Practical Group Teachers Lab AtCERN Jana Buresova Marla Glover Claudia Haagen-Schützenhöfer 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.