Transcript Halfgeleiders en sensoren.

Semiconductors and
sensors
An example on how to use them.
Possible uses of semiconductor
material
• 1. As passive elements (sensors)
• 2. As active elements: handling of signals
(diodes, transistors,...)
• 3. In computers (chips, memory,...)
• ....
• We concentrate on the first and the second
use.
Accelerators.
The biggest particle
accelerator in the world
is built in the
neighbourhood of
Geneva, some 100 m
beneath the surface.
In a tunnel that is 27 km long,
electrons en positrons make
11000 turns a SECOND. They
almost have the speed of light.
Physicists organise
collisions of very
high energetic
electrons and
protons
...... in the hart of
gigantic detectors.
These detectors are used
to measure and calculate
the track,energy, charge,
velocity and mass of
hundreds of particles
that emerge from these
collisions.
Detectors
These detectors are
shaped like onions, built
of different layers. These
layers measure different
quantities of the
particles. Some of them
are made of
semiconductor material.
Every sensor
in the
detector
produces
information...
... there are
thousands
of these
sensors...
... and all this information should be passed to computers
without errors!
An example: the UA1
This detector is a cilinder. It is hollow and inside there are thousands
of charged wires. A charged particle that goes trough the detector
causes a signal in all the wires it passes by.
The cilinder is 15 m
long and 3 m high.
The signals caused by
particles passing by are
analysed by
computers. Knowing
from which wire the
signals come from,
they can reconstruct
the track of these
particles.
With this detector very rare particles (W en Z
bosons), were found. In 1983, this was so
important that only a few years later this work
was rewarded with a Nobelprize.
So, the wires transport these signals to the side of the cilinder,
where it enters a print. Every wire is connected to a different
print. Let ‘s have a closer look....
.... and closer!
.... and closer...
... or still closer!
Diodes
Transistors
IC’s
Operational
amplifiers.
Chips
Memories
....
....
...tens of
thousands!
Everything based on semiconductortechnology!
Finally...
Thousands of wires, many
different particles passing
by each second, causing
signals in many wires...
Get it?
Indeed, the enormous
computer capacity that is
needed to do all this
calculations. And again...
computers also are based on
semiconductor technology!
More information?
http://webcast.cern.ch/Projects/WebLectureArchive/index.html
http://wwwpdg.cern.ch/pdg/cpep/adventure_home.html
http://wwwpdg.cern.ch/pdg/cpep/accel.html
http://www.fnal.gov/pub/hep_descript.html
http://wwwpdg.cern.ch/pdg/cpep/detectors.html
http://alephwww.cern.ch/EDUC/alephdesc.html
P.S.
Of course, one computer was not sufficient to do all
this work . They needed more, and it was
absolutely necessary that these computers could
« talk » to each other. That is exactly why the
WWW was developed by CERN: to let physicists
exchange data more easily.