Practical Group Teachers Lab At CERN Jana Buresova

Practical Group Teachers Lab At CERN Jana Buresova Marla Glover Claudia Haagen-Schützenhöfer Alexander Kraft

Teachers lab at CERN • • General concept Demonstration Equipment Cost

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? • 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? • Ideal – Classroom with lab space and terminals – Attached storage area – Attached workshop classroom lab storage

What should the lab look like? • Next best – Classroom with large demonstration area – Presentation Equipment – Storage nearby

Look 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 labs FERMILAB Lederman Science Center

Look at the other particle labs Fermilab • 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 Teacher’s Lab to show: I. Structure of matter and basic properties of elementary particles II. Particle acceleration III. Particle detection

Rutherford 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 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 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 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 resonance What? _ Energy quantum _ Quantum number _ Resonance _ g-factor

Cathode 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.

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

Electron 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

Superconductivity

• 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 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 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 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

WHAT? Myon experiences – Measure properties of muons – Observe decays HOW? – Cloud chamber (Workshop or Equipment) – Kamio. Can (HST 2000) – Experiments done by practical Working. Group QUARKNET • WHY? – Usage of cosmic rays for calibration of detectors

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 deexcite in such a way as to produce a visible glow in the gas.

Electron 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

Cost • Leybold Didactic Swiss-75, 000 chf – Minus 10% discount-67, 000 chf – Minus duplicates-59, 000 chf • Phywe bid-113, 000 euros • Room to negotiate • Other sources of economy? ? ?

Electron 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.