Antimatter.pptx - 123SeminarsOnly

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Antimatter.pptx - 123SeminarsOnly Powered By Docstoc
 Objectives
 What is antimatter?
 Antiparticles
 Annihilation
 Artificial production
 Applications
 To understand the basics of 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
Positrons - Electrons with a positive instead of
  negative charge. Discovered by Carl Anderson in 1932,
  positrons were the first evidence that antimatter
Anti-protons - Protons that have a negative instead of
  the usual positive charge. In 1955, researchers at the
  Berkeley Bevatron produced an antiproton.
 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.
    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.
 Ideal energy density for chemical reactions is 1
  x 10 7 (10^7) J/kg, for nuclear fission it is 8 x
  10 13 (10^13) J/kg and for nuclear fusion it is 3
  x 10 14 (10^14) J/kg, but for the matter-
  antimatter annihilation it is 9 x 10 16 (10^16)
  J/kg. This is 10 10 (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.
E=energy released by annihilation
M=mass of the particles get annihilated
C=speed of light in vaccuum
          HOW IT BECOMES A
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.
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.
  Most expensive substance on
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 !!!
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.
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".

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
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
     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 !!!
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

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