Antimmatter Essay Research Paper Really long Physics — страница 2

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particles. Intense studies on storage devices such as these are underway using normal matter ions. This type of storage device is known as an ion trap. This is a good intermediate holding device for antimatter because it allows time for the particles to be cooled and decelerated. The Japanese have created traps that can hold 10 to 1016 antiprotons. However, these traps would be so large, that they would require huge amounts of energy. Although, the future is looking promising. The combination of these methods and new technology may allow for high density storage. This combined with the production notes expected in the next decade open the possibility of using antiprotons in applications other than basic research. Anti Protons have the highest energy density (9×1016 J./kg.) of

any other material known to man. The annihilation of an antiproton with a proton produces 1000 times the energy per unit mass of reactants thatn the fission of Uranium. Extrapolation of current technological growth reveals a future potential for low mass antiproton storage, transfer, and conversion to energy. However, the energy, and therefore financial investment is large. Consequently, antiproton energy sources would only be useful in areas where a low mass/high energy yield is important. Two such fields are biomedical and deep space propulsion application. The difficulty in these concepts is the conversion of the form of energy yielded by annilation (4 gamma rays and 3 pions), to the desired form of energy. The average kinetic energy?s produced from a single annialation are

243 MeV and 196 MeV for pions and gamma rays, respectively. The biomedical need for antiproton seem to be the most promising and near term use for the particles. The particular use for antimatter ifs in the area of biomedical radioisotope generation. These isotopes are currently used in established procedures such as Positron Emission Tomography (PET), which detects many forms of cancer, maps activity in the brain, and helps to understand pathological afflictions such as Alzheimer?s disease. The availability of the isotopes is currently limited to expensive production facilities and to the range that can be covered within the half life of the isotope. Only 40 cyclotrons for PET isotope production exist nationwide whereas 1700 hospitals possess the imaging capabilities. A portable

source of antiprotons would due away with the expensive cyclotron machines. The isotopes could be created by bombarding larger atoms with antiprotons to annialate protons and thus form the necessary isotopes. This process would increase the availability of PET machines 100 fold. Another use would be for advanced propulsion systems. The problem we now face in space exploration is we are limited in efficiency with current technology. Spoken plainly, bigger is no longer better. To get to some of our closest astrological destinations (Kulper Belt, the heliopause, or even our closest star, Alpha Centari) will require more then just a big ass rocket. Instead reaching such destinations will require revolutionary advances in propulsion to achieve their goals within reasonable time

frames. As mentioned before antimatter has the highest specific energy of any source known to man. It would be of great use as part of a propulsion system. The problem with such an idea is the form of energy. The way a conventional rocket works is a fuel is burned and the volume of the products is greater then the fuel. Therefore it shoots out the bottom of the rocket. The more mass you can shoot out of a given space (in a given time) determines the thrust force the rocket can deliver. In the case of antimatter there is no mass to be shot out of the bottom. The pre dominate plan for bridging this gap is using a solid core engine. Solid core engines are not new concepts. They were developed and tested in the 1960?s under the NERVA program. They were originally developed using a

nuclear fission reaction as the source of energy. The basic engine design revolves around the use of a solid, honeycomb tungsten core. This design, and other components, had been thoroughly tested in the NERVA program so the design seems reasonable. The way the engine would work (in basic terms) is antimatter would be annialated and core would be heated up by the reaction. This energy would then be used to heat a propellant. The likely repellant would be liquid hydrogen (LH3). This would involve liquid hydrogen turbo pumps which have already been tested. Also, the heating of liquid hydrogen would present a large volume expansion (from liquid to gas phase) and therefore propel large quantities of mass out of the engine. The core is the problem in such an engine. Tungsten has a