HEP in the Classroom
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Transcript HEP in the Classroom
HEP in the Classroom
Dr. Sascha Schmeling
CERN/EP
HST Programme 2001
Overview
Particle Physics as a Subject in Schools
Popular School Experiments
Cosmic muon detection
Short Discussion
CRT, e/m, Millikan
Self-built Experiments
Example for a curriculum
available experiments
existing knowledge
Hands-on Workshop
Curriculum
Repetition of known experiments
1.
3.
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
mostly known for
nuclear physics
experiments
principle
see the name
possible experiments
visualisation of
elementary particles
Rutherford’s Experiment
scattered beams
241Am
primary
a beam
gold foil
detector
THE experiment to
show that matter on
our scales has a
substructure
principle
scattering
Cathode Ray Tube
vacuum tube
acceleration voltage
cathode
anode
electron beam
well-known experiment,
with screen useable for
various effects
principle
acceleration with
electrical fields
deflection with different
field types
Electron Beam Diffraction Tube
not really particle physics but
good possibility to show the
wave nature of electrons
principle
Bragg reflection at graphite
electron waves
possible experiments:
wave length measurement
h measurement
Millikan Experiment
classical experiment
(first performed 1916)
to show quantisation of
the electrical charge
principle:
electric force
possible experiment:
measurement of
electron charge
Multimedia Tools
Some of these experiments cannot be shown
in every school, as they are expensive.
Pupils always
use computers!
Why not use multimedia for this?
Sure, but there is the need – sometimes!
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
instructive
measurement of
electron properties
principle:
Lorentz Force
possible experiment:
measurement of e/m
e/m Experiment
Theoretical input:
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
also not a real “particle
physics” experiment
but good to show
quantisation
principle:
ionisation by electrons
possible experiment:
illustrate Bohr’s model
Self-Made Experiments
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
coffee pots
neon tubes
wire
Muon detection
small spark chamber
with these tools it is possible to perform nice
experiments with cosmic muons
KamioCan
small experiment to detect
muons
simple set-up
power supply
oscilloscope
photomultiplier
pot
with large(r) pot you can
measure the muon lifetime
PC needed
documented electronics
Muon Lifetime
expected signal from
photomultiplier
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
another small experiment
to detect cosmic muons
very simple set-up
neon tubes (even faulty
ones)
power supply
adjustable to your
needs/wishes
granularity
efficiency
Questions?!
The
End
See you
at the
workshop!