sun - chalmers · fusion can be placed into national energy supply strategies • with fusion, we...

1

Chalmers energy conference 2012

Magnetic Confinement Fusion-Status and Challenges

F. Wagner Max-Planck-Institute for Plasma Physics, Greifswald Germany, EURATOM Association

RLPAT St. Petersburg Polytechnic University

Sun Fusion supplies the universe with energy

In the core of the sun: 15 Mill °C

Matter: in the plasma state

Energy-mass equivalence: E=mc2

4 Mill tons of mass/sec to energy

Fusion energy maintains fusion conditions: → self-sustained burn

2

Energy 2050

2

Sun confinement by gravity

ITER tokamak magnetic confinement

4p He4 + energy D + T He4 + n + energy

From the sun to the 1st fusion reactor

3

Energy 2050

3





4

Energy 2050

4





5


Fusion basics

D+T He4+n+ 17.6 MeV (1 g fusion fuel = 10 tons coal)

n + 7Li 4He + T + n‘ - 2.5 MeV

T from breeding reaction:

Technical fusion: hydrogen istopes deuterium (D) and tritium (T)

He (α-particle; Eα = 3.5 MeV) provides the internal heating; maintains the power producing plasma state. When cooled down: ash → ash removal n carries its energy (En = 14.1 MeV) to the outside.

6


Pro: D from sea water Li from earth crust → inexhaustable energy source equal distribution of fuel on earth no CO2 poduction no uncontrollable power excursions no critical afterheat no radio-active fusion products Con: (1) tritium is radio-active

BUT: the production of tritium is in situ (2) neutrons activate structural materials

BUT: radio-active by-products are well confined

pros and cons of fusion energy

0.08 g D und 0.2 g Li put in a fusion reactor

would supply a family of 4 with electricity for a year

Source: FZJ

Their decay time is about 100 years

7


The task • Confine a hot, high-pressure D-T plasma

• Heat it to high temperatures externally till inner α-particle heating takes over (→ self-sustained burn)

• Provide plasma equilibrium, stability and good confinement

• Exhaust the He ash and maintain high plasma purity

• Breed tritium within a “Lithium-blanket” via the fusion neutrons

• Remove the neutron-heat deposited into the blanket

• Produce electricity by standard steam techniques

• Realisation: •Inertial confinement (use e.g.lasers to compress pellets)

•Magnetic confinement

8

Energy 2050

-∇p

gravity

Magnetic confinement

9

Energy 2050

-∇p

gravity

Magnetic confinement sphere torus

10

Energy 2050

-∇p

gravity

Magnetic confinement

-∇p Magnetic force

11

Energy 2050

Tokamak (1951 Sacharov und Tamm) тороидальная камера в магнитных катушках

„toroidal chamber within magnetic coils“

Tokamak: The most advanced system

Plasmaring with magnetic field

induced like in a transformer

Strong current inside the plasma

12

Energy 2050

The stellarator

13


13

JET: the largest tokamak

14


14

Devices of the Asian fusion programme KSTAR - Korea

SST-1 India

JT-60 SA Japan

EAST- China

15


Wendelstein 7-X, Greifswald

16


16

16.1 MW fusion

power from JET H

200 Mill °C in

the core of JET

Status of Fusion Research

17


Fusi

on tr

iple

pro

duct

nT i

τE (1

020 m

-3 s

ec k

eV)

Central ion temperature Ti (keV)

Status of Fusion Research

After 50 years of fusion research

there is no evidence for a fundamental obstacle in

the basic physics

But, of course, still many problems

have to be overcome

18


Fusion power 500 MW

Power amplification Q=10

External heating 70 MW

Pulse lenght > 8 Min.

Plasma current 15 MA

Plasma volume 840 m3

Plasma energy 350 MJ

Magnetic field 6 T (12 T)

Energy of the field 10 GJ

The first fusion reactor: ITER

Size

International partnership China, Europe, India, Japan,

Korea, Russia, USA

19

Energy 2050

Why so large ?

centre

20

Energy 2050

Why so large ?

centre

21

Energy 2050

Why so large ?

centre

22

Energy 2050

Why so large ?

centre

23


Physics: •Confine a plasma magnetically with 1000 m3 volume

•Maintain the plasma stable at 2-4 bar pressure and 150 Mill °C in core

•With 15 MA current running in a fluid (tokamak)

•Find methods to maintain the plasma current steady-state (tokamak)

•Tame plasma turbulence to get the necessary confinement time Technology: •Build a system with 200 Mill K in the plasma core and 4K about 2 m away

•Build magnetic system at 6 T (max. Field 12 T) with 50 GJ energy

•Handle n-fluxes of 2 MW/m2 leading to 100 dpa

•Handle α-particle power of 10 MW/m2 onto divertor targets

•Develop low activation material

•Develop T breeding technology

•Provide high availability of a complex system

Challenges for the fusion programme

24


Does fusion come too late ?

2005 2010 2015 2020 2025 2030 2035 2040 2045 2050

ITER

Pla

sma

phys

ics

Inst

alla

toin

s Te

chno

logy

Tokamak physics programme Commercial availability

Stellarator development

ITER- Technology

Electricity production

DEMO

DEMO Technology

Decision point

„road map“ to a fusion power station

JET

IFMIF, 14 MeV neutron source

25


Change in technology

from red to blue

Increase in

world population

Increase of CO2

Increase in energy

consumption

Oil – peak

now 2050

Blue: RE, fission with breeder fusion The 1st half of this century will experience dynamic developments There are many uncertainties

→ keep all options open

Does fusion come too late ?

26


Final comment • Research into high temperature plasmas is an intellectually rewarding field

• Fusion has a tremendous potential facing the future uncertainties - the risks of fission, storage of RE – the fusion development has to be accelerated

• There is a clear road-map to commertialize fusion (of course, there is still no guarantee of final success)

• ITER will answer open physics questions related to burning plasmas

• W7-X will demonstrate the quality expected from stellarator optimisation

• ITER, IFMIF, DEMO: The programme will move away from plasma science more toward technology orientation

• After the ITER physics and technology programme - if successful – fusion can be placed into national energy supply strategies

• With fusion, we hand over to future generations a clean, safe and - in our expectations - economic power source

sun - chalmers · fusion can be placed into national energy supply strategies • with fusion, we...

Documents