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ANTIMATTER TECHNOLOGY. CONTENTS. Objectives What is antimatter? Antiparticles Annihilation Artificial production Applications. OBJECTIVES. To understand the basics of antimatter technology. What is Antimatter?.
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CONTENTS • Objectives • What is antimatter? • Antiparticles • Annihilation • Artificial production • Applications
OBJECTIVES • To understand the basics of antimatter technology.
What is Antimatter? Antimatter is exactly what you might think it is -- the opposite of normal matter, of which the majority of our universe is made. These anti-particles are, literally, mirror images of normal matter. Each anti-particle has the same mass as its corresponding particle, but the electrical charges are reversed.
ANTIPARTICLES Positrons- Electrons with a positive instead of negative charge. Discovered by Carl Anderson in 1932, positrons were the first evidence that antimatter existed. Anti-protons - Protons that have a negative instead of the usual positive charge. In 1955, researchers at the Berkeley Bevatron produced an antiproton. Anti-atoms Pairing together positrons and antiprotons, scientists at CERN, the European Organization for Nuclear Research, created the first anti-atom. Nine anti-hydrogen atoms were created, each lasting only 40 nanoseconds. As of 1998, CERN researchers were pushing the production of anti-hydrogen atoms to 2,000 per hour.
ANNIHILATION When antimatter comes into contact with normal matter, these equal but opposite particles collide to produce an explosion emitting pure radiation, which travels out of the point of the explosion at the speed of light. Both particles that created the explosion are completely annihilated, leaving behind other subatomic particles. The explosion that occurs when antimatter and matter interact transfers the entire mass of both objects into energy. Scientists believe that this energy is more powerful than any that can be generated by other propulsion methods.
100% EFFICIENT PROCESS ! Ideal energy density for chemical reactions is 1 x 107 (10^7) J/kg, for nuclear fission it is 8 x 1013 (10^13) J/kg and for nuclear fusion it is 3 x 1014 (10^14) J/kg, but for the matter-antimatter annihilation it is 9 x 1016 (10^16) J/kg. This is 1010 (10 billion) times that of conventional chemical propellants. This represents the highest energy release per unit mass of any known reaction in physics. The reason for this is that the annihilation is the complete conversion of matter into energy , rather than just the part conversion that occurs in fission and fusion.
EINSTEIN’S e=mc2 One of einstein’s greatest insight was to realize that matter and energy are actually diferent forms of the same thing . Matter can be turned in to energy and energy in to matter . Einstein’s formula tells us the amount of energy a particular amount of matter will be equivalent to if it is suddenly converted in to energy . This is what happens in annihilation. The amount of energy released can be calculated using einstein’s formula e=mc2.
Where E=energy released by annihilation M=mass of the particles get annihilated C=speed of light in vaccuum
HOW IT BECOMES A TECHNOLOGY! Antimatter study becomes extremely important as the energy released during annihilation of matter and antimatter can be used to meet our energy requirements . Scientists in famous research facilities are working on to make an effective way to use energy released through annihilation for various purposes and also a safe facility to store antimatter in considerable quantities so that it can be used.
ARTIFICIAL PRODUCTION There is technology available to create antimatter through the use of high-energy particle colliders, also called "atom smashers." Atom smashers, like CERN, are large tunnels lined with powerful super magnets that circle around to propel atoms at near-light speeds. When an atom is sent through this accelerator, it slams into a target, creating particles. Some of these particles are antiparticles that are separated out by the magnetic field.
ATOM SMASHER These high-energy particle accelerators only produce one or two picograms of antiprotons each year. A picogram is a trillionth of a gram. All of the antiprotons produced at CERN in one year would be enough to light a 100-watt electric light bulb for three seconds.
Most expensive substance on earth! The highly complex and sophisticated nature of artificial production of antimatter has made it the most expensive substance on earth. In 1999,the estimated cost for 1 gram of antimatter was about $62.5 trillion !!!
NATURAL OCCURANCE It is possible that particles outnumbered anti-particles at the time of the Big Bang. As stated above, the collision of particles and anti-particles destroys both. And because there may have been more particles in the universe to start with, those are all that's left. There may be no naturally-existing anti-particles in our universe today. However, scientists discovered a possible deposit of antimatter near the center of the galaxy in 1977. If that does exist, it would mean that antimatter exists naturally, and the need to make our own antimatter would be eliminated.
ANTIMATTER STORAGE • Antiparticles have either a positive or a negative electrical charge, so they can be stored in what we call a trap which has the appropriate configuration of electrical and magnetic fields to keep them confined in a small place. Of course, this has to be done in good vacuum to avoid collisions with matter particles. Antiatoms are electrically neutral, but they have magnetic properties that can be used to keep them in "magnetic bottles".
APPLICATION OF ANTIMATTER PET Scan • Particle physicists regularly use collisions between electrons and their antiparticles, positrons, to investigate matter and fundamental forces at high energies. • When electron and positron meet, they annihilate, turning into energy which, at high energies, can rematerialize as new particles and antiparticles. This is what happens at machines such as the Large Electron Positron (LEP) collider at CERN. • At low energies, however, the electron-positron annihilations can be put to different uses, for example to reveal the workings of the brain in the technique called Positron Emission Tomography (PET). In PET, the positrons come from the decay of radioactive nuclei incorporated in a special fluid injected into the patient. The positrons then annihilate with electrons in nearby atoms. As the electron and positron are almost at rest when they annihilate, there is not enough annihilation energy to make even the lightest particle and antiparticle (the electron and the positron), so the energy emerges as two gamma rays, which shoot off in opposite directions to conserve momentum.
Antimatter as a propulsion system if we are enable to develop a propulsion system which uses antimatter as the source of energy in the future it will surely render any other Newtonian rocket obsolete overnight, the system has the highest predicted efficiency, specific impulse and probably the highest thrust to weight ratio. There does seem to be a serious amount of disagreement over this last point, the general feeling seems to be that the thrust to weight will at least comparable to today's very powerful chemical rockets. What this means is that only 100 milligrams (1/10 gram) of antimatter would be needed to match the total propulsive energy of the Space Shuttle (all those huge tanks of fuel!).
Antimatter propulsion system There are actually two choices for propulsion. Well electron-positron annihilation produces high energy gamma rays which are impossible to control, hence useless for propulsion, and on top of this are potentially very dangerous. Whereas the proton-antiproton annihilation produces charged particles (mostly pions moving at velocities close to that of light) that can be directed with magnetic fields, maximizing propellant mass
JOURNEY TIME OF AN ANTIMATTER ROCKET! Estimates for travel times to Mars for an advanced antimatter rocket are anywhere from 24 hours to 2 weeks, it is probable that it will be somewhere in between. Compare this to the space shuttle using its conventional chemical propulsion when a trip to Mars would take between 1 and 2 years !!!
CONCLUSION Antimatter indeed has the potential of becoming the most efficient source of energy. But as the artificial production of antimatter has made it the most expensive substance on earth , we still have to wait until we find it naturally . In sometime in future we can hope that we will be capable of travelling anywhere inside our galaxy with the help of antimatter spaceships.
