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