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!