Antimatter Seminar Report by swenthomasovelil

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									Seminar Report ’05                                                         Antimatter


                  ANTIMATTER INTRODUCTION

          Antimatter rockets are what the majority of people think about when
 talking of rockets for the future. This is hardly surprising as it is such an
 attractive word for the writers of science fiction.


          It is, however, not only interesting in the realm of science fiction.
 Make no mistake; antimatter is real. Small amounts, in the order of nanograms,
 are produced at special facilities every year. It is also the most expensive
 substance of Earth; in 1999 the estimated cost for 1 gram of antimatter was
 about $62.5 trillion.


          The reason it is so attractive for propulsion is the energy density that
 it possesses. Consider that the 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 governed by Einstein's famous equation
 E=mc2, rather than just the part conversion that occurs in fission and fusion.




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                       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. Until just
 recently, the presence of antimatter in our universe was considered to be only
 theoretical. In 1928, British physicist Paul A.M. Dirac revised Einstein's
 famous equation E=mc2. Dirac said that Einstein didn't consider that the "m"
 in the equation -- mass -- could have negative properties as well as positive.
 Dirac's equation (E = + or - mc2) allowed for the existence of anti-particles in
 our universe. Scientists have since proven that several anti-particles exist.


          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. Here are some antimatter discoveries of the
 20th century:


       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.

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       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.

 Particle 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.


          The problem with developing antimatter propulsion is that there is a
 lack of antimatter existing in the universe. If there were equal amounts of
 matter and antimatter, we would likely see these reactions around us. Since
 antimatter doesn't exist around us, we don't see the light that would result from
 it colliding with matter.


          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.

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                  PRODUCTION OF ANTIMATTER

          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. 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.




                                  Atom smasher


 Antiproton Decelerator (AD)


          The Antiproton Decelerator is a very special machine compared to
 what already exists at CERN and other laboratories around the world. So far,
 an "antiparticle factory" consisted of a chain of several accelerators, each one
 performing one of the steps needed to produce antiparticles. The CERN
 antiproton complex is a very good example of this.




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          At the end of the 70's CERN built an antiproton source called the
 Antiproton Accumulator (AA). Its task was to produce and accumulate high-
 energy antiprotons to feed into the SPS in order to transform it into a "proton-
 antiproton collider".   As soon as antiprotons became available, physicists
 realized how much could be learned by using them at low energy, so CERN
 decided to build a new machine: LEAR, the Low Energy Antiproton Ring.
 Antiprotons accumulated in the AA were extracted, decelerated in the PS and
 then injected into LEAR for further deceleration. In 1986 a second ring, the
 Antiproton Collector (AC), was built around the existing AA in order to
 improve the antiproton production rate by a factor of 10.


          The AC is now being transformed into the AD, which will perform all
 the tasks that the AC, AA, PS and LEAR used to do with antiprotons, i.e.
 produce, collect, cool, decelerate and eventually extract them to the
 experiments.


 What does the AD consist of?


          The AD ring is an approximate circle with a circumference of 188 m.
 It consists of a vacuum pipe surrounded by a long sequence of vacuum pumps,
 magnets, radio-frequency cavities, high voltage instruments and electronic
 circuits. Each of these pieces has its specific function:
 -   Antiprotons circulate inside the vacuum pipe in order to avoid contact with
     normal matter (like air molecules), and annihilate. The vacuum must be
     optimal, therefore several vacuum pumps, which extract air, are placed
     around the pipe.
 -   Magnets as well are placed all around. There are two types of magnets: the
     dipoles (which have a North and a South pole, like the well-known
     horseshoe magnet) serve to change the direction of movement and make
     sure the particles stay within their circular track. They are also called

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     "bending magnets". Quadrupoles (which have four poles) are used as
     'lenses'. These "focusing magnets" make sure that the size of the beam is
     smaller than the size of the vacuum pipe.
 -   Magnetic fields can change the direction and size of the beam, but not its
     energy. To do this you need an electric field: this is provided by radio-
     frequency cavities that produce high voltages in synchronicity with the
     rotation of particles around the ring.
 -   Several other instruments are needed to perform more specific tasks: two
     cooling systems "squeeze" the beam in size and energy; one injection and
     one ejection system let the beam in and out of the machine.


 How does the AD work ?


          Antiparticles have to be created from energy (remember: E = mc2).
 This energy is obtained with protons that have been previously accelerated in
 the PS. These protons are smashed into a block of metal, called a target. We
 use Copper or Iridium targets mainly because they are easy to cool. Then, the
 abrupt stopping of such energetic particles releases a huge amount of energy
 into a small volume, heating it up to such temperatures that matter-antimatter
 particles are spontaneously created. In about one collision out of a million, an
 antiproton-proton pair is formed. But given the fact that about 10 trillion
 protons hit the target (about once per minute), this still makes a good 10
 million antiprotons heading towards the AD.


          The newly created antiprotons behave like a bunch of wild kids; they
 are produced almost at the speed of light, but not all of them have exactly the
 same energy (this is called "energy spread"). Moreover, they run randomly in
 all directions, also trying to break out 'sideways' ("transverse oscillations").
 Bending and focusing magnets make sure they stay on the right track, in the
 middle of the vacuum pipe, while they begin to race around in the ring.



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          At each turn, the strong electric fields inside the radio-frequency
 cavities begin to decelerate the antiprotons. Unfortunately, this deceleration
 increases the size of their transverse oscillations: if nothing is done to cure
 that, all antiprotons are lost when they eventually collide with the vacuum
 pipe. To avoid that, two methods have been invented: 'stochastic' and 'electron
 cooling'. Stochastic (or 'random') cooling works best at high speeds (around
 the speed of light, c), and electron cooling works better at low speed (still fast,
 but only 10-30 % of c). Their goal is to decrease energy spread and transverse
 oscillations of the antiproton beam.


          Finally, when the antiparticles speed is down to about 10% of the
 speed of light, the antiprotons squeezed group (called a "bunch") is ready to be
 ejected. One "deceleration cycle" is over: it has lasted about one minute.


          A strong 'kicker' magnet is fired in less than a millionth of a second,
 and at the next turn, all antiprotons are following a new path, which leads them
 into the beam pipes of the extraction line. There, additional dipole and
 quadrupole magnets steer the beam into one of the three experiments.


 The AD experiments


          Three experiments are installed in the Antiproton Decelerator's
 experimental hall:
 ASACUSA:Atomic Spectroscopy and Collisions using Slow Antiprotons
 ATHENA:Antihydrogen          Production     and   Precision    Experiments     and
 ATRAP:Cold Antihydrogen for Precise Laser Spectroscopy.
 ATHENA and ATRAP's goal is to produce antihydrogen in traps, by
 combining antiprotons delivered by the AD with positrons emitted by a
 radioactive source.



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          Antihydrogen atoms were first observed at CERN in 1995, and later
 (1997) at Fermilab. In both cases they were produced in flight, that means they
 moved at nearly the speed of light, i.e. much too fast to allow precise
 measurements on any of their proprieties! They made unique electrical signals
 in detectors that destroyed them almost immediately after they formed. Now
 the idea is to produce slow antihydrogen atoms and store them into "traps",
 allowing extremely accurate comparisons of the properties of hydrogen and
 antihydrogen.


          ASACUSA, on the other hand, will synthesize "exotic" atoms, in
 which an electron is replaced by an antiproton. Precise laser spectroscopy of
 these exotic atoms is expected to reveal lots of information on the behavior of
 atomic systems.




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                                 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 proprieties that can be used to keep them in "magnetic bottles".




                                  Portable trap




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                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.




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                     FUTURE OF ANTIMATTER


 Antimatter as a propulsion system


          This is not some incredible new technology that will power us
 throughout the galaxy. At the most basic level the antimatter rocket is still a
 Newtonian rocket, governed by the three laws of motion and it still conforms
 to Einstein's theory of special relativity, in other words it cannot exceed the
 speed of light.


          Still if we are enable to develop such a propulsion system 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!).This fact has led to the interesting observation that future
 advanced spacecraft, such as the antimatter rocket, will not be designed around
 their propellant tank like conventional craft. Instead the craft will be designed
 around the reactors (for nuclear craft) or around the systems and chambers to
 cause annihilation (for antimatter craft). Radiation shielding will also become
 a key component of spacecraft design.




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 Antimatter propulsion systems


          Once we have produced and stored the antimatter we can use it in
 propulsion by releasing it into a chamber and allowing it to annihilate with
 normal matter which produces its tremendous energy in the form of energetic
 sub-atomic particles. 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.
 The fact that there is this mass left over after the annihilation means that the
 full conversion of mass to energy has not occurred as it does in the electron-
 positron annihilation, therefore slightly less energy has been produced.


          This energy, however, still far exceeds any other method and the
 resulting particles allow this energy to be harnessed by directing it with
 magnetic forces. In other words the perfect reaction does not produce perfect
 propulsive result. Another important advantage for antimatter rockets over
 nuclear rockets is that heavy reactors are not required, the reaction is
 spontaneous. There are four main designs for an antimatter rocket, they are
 listed here in increasing specific impulse:
     Solid Core - Annihilation occurs inside a solid-core heat exchanger, the
      reaction superheats hydrogen propellant that is expelled through a nozzle.
      High efficiency and high thrust, but due to the materials the specific
      impulse is only 1000secs at best.
     Gas Core - Annihilation occurs in the hydrogen propellant. The charged
      pions are controlled in magnetic fields and superheat the hydrogen; there
      is some loss in the form of gamma rays that cannot be controlled. specific
      impulse of 2500secs.

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         Plasma Core - Annihilation of
            larger amounts of antimatter in
            hydrogen to produce a hot plasma.
            Plasma contained in magnetic
            fields, again some loss in form of
            gamma radiation, the plasma is
            expelled to produce thrust. There           Antimatter Spacecraft
            are no material constraints here so higher specific impulse is
            possible (anywhere from 5,000 to 100,000secs).
         Beam Core - Direct one to one annihilation, magnetic fields focus the
            energetic charged pions that are used directly as the exhausted
            propellant mass. These pions travel close to speed of light so the
            specific impulse could be greater than 10,000,000secs.


          The spacecraft will have to be designed to be very long as the
 annihilation products travel close to the speed of light.


 Journey time


           Estimates for travel times to Mars for an advanced antimatter rocket
 using the beam core approach 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.




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                     ANTIMATTER DETONATION

          Over 99.9% of the mass of neutral antimatter is accounted for by
 antiprotons and antineutrons. Their annihilation with protons and neutrons is a
 complicated process. A proton-antiproton pair can annihilate into a number of
 charged and neutral relativistic pions. Neutral pions, in turn, decay almost
 immediately into gamma rays; charged pions travel a few tens of meters and
 then decay further into muons and neutrinos. Finally, the muons decay into
 electrons and more neutrinos. Most of the energy (about 60%) is thus carried
 away by neutrinos, which have almost no interaction with matter and thus
 escape into outer space.


          The overall structure of energy output from an antimatter bomb is
 highly dependent on the amount of regular matter in the area surrounding the
 bomb. If the bomb is shielded by sufficient amounts of matter, the gamma rays
 are absorbed and the pions slow down before decaying. Part of the kinetic
 energy is thus transferred to the surrounding atoms, which heat up. In the event
 of an antimatter detonation in the open atmosphere, most of the energy will
 ultimately be carried away by the neutrinos, and the remainder by 10-100 MeV
 gamma rays. The neutrinos would pass through the earth without being
 attenuated, while gamma rays are relatively weakly absorbed by matter: they
 lose roughly half of their energy per 500-1000 m of air, compared to only
 20 cm of concrete. The explosion would not cause much physical damage
 because its energy would be evenly dispersed over large area, although the
 gamma rays may harm people standing nearby. Thus even if the impossible
 problem of producing enough antimatter were solved, the antimatter bomb
 would not be as practical or destructive as a conventional nuclear weapon.




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                     ANTIMATTER IN NATURE

          About 15 billion years ago, matter and antimatter were created in a
 gigantic Big Bang in equal amounts, at least according to today's best theory. It
 is therefore surprising that our Earth, the solar system, and our galaxy (the
 Milky Way) do not contain any antimatter.


          To explain this absence, scientists have come out with two
 possibilities: either antimatter completely disappeared during the history of
 universe, or matter and antimatter have been separated from each other to form
 different regions of the universe.


          In the second case, we would be located in a region where only
 matter exists (or rather what we call 'matter'), but some antimatter coming
 from an 'anti' region outside our galaxy could still have a chance to reach us.
 This antimatter would be in the form of anti-nuclei (like anti-Helium, anti-
 Carbon, etc..) as opposed to lighter antiparticles (such as antiprotons) which
 are also created in high energy collisions between ordinary matter. To search
 for this extragalactic antimatter, the best way is to place a particle detector in
 space.


 AMS


          A worldwide collaboration of physicists, lead by Nobel prize laureate
 Prof. Samuel Ting of MIT, decided to build the 'Alpha Magnetic
 Spectrometer', or AMS. AMS is a high-energy particle detector, which will
 try to detect the passage of such very small amounts of antimatter, while
 orbiting at an altitude of a few hundred kilometers above the atmosphere.




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          Some of the main challenges of the project are very technical: having
 to be carried on the Space Shuttle, each component of the apparatus has to be
 miniaturized as much as possible to keep the total volume to a maximum of 10
 cubic meters and the weight to a maximum of 3 tons (a typical high energy
 apparatus at LEP with the similar detecting principles is about 1000 cubic
 meters in volume and 100 tons in weight). Even more important is the power
 consumption: AMS should not need more than 2 kW (kilowatts) of electricity,
 provided by the solar panels of the Space Station. And 2kW is less than what a
 kitchen oven needs!




                                    AMS-01


          A first simpler version of the experiment, AMS-01, traveled on the
 Space Shuttle Discovery for a ten-day mission in 1998. The apparatus
 consisted of a 6-layer 'silicon microstrip track detector' surrounded by a
 permanent magnet and a few other systems.


          Silicon microstrips can localize the passage of charged particles with
 a precision of a few hundredth of a millimeter (less than a human hair). The
 magnet produced a magnetic field where incoming particles were deflected in
 opposite directions. Nuclei are thus identified by measuring both their mass

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 and charge. During the 10 days that AMS was in space, not a single
 antinucleus was seen among the 3 million nuclei that traversed the experiment.
 In 2004, a new version of the experiment, called AMS-02, will be installed on
 the International Space Station. AMS-02 will again be searching for any
 extragalactic antimatter, but this time with more sensitivity, over a longer time
 period and in a wider energy range.


          The new apparatus will be equipped with a superconducting magnet,
 providing a much higher magnetic field, and an enhanced silicon tracker, able
 to record billions of tracks of matter (and antimatter?) particles. Other
 detectors have also been added to the design to better identify and measure
 incoming particles and nuclei. AMS-02 will be installed on the long arm of the
 ISS and exposed to cosmic rays for three years.


          This very moment, a few modules of ISS are already orbiting over
 our heads. With the experimental data collected during this second mission,
 AMS hopes to find the last traces of big-bang antimatter, if there are any left!




                                     AMS-02




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                                 PROBLEMS

 Problems in Production


          We would need at least several milligrams of antimatter to fuel a
 beam core antimatter engine in local operations and several kilograms for
 interstellar travel to Alpha Centuri. Given that currently 1-10 nanograms of
 antiprotons are produced a year at Fermilab (Chicago) and CERN (Geneva), a
 beamed core engine is not feasible in the near future.


 Problems in Storage


          The Penning trap has been developed, it is a portable antiproton trap
 which is capable of storing 1010 (10^10) antiprotons for one week using the
 superposition of electric and magnetic fields. The next stage is an
 improvement to 1012 (10^12) antiproton storage. For complete antimatter
 propulsion it is thought that 1020 (10^20) anti-protons will need to be stored.




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                     FAQ’S ABOUT ANTIMATTER

 • What can antimatter be used for?


          There are several different uses for antimatter, the main one being for
 medical diagnostics where positrons are used to help identify different diseases
 with the Positron Emission Tomography (or PET scan). For other uses, we are
 still in the first phases of development and it's difficult to foresee what will
 happen in the next ten years.


 • Can we use antimatter to propel a car or a spaceship?


          In principle, yes, but in practice it is very difficult. You all know that
 the Star Trek Spaceship Enterprise flies around powered by antimatter. But in
 reality, making antimatter is so difficult that it is hard to foresee it ever being
 used as a propellant fuel. In order to propel a matter spacecraft weighing
 several tons up to the speed of light, you would need an equal amount of
 antimatter and, using the present technology, it would take millions and
 millions of years to produce a sufficient amount. However, if you had a gram
 of antimatter, you could drive your car for about 100.000 years.


 • What does antimatter look like?


          Matter and antimatter are identical. Looking at an object means
 seeing the photons coming from that object; however, photons come from both
 matter and antimatter. If there were a distant galaxy made out of antimatter,
 you couldn't distinguish it from a matter galaxy just by seeing the light from it.




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 • How can you be so sure there is not antimatter around?


          If there was antimatter here, around us, it would annihilate with
 matter and we would see light coming out. But we don't...About the possibility
 of antimatter in space (antistars or antigalaxies), theorist have reasons to
 believe that the Universe is all made of matter. But we are not 100% sure, and
 that's way there are experiments, like AMS, which are going to look for it.


 • If the only difference between a particle and its antiparticle is the
 charge, how do you distinguish a neutron from an antineutron ?


          Neutrons are made of quarks, and antineutrons are made of
 antiquarks. Quarks and antiquarks have opposite charges, even though they
 sum up to zero in both cases. And a very good way to recognize them is to put
 a neutron close to an antineutron and see how they immediately annihilate.


 • What about antiphotons?


          Photons have zero charge and do not contain inside objects that are
 charged, so a photon can not be distinguished from an antiphoton. Photon and
 antiphotons are the same thing, i.e. the photon is its own antiparticle.


 • How do sound waves propagate in antimatter?


          If there is a difference between matter and antimatter, it is very very
 tiny, that's why we are doing experiments here at CERN to investigate it. They
 are so similar that sound waves, that are vibrations of matter or antimatter,
 would be identical. An antimatter piano would sound exactly as a matter one.




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 • How does the gravitational field act on antimatter?


           The gravitational force depends from the energy of an object, and
 since matter and antimatter have both positive energy, gravitation acts on them
 in the same way. This means that an object made of matter and one made of
 antimatter would both stand on the floor, the latter one not flying off the sky.




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                              CONCLUSION

          Due to the highest energy release per unit mass of any known
 reaction ,we can say that antimatter will be a future energy source but first
 need a reliable method of producing large amount of it.




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                                  GLOSSARY

 Cooling: By analogy with the kinetic theory of gases where heat is equivalent
 to disorder, the term “cooling” designates the reduction of beam’s transverse
 dimensions and energy spread. Different techniques can be used to this effect.
 Electron cooling, more effective at low energy, uses an electron beam merged
 with the antiproton beam, and acts as a heat exchanger between the two beams.
 In the case of stochastic cooling, an error signal generated in a monitor is fed
 back, via a collector, to the beam sample which created it, eventually centering
 the sample’s characteristics towards the average value, after a large number of
 passages through the apparatus.


 Muon: an elementary particle having a mass 209 times that of the electron, a
 negative electric charge, and mean lifetime of 2.210-6 seconds.


 Neutrino: An electrically neutral particle that is often emitted in the process of
 radioactive decay of nuclei. Neutrinos are difficult to detect, and their
 existence was postulated twenty years before the first one was actually
 discovered in the laboratory. Millions of neutrinos produces by nuclear
 reactions in the sun pass through your body every second without disturbing
 any atom.


 Pion: it is produced either in a neutral form with a mass 264 times that of an
 electron and a mean lifetime of 8.410-7 seconds or in a positively or
 negatively charged form with a mass 273 times that of an electron and a mean
 life time of 2.610-8 seconds.


 Quarks: Subatomic particles which possess a fractional electric charge, and of
 which protons, neutrons etc. are believed to be composed.


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 Radio-Frequency or RF: The alternating voltage that provide (or takes)
 energy to (or from) the beam to accelerate (or decelerate) it.


 Specific impulse: It is an important parameter in spacecraft propulsion. It is
 the thrust produced per unit weight flow rate of the propellant. The unit is in
 seconds.


 Synchrotron: Modern circular accelerator, where the particles are guided by
 dipole magnets, focused by quadrupole magnets, and accelerated by RF
 electric fields.


 eV: The electron-Volt (eV) is the energy unit which corresponds to the
 acceleration of a particle having the charge of the electron through a voltage
 difference of one volt.


 LEAR: CERN’s Low Energy Antiproton Ring, where the first nine atoms of
 anti- hydrogen were observed.


 PS: CERN’s Proton Synchrotron, which accelerated protons to its nominal
 energy of 25 GeV for the first time in 1959, it has been upgraded to also
 accelerate heavy ions, leptons (electrons and positrons), and antiprotons. Its
 now at the heart of CERN’s accelerator complex.


 LEP: CERN’s 100 GeV Large Electron-Positron collider, started in 1989, and
 due to stop at the end of 2000. Its collision energy has now been upgraded to
 202 GeV.




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                             REFERENCE


       Fundamentals of Compressible Flow with Aircraft & Rocket
          propulsion by S. M. Yahiya
       http://livefromcern.web.cern.ch
       http://public.web.cern.ch




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                                 ABSTRACT


          Antimatter is exactly what you might think it is -- the opposite of
 normal matter, of which the majority of our universe is made. Until just
 recently, the presence of antimatter in our universe was considered to be only
 theoretical. In 1928, British physicist Paul A.M. Dirac revised Einstein's
 famous equation E=mc2. Dirac said that Einstein didn't consider that the "m"
 in the equation -- mass -- could have negative properties as well as positive.
 Dirac's equation (E = + or - mc2) allowed for the existence of anti-particles in
 our universe. Scientists have since proven that several anti-particles exist.


          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.




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Seminar Report ’05                        Antimatter




                        CONTENTS



         ANTIMATTER INTRODUCTION     1

         WHAT IS ANTIMATTER?         2

         PRODUCTION OF ANTIMATTER    4

         STORAGE                     9

         APPLICATION OF ANTIMATTER   10

         FUTURE OF ANTIMATTER        11

         ANTIMATTER DETONATION       14

         ANTIMATTER IN NATURE        15

         PROBLEMS                    18

         FAQ’S ABOUT ANTIMATTER      19

         CONCLUSION                  22

         GLOSSARY                    23

         REFERENCE                   25




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Seminar Report ’05                                                     Antimatter



                        ACKNOWLEDGEMENT

            In the name of Almighty God, I take this opportunity to express my
heartfelt gratitude to Dr. T C Peter, Head of the Department of Mechanical
Engineering and all teaching staffs of M E S College of Engineering, for their
support and valuable help.


            I extend my special thanks to Mr. Alex Bernard V K, staff-in-charge
for the pains he took in coordinating the seminar and also for his kind support
and help.


            Last but not the least, I express my special thanks to my parents and
friends, who stood by me and encouraged me.




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