SUPERCONDUCTORS

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SUPERCONDUCTORS
and
telescopes
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Superconductors, the meissner effect and magnets
When a superconductor is in an applied magnetic
field, the field surrounds superconductor, but
doesnt penetrate.
Meissner effect
Applied magnetic field induces a current, which
produces a magnetic field that cancels applied
magnetic field inside superconductor.
Magnetic field inside superconductor is always
zero
The currents produced in a superconductor lead to
levitation of a magnet.
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The interaction between magnets /magnetic fields
and superconductors has been applied to develop
the...
Maglev train
Uses this interaction so it magnetically
levitates or floats along and above the tracks.
So, friction between the train and its tracks is
virtually non-existent.
its

• very high speed
• reliability
• safety
• minimum maintenance
• low environmental impact

Advantages
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The EMS system
-uses attraction
- superconductors induce current in coils,
producing electromagnets. Energised
electromagnets attracted up to iron rails on
guideways edges.
- electromagnets of like polarity are in guideway
and train, these are repelled, lifting the train.
2 different types of maglev systems
- other guidance magnets are embedded in train
body, keeping it stable.
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acceleration for both systems
Achieved by continually changing polarity of
alternate magnets along the track, creating a
series of attractions and repulsions, providing
accelerating force.
The magnets and the coils act like two like
poles resulting in a repulsion between the two
so the train is lifted off the guideway.
It uses the meissner effect, with superconducting
magnets on the train and the electrically
conductive strips or coils in the guideway.
- uses repulsion
The EDS system
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MRI machines

• Provide doctors with 3D images of internal
  structure of human body.
• Strong magnetic field provided by a
  superconductor applied to body.
• H atoms in bodys water and fat forced to accept
  energy then release it for computer
  processing.

Computers powerful computers which are able to
process all the data have had to be developed.
Positively influenced, increased and furthered
computer development.
Effects
Energy is not being lost, so once desired
magnetic field strength is achieved no further
energy imput is required (unlike normal
solenoids). So this has a positive effect on
electrical transmission, motors and generators.
As relatively not much energy is required and
heat is not being produced.
Further applications of superconductors
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• extremely sensitive
• use Josephson effect to detect tiny magnetic
  fields
• used-in geophysics
• -to make magnetograms of brain/heart

SQUIDs
Josephson effect
Electrons able to travel across insulator, with
superconducting material either side, as cooper
pairs.
Can be used in superfast switches. Further
improving computers as the superconducting
switching devices can operate at speeds up to 10
times the speed of a semiconductor switch.
Further applications of superconductors
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Other applications in the following areas are all
advantageous, providing further developments and
extremely positive effects on the areas.
Electricity transmissions energy losses caused
by wires resistance. If superconducting wires
used energy would be saved, 3-5 times more
current carried, long distances not an issue-
power stations in remote locations, reduced cost
of power and demand for new power stations.
Motors and generators superconducting wire is
more efficient than copper wire. - fraction of
size and mass - less fossil fuels required
Power storage SMES means electricity doesnt
have to be used immediately. Stored in wires and
no electrical heat energy will be lost.
Further applications of superconductors
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Light gathering power of a telescope
sEnSiTiViTy
OR
Telescopes
Its ability to pick up faint objects
Sensitivity depends upon collecting area of lens
or mirror
Collecting area depends on diameter of lens or
mirror
Larger diameter
d
d
Larger collecting area
Sensitivity increased
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• depends upon wavelength of light being collected
  and the size of the aperture- diameter of the
  lens or mirror.

Larger diameter more sensitive improved
resolution
A good telescope design (large diameter lens or
mirror), limits aberrations- faults/imperfections
which cause a point object to appear as a blob.
A larger diameter objective lens or mirror is
desirable- resolution is better, thus image is
clearer.
ReSoLuTiOn
Ability of telescope to distinguish between two
very close objects.
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Adaptive optics measures and compensates for
atmospheric effects. Incident light ray (e.g from
a star) sampled- measuring atmospheric
distortion. Information processed, mirrors
adjusted, image is undistorted.
Active optics measures and compensates for
imperfections in mirror. Works slower than
adaptive optics. Light sampled, signals sent and
actuators on back of mirror push or pull it into
the correct shape, correcting sagging and other
deformaties.
New generation optical telescopes
Interferometryunblurs images received by
optical telescopes. Uses 2/more telescopes and
combines their signals. Resolution power
Telescopes x distance aparttelescope with x
diameter
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The end
H. Kamerlingh-Ohnes a.k.a max plancks uncle willy