16-05-2010, 08:50 PM
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MAN MADE SUN
Presented by, Ananth.G
Krishnakumar.G
PSNA College of Engineering & Technology
Dindigul.
ABSTRACT
Today, we are in almost the peak of the technoz .Every nanosecond , the world exhibits a new technology .All these technologies lie under the roof for their operation .i.e. source of energy .With the development and rapid advancement in the technology ,we are now in demand for energy providers .so we going for many alternative ways of energy providers .
Of the most, sun is the mother for all energy providers .The base for this mother is intermolecular nuclear fusion reaction . .Today , we need a eco-friendly ,cheap ,renewable source of energy .The development of nuclear fusion as an energy source is one of the most complex scientific and technical tasks ever undertaken for non-military purposes and will still span several human generations. A fantastic progress has been obtained in magnetic fusion. Three generations of tokamaks with doubling of characteristic dimensions at each step led to a 10000 times higher value of the fusion triple product (density times temperature times confinement time) in the last 30 years. Since the start of controlled fusion research, a 10 million fold improvement in the fusion triple product has been obtained verging to reactor conditions.
The current power consumption in different parts of the world and an estimate of the future energy needs of the world shows that we need a high efficient source of energy . The present energy supplies and prospects, the possible consequences of a continued massive fossil fuel consumption, and the potential of non-fossil candidates for long-term energy production are outlined. An introduction to possible fusion processes in future fusion reactors is given. The inexhaustibility, safety, environmental and economic aspects of magnetic fusion energy are discussed.
What is artificial sun
In nuclear fusion, you get energy when two atoms join together to form one. In a fusion reactor, hydrogen atoms come together to form helium atoms, neutrons and vast amounts of energy. It's the same type of reaction that powers hydrogen bombs and the sun.
The sun emits strong lights that eradiate to Space and the massive energy comes from nuclear fusion. Just like the sun, future "artificial sun" can generate electricity and effectively solve the present energy crisis of mankind. Artificial sun is nothing but, the world's first complete Experimental Advanced Superconducting Tokomak (EAST) nuclear fusion device.
CONSTRUCTION:
¢ Vacuum vessel - holds the plasma and keeps the reaction chamber in a vacuum
¢ Neutral beam injector (ion cyclotron system) - injects particle beams from the accelerator into the plasma to help
heat the plasma to critical temperature
¢ Magnetic field coils (poloidal, toroidal) - super-conducting magnets that confine, shape and contain the plasma
using magnetic fields
¢ Transformers/Central solenoid - supply electricity to the magnetic field coils
¢ Cooling equipment (crostat, cryopump) - cool the magnets
¢ Blanket modules - made of lithium; absorb heat and high-energy neutrons from the fusion reaction
¢ Divertors - exhaust the helium products of the fusion reaction.
CONDITION:
1. The fusion reactor will heat a stream of deuterium and tritium fuel to form high-temperature plasma. It will squeeze the plasma so that fusion can take place.
The power needed to start the fusion reaction will be about 70 megawatts.
The fusion reaction will last from 300 to 500 seconds. (Eventually, there will be a sustained fusion reaction.)
2. The lithium blankets outside the plasma reaction chamber will absorb high-energy neutrons from the fusion
reaction to make more tritium fuel. The blankets will also get heated by the neutrons.
3. The heat will be transferred by a water-cooling loop to a heat exchanger to make steam.
4. The steam will drive electrical turbines to produce electricity.
5. The steam will be condensed back into water to absorb more heat from the reactor in the heat exchanger.
WORKING:
An artificial sun is basically a nuclear fusion reactor. The basic concept behind any fusion
reaction is to bring two or more atoms very close together, close enough that the strong nuclear force in their nuclei will pull them together into one larger atom. If two light nuclei fuse, they will generally form a single nucleus with a slightly smaller mass than the sum of their original masses.
The difference in mass is released as energy according to Einstein's mass-energy equivalence formula E = mc2. If the input atoms are sufficiently massive, the resulting fusion product will be heavier than the reactants, in which case the reaction requires an external source of energy. The dividing line between "light" and "heavy" is iron.
Fusion between the atoms is opposed by their shared electrical charge, specifically the net positive charge of the nuclei. In order to overcome this electrostatic force, or "coulomb's carrier", some external source of energy must be supplied.
The easiest way to do this is to heat the atoms, which has the side effect of stripping the electrons from the atoms and leaving them as bare nuclei. In most experiments the nuclei and electrons are left in a fluid known as a plasma.
The neutron flux expected in a commercial D-T fusion reactor is about 100 times that of current fission power reactors, posing problems for material design. Design of suitable materials is underway but their actual use in a reactor is not proposed until the generation after ITER.
SCHEMATIC REPRESENTATION OF ARTIFICIAL SUN
PLASMA:
Since plasmas are very good conductors, electric potentials play an important role. The potential as it exists on average in the space between charged particles, independent of the question of how it can be measured, is called the plasma potential or the space potential.
If an electrode is inserted into plasma, its potential will generally lie considerably below the plasma potential due to the development of a debye sheath .Due to the good electrical conductivity, the electric fields in plasmas tend to be very small. Plasma in which the magnetic field is strong enough to influence the motion of the charged particles is said to be magnetized.
In plasma, the electrons separate from the nucleus. Once the energy of heat releases the electrons from the atom, the electrons begin to move around quickly. The electrons are negatively charged, and they leave behind their positively charged nuclei. These positively charged nuclei are known as ions.When the fast-moving electrons collide with other electrons and ions, they release vast amounts of energy. This energy is what gives plasma its unique status and unbelievable cutting power.
ADVANTAGES:
© The power needed to start the fusion reaction will be about 70 megawatts, but the power yield from the reaction will be about 500 megawatts.
© Abundant fuel supply - Deuterium can be readily extracted from seawater, and excess tritium can be made in the fusion reactor itself from lithium, which is readily available in the Earth's crust. Uranium for fission is rare, and it must be mined and then enriched for use in reactors.
© Safe - The amounts of fuel used for fusion are small compared to fission reactors. This is
so that uncontrolled releases of energy do not occur. Most fusion reactors make less radiation than the natural background radiation we live with in our daily lives.
© Clean - No combustion occurs in nuclear power (fission or fusion), so there is no air pollution.
© Less nuclear waste - Fusion reactors will not produce high-level nuclear wastes like their fission counterparts, so disposal will be less
PRESENT SCENARIO:
Technicians are installing the full superconducting experimental Tokamak fusion device in Hefei, capital city of east China's Anhui Province on Feb 4, 2006.
Most parts of the device have been installed and experiments will start soon.
The full superconducting experimental Tokamak fusion device, nicknamed "artificial sun", can generate infinite, clean nuclear-fusion-based energy. It will be built in March or April in Hefei.
Technicians are installing the full superconducting experimental Tokamak fusion device in Hefei, capital city of east China's Anhui Province on Feb 4, 2006.
CONCLUSIONS:
In a most profound sense, mankind's quality of life depends on an acceptable response to the continually rising demand for energy. To be able to satisfy our future energy needs , we therefore have to invest in all viable energy options , compatible with our environment .Fusion is one of these options and is characterised by exclusive properties, some of which represent distinct advantages over the other major energy sources. They can be grouped around two aspects :
¢ Fuel: abundant supply of cheap fuels (D and Li);
They are non-radioactive, and their extraction does not cause any significant ecological problem.
¢ Safety: fusion reactors offer inherent, passive safety. They are not based on a neutron multiplication reaction and do not contain a large supply of fuel in their core. An uncontrolled burn of the Chernobyl type is excluded.
