Plasma Fusion Energy Technology. S Lee 1,2,3 & S H Saw 2,1 1 Institute for Plasma Focus Studies 2 INTI University College, Malaysia 3 Nanyang Technological University/NIE Singapore. International Conference on Recent and Emerging Advanced Technologies in Engineering
S Lee1,2,3 & S H Saw2,1
1Institute for Plasma Focus Studies
2INTI University College, Malaysia
3Nanyang Technological University/NIE Singapore
International Conference on Recent and Emerging Advanced Technologies in Engineering
iCREATE 2009, 23 & 24 November 2009, Kuala Lumpur Malaysia
Whilst above the white stars quiver
With Fusion Energy burning bright
Matter heated to high temperatures becomes a Plasma
Four States of Matter
-Cold plasmas: several eV’s; (1eV~104K)
-Hot plasmas: keV’s ; (1keV~107K)
A NEW LIMITLESS SOURCE OF ENERGY
Fossil, Hydro, fission
A new source of abundant (limitless) energy is needed for the continued progress of human civilization.
Mankind now stands at a dividing point in human history:
Human civilization cannot continue to flourish.
Only 1 good possibility:
Fusion Energy from Plasma Reactors
The hotter the plasma is heated, the more energetic are the collisions
If a Collision is sufficiently energetic, nuclear fusion will occur
50 cups water
n=1020 m-3, confined t=10s (low density, long-lived plasma) or :
n=1031 m-3, confined 10-10s(super-high density, pulsed plasma)
Long-lived low-density Confinement
Pulsed High Density Confinement
Magnetic Yoke to induce Plasma Current consuming energy at 2/3 US 1985 per capita rate
Field Coils to Produce suitable Magnetic Field Configuration
Inside JET consuming energy at 2/3 US 1985 per capita rate
scaling law: t~Ipa Rb ag Bl
indices a,b,g,l all positive
To achieve sufficient value of ntT requires:
scaling of present generation of Tokamaks upwards in terms of:
Ip, R, ‘a’ and B.
Needs x10 to reach ITER
Needs another 2x to reach Power Plant
Systems Energy-ITER: Magnets: Ten thousand tons of magnets: 18 extremely powerful superconducting Toroidal Field & 6 Poloidal Field coils;a Central Solenoid, and a set of Correction coils: magnetically confine, shape and control the plasma inside the toroidal chamber
Vacuum & Cryogenics Energy-ITER Vacuum vessel: Volume=1400 m3Surrounding Cryostat vacuum jacket (not shown): Volume=8500 m3; Total vacuum volume~10,000 m3Largest vacuum volumes ever built; use mechanical & cryogenic pumpsVacuum vessel is double-walled with water flowing between the walls
provides shielding to the Vessel and the superconducting Magnets from the heat and neutron fluxes of the fusion reaction.
The neutrons are slowed down in the blanket, their K.E. is transformed into heat energy and collected by coolants. This energy will be used for electrical power production. One of the most critical and technically challenging components:
together with the divertor it directly faces the hot plasma.
Breeding modules will be used to test materials for Tritium Breeding. A future fusion power plant will be required to breed all of its own Tritium.
The Divertor is situated along the bottom of the Vacuum Vessel,
its function is to extract heat and Helium ash — the products of the fusion reaction — and other impurities from the plasma, in effect acting like a giant exhaust pipe.
It will comprise two main parts: a supporting structure made primarily from stainless steel and the plasma facing component, weighing about 700 tons. The plasma facing component will be made of Tungsten, a high-refractory material.
BLANKET features include the following:: covers the interior surfaces of the Vacuum Vessel, provides shielding to the vessel & the superconducting magnets from the heat and neutron flux of the fusion reactionModular wall: 440 segments each 1x1.5m weighing 5 tons ; surface facing the plasma is plated with Berylium
Divertor: Is placed at bottom of the vacuum chamber To remove waste gases from the D-T reaction; and to recover the heat from this waste gas. The surface temperature of the divertor goes up to 3000 C; surface cover will be composite carbon or tungsten
An extensive diagnostic system (50 individual systems) installed to provide t measurements: control, evaluate & optimize plasma performance. Include measurements of temperature, density, impurity concentration, and particle &energy confinement times.
Cryostat: Large stainless steel structure surrounding the vacuum vessel & superconducting magnets, providing a supercooled vacuum jacket. Double wall, space between filled with pressurised He, as a thermal barrier.This is a huge structure: 31m tall x 37m wide; with openings for access to vacuum chamber, cooling systems, magnets, blanket and divertor
ten times hotter than the Sun’s core- & be sustained in a controlled way in order to extract energy.
The plasma in the vacuum vessel is produced and heated by a current induced by transformer action using a central solenoid (inner poloidal) coil, as primary of a transformer; the toroidal plasma current forms the secondary of the transformer
Then 3 sources of external heating are used to provide the input heating power of 50 MW required to bring the plasma to the necessary temperature.
1. neutral beam injection
2. ion cyclotron heating &
3. electron cyclotron heating.
A "burning plasma" is achieved –in which the energy of the Helium from the fusion reaction is enough to maintain the plasma temperature. The external heating is then switched off. The plasma fusion burn continues.
First plasma planned 2018
First D-T planned 2022
ITER : to demonstrate: possible to produce commercial energy from fusion.Q= ratio of fusion power to input power.
Q ≥ 10 represents the scientific goal of ITER :
to deliver 10x the power it consumes.
From 50 MW input power to 500 MW of fusion power - first fusion experiment to produce net energy.
Beyond ITER will be DEMO (early 2030’s), demonstration fusion power plant which will put fusion power into the grid as early as 2040
Smaller scale Fusion Experiments
HV (Norimatsu et al.)
30 mF, 15 kV
The Plasma Dynamics in Focus
Axial Accelaration Phase
Inverse Pinch Phase
2 Torr Neon
Current: 120 kA
2 million oC
Soft x-ray burst:
23 June 2009 - First test shot of INTI-PF
we need n of 1021 m-3-s.
n (m-3) (sec)
Tokamak 1021 1
Plasma focus 1027 10-6
Laser implosion 1031 10-10
For the PF the scaling needs to be pushed in a different direction using the consideration of a beam-target mechanism. This is what we are doing in the global scaling slide where Yn is found as a scaling of E0.
Global Scaling Law (Norimatsu et al.)Scaling deterioration observed in numerical experiments (small black crosses) compared to measurements on various machines (larger coloured crosses) Neutron ‘saturation’ is more accurately portrayed as a scaling deterioration-Conclusion of IPFS-INTI UC research
Axial Axial Ipeak
PF Z0 =(L0/C0)1/2 DR0 dominance
Small 100 mW7 mWZ0 ~V0/Z0
Large 1 mW7 mWDR0 ~V0/DR0
As E0 is increased by increasing C0, with voltage kept around tens of kV, Z0 continues to decrease and Ipeak tends towards asymptotic value of V0/DR0
I (consider just the outside mesh only)peak vs E0 from DR0 analysis compared to model simulation
Model simulation gives higher Ipeak due to a ‘current overshoot effect’ which lifts the value of Ipeak before the axial DR0 fully sets in
Ipeak vs E0 on log-log scale
Confirming that Ipeak scaling tends to saturate before 1 MJConfirming Ipeak saturation is due to constancy of DR0
IPFS-INTI UC Project: we have shown that: constancy of DR (consider just the outside mesh only)0 leads to current ‘saturation’ as E0 is increased by increasing C0. Tendency to saturate occurs before 1 MJ
From both numerical experiments as well as from accumulated laboratory data:
Hence the ‘saturation’ of Ipeak leads to ‘saturation’ of neutron yield Yn
Possible ways to improve Yn:
This latest research breakthrough by the IPFS-INTI UC team will enable the plasma focus to go to beyond saturation regimes. The plasma focus could then become a viable nuclear fusion energy scheme.