Transcript HEP in the Classroom

HEP in the Classroom
Dr. Sascha Schmeling
CERN/EP
HST Programme 2001
Overview
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Particle Physics as a Subject in Schools
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Popular School Experiments
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Cosmic muon detection
Short Discussion
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CRT, e/m, Millikan
Self-built Experiments
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Example for a curriculum
available experiments
existing knowledge
Hands-on Workshop
Curriculum
Repetition of known experiments
1.
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3.
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5.
Cathode Ray Tube, Millikan, e/m
Work with an interactive system
many systems
Discuss found problems,
already available
Work on specific topics
2.
4.
if not, it is
a good
opportunity!!!
Homework: Preparation of Short Talks
Talks, Q&A
“Own” experiment, Outlook,
Links to other subjects
Feynman diagrams,
various experiments
Cloud Chamber
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mostly known for
nuclear physics
experiments
principle
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see the name
possible experiments
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visualisation of
elementary particles
Rutherford’s Experiment
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scattered beams
241Am
primary
a beam
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gold foil
detector
THE experiment to
show that matter on
our scales has a
substructure
principle
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scattering
Cathode Ray Tube
vacuum tube
acceleration voltage
cathode
anode
electron beam
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well-known experiment,
with screen useable for
various effects
principle
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acceleration with
electrical fields
deflection with different
field types
Electron Beam Diffraction Tube
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not really particle physics but
good possibility to show the
wave nature of electrons
principle
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Bragg reflection at graphite
electron waves
possible experiments:
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wave length measurement
h measurement
Millikan Experiment
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classical experiment
(first performed 1916)
to show quantisation of
the electrical charge
principle:
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electric force
possible experiment:
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measurement of
electron charge
Multimedia Tools
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Some of these experiments cannot be shown
in every school, as they are expensive.
Pupils always
use computers!
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Why not use multimedia for this?
Sure, but there is the need – sometimes!
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Blackexist
box!many
There
ready-to-use applets
even from teachers
for teachers!
Anyway, one
should restrict
that!
Example: Millikan-Experiment with ViMPS
Fine Beam Tube
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instructive
measurement of
electron properties
principle:
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Lorentz Force
possible experiment:
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measurement of e/m
e/m Experiment
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Theoretical input:
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Measurement:
F Lorentz  B  e  v
Fcenter 
E kin 
1
2
m v
U
[V]
2
r
 m  v , E electric  e  U accel .
2

m v 
2
e U
2
e
m

2 U
B r
2
2
B
[T]
r
[cm ]
e/m
11
[10 C/kg]
Circular
e/m ? Accelerator
magnetic
field
r
cathode
electron beam
accel. voltage
Franck-Hertz Experiment
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also not a real “particle
physics” experiment
but good to show
quantisation
principle:
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ionisation by electrons
possible experiment:
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illustrate Bohr’s model
Self-Made Experiments
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In contrast to these – expensive – standard
experiments, it is possible to set up small
experiments with available or not expensive to buy
pieces, such as
KamioCan
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coffee pots
neon tubes
wire
Muon detection
small spark chamber
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with these tools it is possible to perform nice
experiments with cosmic muons
KamioCan
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small experiment to detect
muons
simple set-up
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power supply
oscilloscope
photomultiplier
pot
with large(r) pot you can
measure the muon lifetime
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PC needed
documented electronics
Muon Lifetime
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expected signal from
photomultiplier
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background (non-m)
m- +background
m+
for unfolding one could
fit a function and
derive the muon
lifetime:

f (t )  e

t
only use
for t>~2ms
Nice to relate
to mathematics!?
Neon Tubes
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another small experiment
to detect cosmic muons
very simple set-up
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neon tubes (even faulty
ones)
power supply
adjustable to your
needs/wishes
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granularity
efficiency
Questions?!
The
End
See you
at the
workshop!