1. Fusion: Creating a Star on Earth-Produced by General Atomics in conjunction with schools in the San Diego area. This presentation will focus on the oldest, and newest, form of energy, fusion, and what the promise of fusion means for our energy-hungry future.

2. The Earth: When viewed from the surface, it seems large with a never-ending supply of resources. When viewed from space, however, a truer picture emerges: We live on a small, finite size spaceship, the stewardship of which is important to us all.

3. As the Earth's human population has grown, so too, has the need for more energy. Our individual energy needs are great and energy sources are limited. The consequence of meeting these energy demands directly impacts our environment.

4. Why is Fusion Important? Why should we care? What can we do?

5. From the historical perspective, the first large-scale energy sources to be exploited were the fossil fuels. Coal was the first of these in the 19th century.

6. Commercial uses for oil were discovered in the late 19th and early 20th century.

7. Natural gas came into use in the early 20th century
Natural gas came into use in the early 20th century. It is also a form of fossil fuel that comes from deep underground.

8. Fission, the splitting of the atom, was theoretically conceived in the 1930s with the first controlled chain reaction taking place on December 2, 1942 at the University of Chicago. By the 1950s the first electricity-producing nuclear power plants were in operation.

9. Other energy sources such as hydroelectric, wind, geothermal, and solar have also been developed.

10. As the need for energy has increased, new technologies were developed to meet the need. However, each of these energy producing technologies has brought with it disadvantages as well. Coal, while it is abundant, produces air pollution and acid rain and an increase in CO2 emission. The combustion of oil and its by-products also increases CO2 levels and causes air pollution. The world's supply of oil is finite. Natural gas burns cleanly but is in limited supply and also produces some CO2.

11. Nuclear power causes little air pollution, but hazards exist for accidents and disposal of nuclear waste. Hydroelectric, wind, geothermal, and solar energy sources remain limited to specialized geographic regions and are relatively minor suppliers in the overall energy picture. Combined, they are predicted to supply only 7% of our future energy needs.

12. The fossil fuels, gas and oil, which took millions of years to produce, will be used up within a hundred years.

13. An energy shortfall could occur as early as the mid-21 century as demand for energy far outstrips supply.

14. Fossil fuel is also environmentally costly
Fossil fuel is also environmentally costly. 64 lbs of CO2 are produced per American per day from fossil fuel usage.

15. Fortunately, a new energy source is presently being developed which can provide an abundant source of future energy. It is actually the most ancient of all power sources-FUSION-which powers the thermonuclear engines of the sun and stars.

16. All life on earth is directly or indirectly dependent on the fusion energy of the sun.

17. To understand fusion, one approach is to compare it to what it is not: fission. In nuclear fission, a heavy atom such as uranium is split, which releases energy. This reaction has already been exploited to produce electricity in nuclear power plants.

18. Simply stated, in fission, a large atom is split into smaller atoms, releasing energy

19. In fusion, two light atoms such as hydrogen are brought together (or fused) to form a new element, and subsequent release of energy.

21. Fusion fuel, hydrogen, is found in ordinary water and is cheap and abundant. Unlike fission, the physics of fusion make it inherently safer-a fusion reactor cannot go through a meltdown. Waste generated by fusion is expected to be less radioactive and to have a shorter half life, and is thus easier to dispose of than fission waste. Clearly, there are many advantages to fusion, and the process looks simple.

22. So why aren't fusion power plants here now? What's the holdup

23. To understand better, let's start at the beginning
To understand better, let's start at the beginning An atom in one of the three common states of matter possesses a nucleus containing protons and neutrons. Orbiting around the nucleus are many electrons. The number of protons is the atomic number, while the number of protons and neutrons together essentially make up the atomic mass of an atom.

24. The three most common states of matter found on earth are solid, liquid, and gas. Plasma, the fourth state of matter, can be created on earth by supplying sufficient heat.

25. However, in the universe, plasma is the most abundant state of matter
However, in the universe, plasma is the most abundant state of matter. It makes up the sun, stars, and much of the interstellar material.

26. In solids, liquids, and gases, electrons are normally bound to the nucleus of an atom.

27. In a plasma, the electrons are stripped away from the nucleus
In a plasma, the electrons are stripped away from the nucleus. Examples of plasma here on earth include fluorescent lights, lightning, aurorae, and neon signs.

28. Since nuclei are positively charged, they will repel other nuclei
Since nuclei are positively charged, they will repel other nuclei. Only tremendous heat and pressure will cause the nuclei to fuse. Such temperatures and pressures occur naturally in stars where they are ultimately caused by gravitational forces.

29. The primary fuel of fusion is hydrogen, a gas which is the lightest element.

30. Hydrogen has one proton, one electron, and no neutrons
Hydrogen has one proton, one electron, and no neutrons. Its atomic number is 1 and its atomic mass is approximately 1 since it has no neutrons (the electron mass is 1/1836 of the proton mass).

31. There are three isotopes of hydrogen which differ in the number of neutrons they possess. The hydrogen isotope has only one proton, the deuterium isotope has one proton and one neutron and the tritium isotope has one proton and two neutrons. Deuterium (D) is designated as 1H2 and tritium (T) is designated as 1H3.

32. In the sun, it is believed that the following reaction takes place: (1) When hydrogen atoms fuse, one of the protons is converted into a neutron and positron resulting in the formation of deuterium. (2) Deuterium and another hydrogen fuse to form the lightest isotope of helium-2He3, releasing gamma radiation. (3) Two light isotopes of helium 2He3 combine, forming 2He4, the common form of helium and two free protons (hydrogen).

33. In the end, two hydrogen nuclei have combined, eventually fusing to form helium and releasing energy.

34. When hydrogen atoms fuse into helium, a small amount of mass is lost-38 parts out of 10,000. This lost mass is converted into energy.

35. While the amount of mass lost may seem small, this small mass is converted into huge quantities of energy. Using Einstein's formula E=mc2, the amount of energy produced when mass is converted into energy can be calculated. For example, if a 1 gram raisin was completely converted into energy, the resulting energy release would be the equivalent of approximately 10,000 tons of TNT.

36. Of all the elements known to man, the light elements (hydrogen, helium
Of all the elements known to man, the light elements (hydrogen, helium ...) liberate energy when they combine (fuse) to form heavy elements. On the other end of the periodic table, the heavy elements (uranium, plutonium ...) liberate energy when they split (fission) to form lighter elements. The fusion process produces much more energy than the fission process per unit mass of fuel.

37. As you can see, the amount of energy released in the fusion process is enormous. We get back 2000 times more energy in the process than we put in.

38. As a result, very little fusion fuel is needed to produce enormous amounts of energy as compared to fission, oil, and coal.

39. Viewed another way, 50 cups of sea water (from which deuterium can be extracted) contain the same amount of energy as 2 tons of coal or a thimble of deuterium is equivalent to 20 tons of coal.

40. Much less radioactive waste results from fusion than from fission or coal plants. During the D-T reaction, neutrons are released which cause the reactor vessel to become radioactive. This radioactivity can be greatly reduced by using "low activation" materials. Such materials would have half-lives of tens of years, rather than the millions or billions of years for radioactive waste produced from fission.

41. Research going on presently attempts to make constructive use of fusion energy by developing power plants to produce electricity. How can the sun's energy and fusion be harnessed on earth? Let's start with the fuel.

42. The fusion of two hydrogen (H) atoms requires much higher temperatures than do mixtures of its two isotopes deuterium (D) and tritium (T) .

43. A 50/50 mixture of D/T is the easiest mixture to use since it fuses at the lowest temperature and its energy yield is the largest.

44. In the D-T reaction, only 20% of input energy is used to sustain the reaction. The remaining 80% is used to produce electricity.

45. How readily available are deuterium and tritium
How readily available are deuterium and tritium? Deuterium can easily be extracted from seawater, where 1 in 6500 hydrogen atoms is deuterium. This water is known as "heavy water." Tritium can be bred from lithium, which is abundant in the Earth's crust. Thus, the fuel for the fusion reaction is considered inexhaustible and very accessible.

46. Heating the D-T fuel to temperatures in excess of 100M¡C-hotter than the core of a star-is obviously not easy. Some heating methods include: (1) compressing the fuel-like air in a piston, (2) forcing an internal electric current through it-like a toaster, (3) bombarding the fuel with high energy neutral particles, and (4) absorbing power from microwaves or lasers.

47. Since the plasma reaches a temperature of many millions of degrees, confining it is very difficult. Three methods for plasma confinement exist: (1) Gravitational (not feasible on Earth), (2) Inertial, and (3) Magnetic.

48. Lasers for inertial confinement fusion can provide trillions of watts of directed power to heat a small pellet of fuel to many millions of degrees Centigrade.

49. The inertial confinement concept uses high power lasers producing up to 100 trillion watts of power to heat the surface layer of a fuel pellet-an ablator. The outward streaming ablator material produces an inward directed force that compresses the D-T fuel in the pellet core to 20 times the density of lead. Essentially, the process throws the material together to make it fuse.

50. Careful tailoring of the implosion produces compression to several thousand times atmospheric pressure and a temperature of 100,000,000¡C. The thermonuclear burn of the fuel will produce a fusion yield many times the driver input energy.

51. However, the most successful method for containing plasma thus far is a magnetic bottle which is toroidal-or doughnut- shaped, where the plasma forms a continuous circuit. The plasma is created in a vacuum chamber from which air has been removed and replaced by fusion fuel, D and T.

52. No material can withstand the 150,000,000¡C fireball of a fusion plasma. Fusion plasmas are 100,000 times less dense than air, and cool quickly if they touch the wall of the vacuum chamber.

53. Fortunately, the physical characteristics of plasma allow it to be contained by magnetic confinement. Plasma particles are charged, conduct electricity, and can be constrained magnetically.

54. In the presence of magnetic fields, charged particles orbit around the magnetic field lines. They can generally travel only parallel to those lines and with the proper orientation of the lines the particles can be prevented from touching material walls.

55. The most highly developed design is the tokamak, which was invented by the Russians. The tokamak uses strong externally applied magnetic fields to contain the plasma and maintain separation from the evacuated chamber walls.

56. Where are the current major fusion energy research projects?

57. There are several major fusion programs worldwide
There are several major fusion programs worldwide. The complexity and cost require a high degree of international collaboration. Private industry and governmental agencies are also cooperating. The programs and current major devices worldwide include: (1) JET from the European Community located in England, (2) JT-60 in Japan, and (3) TFTR in Princeton, New Jersey, DIII-D in San Diego, California and NOVA in Livermore, California.

58. NOVA at the Lawrence Livermore labs in Livermore, California.

59. TFTR at Princeton Plasma Physics Laboratory in Princeton, New Jersey

60. The DIII-D Tokamak at General Atomics in San Diego, California

61. What does the future of fusion research hold
What does the future of fusion research hold? ITER, the International Thermonuclear Experimental Reactor, is the next generation large device. The ITER is a joint cooperative effort between Europe, Japan, U.S., and Russia.

62. It will be by far the largest fusion reactor ever built; 30 meters in diameter and 30 meters tall

63. It is being designed by an international consortium of engineers and scientists right here in San Diego. The United States, Europe, Japan, and Russia will all take part. It is a six year, $1.2 billion endeavor intending to produce the design of the ITER fusion reactor.

64. What is the current status of these fusion programs
What is the current status of these fusion programs? Is fusion in our near or distant future? Here the quality of confinement (sec/m^3) vs. ion temperature (keV) is depicted. The first goal is engineering break-even, followed by ignition, followed by the later goal of commercial viability.

65. Here are the latest results
Here are the latest results. If advancements continue at the present rate, energy break-even could be accomplished by the year Commercial power plants could then come on line just as the Earth's oil gauge becomes critically low-about the years