Transcript The Search for WIMPS - Physics & Astronomy

The Search for
WIMPS
By Kristine Kovacs
The Big Bang and Beyond
What are WIMPS?
• WIMPS stands for
Weakly Interacting
Massive Particles
• WIMPS are particles
that are thought to
possibly be the
mysterious dark
matter that is missing
from the universe
Characteristics of WIMPS
• Predicted only by theory—have not yet
been found
• “exotic” particles—means that they are
different than the ordinary particles that
make up the world around us
• Can travel straight through solid objects
• Extremely difficult to detect because they
are not the only things zipping around—
there are also alpha particles, gammarays, electrons, and cosmic rays
Characteristics of WIMPS Cont.
• Masses are perhaps 10 to 100 times that
of protons
• Relatively heavy
• Move much slower than the speed of light
• Since they don’t interact with radiation,
they would not affect the observed
“smoothness” of the cosmic background
radiation
• Could contribute up to 90% of dark matter
Detection of WIMPS
• VERY hard to detect—
have not even been yet
• Many experiments
formed to try to be the
first to detect WIMPS
• Can be detected only
through very occasional
collisions with the nuclei
of a suitable target
• A collision causes the
nucleus to recoil slightly,
which can be detected
and measured in various
ways
Technologies
• ZEPLIN I, ZEPLIN II, ZEPLIN III-liquid xenon scintillators in
which the small amount of energy from the recoil causes
photons of light to be released from scintillator material
which can then be measured
• Plans for a larger experiment, ZEPLIN-MAX are in the
process of being drawn up
• CDMS (Cryogenic Dark Matter Search) Detector-senses
the recoil energy when a particle strikes the nucleus of an
atom in the crystals (the mass of silicon and germanium
crystals located at the heart of the CDMS sensor)
• UKDMC Project-1100 meters below ground in Europe,
where the thick rock acts as a natural filter of cosmic rays,
and only lets the WIMPS through into the caverns below,
where they can be detected
Pictures of Recent Technologies
A cut-away drawing of the
new ZEPLIN II detector
currently being constructed
The ZEPLIN I Detector
Works Cited
• http://www.bbc.co.uk/science/space/deeps
pace/darkmatter/wimps.shtml
• http://www.pbs.org/wnet/hawking/strange/
html/strange_wimps.html
• http://www.pparc.ac.uk/frontiers/latest/feat
ure.asp?article=13F5&style=feature
• http://www.space.com/scienceastronomy/g
eneralscience/dark_matter_000228.html