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Antimatter:Past, Present & Future
Presentation By
Paramita BaraiIn Course Phys 6410:
Introductory Nuclear and Particle Physics Instructor: Dr. Xiaochun He
Department of Physics and Astronomy
Georgia State University
May, 2003
Contents Introduction to Antimatter Matter-Antimatter Asymmetry after Big Bang History of Antimatter till Today Antihydrogen Atom Production Uses of Antimatter Antimatter Propulsion Missions to Detect Antimatter in the Universe Present Status of Antimatter Search Further Scopes
Introduction to Antimatter Every matter particle has
antiparticle, most properties same, but few are different (charge)
Mass- Energy interconversion Matter antimatter annihilate to
form energy Always particle-antiparticle pair
created from energy Our world is of matter, so
should have equal amount of antimatter …
Where is the antimatter gone ? We don’t see any around today !!!
Matter-Antimatter Asymmetry After Big Bang
At origin – continuous mass energy interconversion – particles antiparticles created and annihilated
Universe expanded and cooled Somehow for every million pairs
one more particle created Temperature dropped, no longer
particle creation, all antiparticles destroyed
Remaining particles made up the stars, planets, trees, you and me …
CMBR: Relic of matter antimatter battle
History of Antimatter till Today
1928: Prediction of antiparticle by Paul Dirac
1930: Positron detected 1955: Antiproton and
Antineutron 1965: Antideutron 1995: Production of first
antihydrogen atom 2002 (16th sept):
Controlled production of large no. of antihydrogen atoms
Antihydrogen Atom Production Accelerated proton - hits metal
target, proton antiproton pair created from energy released
Antiprotons collected in a beam by electric field, the beam controlled by bending and focusing magnets
Radio frequency cavity slows down the antiprotons
When c/10, antiproton bunch squeezed out to new path by magnets, and stored in traps by magnetic field
Positrons collected from decay of a radioactive isotope
Positrons and antiprotons in mixing trap from antihydrogen atom
Practical Uses of Antimatter
Medical frontier
PET (Positron Emission Tomography) Scan Brain Other Parts of Body
Early and effective diagnosis
Antimatter Propulsion
Matter antimatter annihilations ultimate source of energy
Speculations about antimatter fueled rockets, going to far off stars
Missions to Detect Antimatter in Universe
Try to detect extensive regions of gamma rays coming from matter antimatter annihilations
Search for galactic and extragalactic antinuclei, antiatoms – antiparticle detector in space Balloon experiments
(IMAX) By Satellites
AMS: (ISS in 2004)
Present Status Of Antimatter Search
No evidence of vast regions of antimatter
Detected in universe
at isolated spots
In milky way Antimatter clouds at
center, origin not sure
Antimatter annihilation radiation
Further Scopes
Study antiatom properties, and compare with that of atom
Explain perceived antimatter asymmetry of universe In 1999, Fermilab charge parity violation
discovered Detect antimatter
AMS ( Alpha magnetic Spectrometer)
THANK YOU
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