.00E+11

Driver PowerPlasma Energy

kJ

MJ

GJ

MW

GW

TW

$ Co

st o

f Con

finem

ent

$ Co

st o

f Driv

er

NIF

GF

Plasma Density (cm-3)

Magnetic Field (Tesla)

30 1.00E+3 3.00E+4 1.00E+6

Normal Super-

conductor HTC Max DCMax Flux

Compression

ITER

1

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• We achieved much better confinement with spherical tokamak• Lack of toroidal field in edge of spheromak produce stochastic

field in the edge, fast electrons escape, poor confinement• Did not try FRC but I suspect the lack of toroidal there to also

cause poor confinement• Better bet to compress the pretty well known spherical

tokamak• Need central shaft, engineering pain but easier than

confinement pain• To compress spheromak or FRC need faster compression

because of poor confinement

Initial plasma spherical tokamak

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General Fusion’s Solution

1. Inject Plasma Fuel 2. Compress Plasma Fuelv v

3. Extract Energyv

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• Designing a ~1.5 m radius liquid lithium plasma formation and compression machine

• ~1MA of plasma current spherical tokamak starting plasma (MAST/NSTX class)

• Sub-breakeven but high performance (10 keV at 7e16 cm-3)• Still costing the machine but estimate ~100 M$• 3-5 years project• Will try to raise this money towards the end of this year

Next step