Practical Group Practical Group Teachers Lab Teachers Lab At At CERN CERN Jana Buresova Jana Buresova Marla Glover Marla Glover Claudia Haagen-Schützenhöfer Claudia Haagen-Schützenhöfer Alexander Kraft Alexander Kraft
Practical GroupPractical Group
Teachers LabTeachers Lab
At At
CERNCERN
Jana Buresova Jana Buresova
Marla Glover Marla Glover
Claudia Haagen-Schützenhöfer Claudia Haagen-Schützenhöfer
Alexander KraftAlexander Kraft
Teachers lab at CERNTeachers lab at CERN
• General concept
• Demonstration
• Equipment
• Cost
Where should the lab be?Where should the lab be?
• It should be a fixed installation (room, lab, etc…)
• Near Microcosm – First choice
• Near the Training Center – second choice
• Very near a Equipment Storage area
• Near a workshop area
Who should us it?Who should us it?
• It could become apart of existing teacher programs( HST, workshops, visits, etc…)
• Create a program just to use for labs – An extension of programs– A follow-up program to existing programs
• Teachers with a class of students– They would need to have passed a CERN
training program to run the equipment and know and understand CERN procedures
What should the lab look like?What should the lab look like?
• Ideal– Classroom with lab space and terminals– Attached storage area– Attached workshop
classroom
lab storage
workshop
What should the lab look like?What should the lab look like?
• Next best– Classroom with large demonstration area– Presentation Equipment– Storage nearby
Look at other particle labsLook at other particle labs
DESY – workshops for students and teachers
in special lab (experiments with
radioactivity, vacuum and cosmic rays)
Also demonstrational experiments: Photoeffect, Comptoneffect, Röntgenspectrum …
Look at the other particle labsLook at the other particle labs
FERMILAB Lederman Science Center
Look at the other particle labsLook at the other particle labs
FermilabFermilab
• Educational center for both students and teachers• Workshops for students and pupils with hands-on experiments• Programmes not only about particle physics• Wide offer of different types of visits (1-day to 1-week)
Equipment for Equipment for Teacher’s Lab to show:Teacher’s Lab to show:
I. Structure of matter and basic properties of elementary particles
II. Particle acceleration
III. Particle detection
Rutherford ExperimentRutherford Experiment
• WHAT? – Historic experiment to investigate the structure of matter– Scattering -spectroscopy
• HOW?– A beam of - particles is scattered against gold sheet.– The intensity at different angles hints to structure of atoms.
• WHY?– Investigate the internal structure of particles – To understand early methods of determining properties– Scattering (fixed target experiment) is a method to do
particle physics (particle production, detection …)
Millikan ExperimentMillikan Experiment
• WHAT? – Historic experiment to determine the charge of an
elcetron– Electric field– Measurement of e/m
• HOW?– An electric field and gravity acts on charged oil
droplets at the same time in opposite directions.– The elementary charge is determined from the
velocity of the oil-drop movement.
• WHY?– Mass and charge are important particle properties
Stern-Gerlach ExperimentStern-Gerlach Experiment
• WHAT? – Historic experiment to prove the existence of electron spin– Magnetic moment– Directional quantization
• HOW?– A beam of potassium atoms is deflected in a non-uniform
magnetic field because of the magnetic moment of the atoms.
– Magnitude and direction of the magnetic moment of the atoms are obtained by measuring the density of the beam.
• WHY?– Electron spin and magnetic moment are important
properties of elementary particles
Zeemann EffectZeemann Effect
• WHAT? – Quantization of energy levels– Electron spin– Bohr’s magneton– Interference of magnetic wave
• HOW?– A cadmium lap is submitted to different magnetic flux
densities.– The red cadmium line is splitted.
• WHY?– Show basic properties of particles– Methodology used in Cosmology
Electron spin resonanceElectron spin resonance
What?_ Energy quantum_ Quantum number_ Resonance_ g-factor
Cathode Ray TubeCathode Ray Tube
• WHAT? – Linear propagation of electron beams– Behaviour of electrons in electric fields– Deflection of electrons in magnetic fields (Lorentz-Force)
• HOW?– Electrons are accelerated within electric fields.– The electron beam is deflected by magnets.
• WHY?– Electric fields are used for acceleration– Magnetic fields are used for bending beams in accelerators– The change of trajectories due to magnetic fields is one
principle of measurement in detectors
Thomson’s experiment Thomson’s experiment
• WHAT? – Energy gain due to electric field– Trajectory curvature due to magnetic field (Lorentz)– Properties of electrons (charge, mass)
• HOW?– Electrons accelerated in an electric field and enter a perpendicular
magnetic field.– e/m is determined from accelerating voltage, magnetic field strength and
radius of the orbit.
• WHY?– Electric fields are used for acceleration– Magnetic fields are used for bending beams in accelerators– The change of trajectories due to magnetic fields is one principle of
measurement in detectors
Electron beam diffractionElectron beam diffraction
• WHAT? – Material waves– De Broglie equation– Bragg reflection– Calculation of electron velocity
• HOW?– Accelerated electrons hit a polycrystalline layer of graphite.– The interference pattern is displayed on a flourescent
screen.
• WHY?– The wave-nature of particles plays a role in acceleration – Scattering (fixed target experiment) is one method to do
particle physics
SuperconductivitySuperconductivity
• WHAT? – Determine transmission temperature– Meissner-Ochsenfeld-Effect
• HOW?– The temperature of the superconductor is constantly
lowered.– Temperature and resistance are measured in short
time intervals.
• WHY?– Superconductors are important for the creation of
accelerators and detectors
Hall EffectHall Effect
• WHAT? – Strength of the magnetic field– Magnetic moment– Directional quantization
• HOW?– A current carrying conductor is placed in a magnetic
field.– A small transverse potential difference (Hall-voltage)
can be determined.
• WHY?– Magnetic fields of a certain flux play an important role
in many steps of CERN experiments (acceleration, detection ...)
Magnetic Nuclear ResonanceMagnetic Nuclear Resonance
• WHAT? – Strength of the magnetic field– Magnetic moment– Directional quantization
• HOW?– Magnetic moments are aligned with an external magnetic
field and this alignment is perturbed by an electromagnetic field.
– The response to the field by perturbing is what is exploited in nuclear magnetic resonance spectroscopy.
• WHY?– Precision measurement of magnetic fields is done by NMR at
CERN
Photoelectric EffectPhotoelectric Effect
• WHAT? – Work function– Photon energy– Quantization of energy
• HOW?– A negatively charged zinc plate on top of an electroscope
is illuminated with a high pressure mercury lamp.– The zinc plate is discharged if there is no barrier
(plexiglass) in between.
• WHY?– Excitation by collision and emission of photons afterwards
is one principle of measurement in detection
Myon experiencesMyon experiencesWHAT?
– Measure properties of muons– Observe decays
HOW?– Cloud chamber (Workshop or Equipment)– KamioCan (HST 2000)– Experiments done by practical WorkingGroup
QUARKNET
• WHY?– Usage of cosmic rays for calibration of detectors
Frank-Hertz Experiment (Neon)Frank-Hertz Experiment (Neon)
• WHAT? – Energy quantum– Electron collision– Excitation energy
• HOW?– Accelerated electrons excite neon gas electrons in a tube.– The electrons in neon at upper states de-excite in such a way
as to produce a visible glow in the gas.
• WHY?– The quantization of energy states in atoms are visualized– Excitation / Scintillation is one principle of measurement in
detection
Electron Positron SpectroscopyElectron Positron Spectroscopy
• WHAT? - - decay + - decay– Positron– Neutrino– Resting energy– Decay energy– Relativistic Lorentz equation
• HOW? -radiation of unstable nuclei is selected on the basis
of its pulses in a magnetic transverse field using a diaphragm system.
– The relationship between coil current and particle energy is determined for calibration of the spectrometer.
– And the decay energy of -transition is obtained in each case from the - -spectra.
• WHY?– Resting and decay energy are important properties of
particles– Spectroscopy is an important analytical method
CostCost
• Leybold Didactic Swiss-75,000chf– Minus 10% discount-67,000chf– Minus duplicates-59,000chf
• Phywe bid-113,000euros
• Room to negotiate
• Other sources of economy???
Electron Spin ResonanceElectron Spin Resonance
• What?– Magnus Effect/Magnetic Fields/Rotational
mechanics– Resonance/Spin Resonance
• How?– The magnetic moments align in the
permanent magnetic field.– The perpendicular alternating field creates
excitation which results in the electrons absorbing energy then releasing it when it goes back to its ground state.
• Why?– This will help students see how electron spin
is used in medicine and materials.