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Invention of the Bubble Chamber Invention of the bubble chamber Seminar talk 12. I. 2016 - Thomas Rudzki Inventer of the bubble chamber Donald A. Glaser (1926-2013) • Ph.D. at Caltech • Worked on cloud chambers with Anderson • Professor at Michigan • Invention of bubble chamber • Nobel Prize 1960 • Switching into molecular biology • Transition to neurobiology by wikipedia.org Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 2 “Improver“ of the bubble chamber Luis Walter Alvarez (1911-1988) • Discovery of many resonances • Hydrogen bubble chamber • Suggested theory for extinction of dinosaurs by www.gahetna.nl Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 3 Motivation Cloud Chamber • C. Wilson 1912 (NP 1927 with Compton) • Saturated vapor • Adiabatic expansion cools gas • Condensation at ionised tracks by DESY Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 4 Motivation Cloud Chamber • BUT: – Low denisty – Low rate • New accelerators with higher energies and rate by cloudylabs.fr Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 5 Motivation Why use superheated liquids? • Localised macroscopic disturbance • Metastable state; compare – Geiger counter, Cloud chamber • Metastability in liquid or solid due to density • Rapidly reversible changes and fast recycling • Easy readout, eg. photography • Superheated state of a pure liquid Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 6 Motivation How use superheated liquids? • Material: diethyl ether • Calculation: – @ 1atm and 140°C ionizing radiation causes boiling • Normal boiling point: @ 34.6°C • Physical chemist already analysed these conditions – Below 130°C for several hours – @ 140°C erratic eruptions (ν = 푚푛−1) • Boiling with controlled γ-ray source Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 7 Bubble chamber Set-up Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 8 Bubble chamber Set-up Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 9 Bubble chamber Theory of bubble creation • Young-Laplace equation 2휎 푝 = 푟 • Equilibrium pressure 푝푒 = 푝푔푎푠 − 푝푓푙푢푖푑 • Equilibrium radius 2휎 푅푒 = 푝푒 • Minimum energy 2 4휋 3 퐸 = 4휋휎푅 + 푅 푛 퐻 푚푖푛 푒 3 푒 휈 푠 Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 10 Bubble chamber Theory of bubble creation • Obtained values for Hydrogen and propane are 4 eV and 131 eV per 2푅푒 • Bubble counting and comparing with cross section gives a threshold energy of 0.5 keV and 1.9 keV per 2푅푒 • Not-relativistic electrons of this energy are stopped in region of 2푅푒 Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 11 Bubble chamber Gargamelle by nu.phys.laurentian.ca Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 12 Characteristic Features Electron & Positron Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 13 Characteristic Features Muon Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 14 Characteristic Features Proton and Neutron Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 15 Bubble chamber Photograph Analysis • Do an exemplary analysis on next slides • Get information from photographs – Momentum – Energy – Lifetime • Determined via – Length of tracks – Angle between tracks – Curvature of tracks Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 16 Bubble chamber Photograph Analysis • charged particles with curved tracks 푝 • 푅 = 푞 퐵 • ±푞: (anti-)clockwise • 푝 via curvature/radius Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 17 Bubble chamber Photograph Analysis • Our example: Σ production 퐾− + 푝 → Σ− + 휋+ • Interaction likely for small velocities • Σ− + 휋+ in pseudocontinous track Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 18 Bubble chamber Photograph Analysis • example: Σ production 퐾− + 푝 → Σ− + 휋+ • Interaction likely for small velocities • Σ− + 휋+ in pseudocontinous track Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 19 Bubble chamber Photograph Analysis • Interested in – 푝휋 – 푝Σ – 휃(Σ−, 휋−) • Determine lifetime 휏Σ and 푚푋 Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 20 Bubble chamber Photograph Analysis • First 푝휋 • 푝 = 푞푅퐵 2 2 2 푙 • 푅 = 푅 − 푠 − 2 푙2 1 푅 = + 푠 8푠 2 by www.wikipedia.org Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 21 Bubble chamber Photograph Analysis • 2nd: 푝Σ • No curvature calculation • Relation for Σ: 4 푝Σ 푑 = 0.597 174 1 푙Σ 4 • 푝 = 174 1 − Σ 0.597 Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 22 Bubble chamber Photograph Analysis • Angle between 훴− and 휋− 퐴퐵 = 180° − 휃 퐵퐶 Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 23 Bubble chamber Photograph Analysis • Mass of invisible (neutral) particle 푚푋 • Relativistic kinematics 2 2 2 퐸 = 푚 ; 퐸 = 푝 + 푚0 • Conservation laws for Σ− → 휋− + 푋0 푝푋 = 푝Σ − 푝휋 퐸푋 = 퐸Σ − 퐸휋 • From above 1 2 2 2 2 푚푋 = 퐸Σ − 퐸휋 − (푝Σ − 2푝Σ푝휋 cos 휃 + 푝휋 Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 24 Bubble chamber Photograph Analysis • Flight time of particle 푙Σ 푡 = 푣 • Comoving frame: 1 2 2 푙Σ 푣 푡′ = 1 − 푣 푐2 • Resulting in: 푚0푙Σ 푡′ = 푝Σ푐 Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 25 Bubble chamber Photograph Analysis −10 • 휏Σ = 1.46 ∙ 10 푠 compare to 1.49 ∙ 10−10푠 • 푚푋 = 915 푀푒푉 compare to neutron mass ≈ 940 푀푒푉 Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 26 Discoveries New unstable particles • Many new unstable particles could be found • Used simple calculation techniques as we did before • No explanation for many effects – Quark model not established yet by CERN Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 27 Discoveries New unstable particles • Example Ω−: – @Brookhaven 80 inch hydrogen chamber (1964) – Characteristic enough to identify Ω by CERN Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 28 Discoveries New unstable particles by hep.fsu.edu Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 29 Discoveries New unstable particles − • Example Ω : Characteristic signature – @Brookhaven 80 inch hydrogen chamber (1964) – Characteristic enough to identify Ω by CERN Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 30 Discoveries New unstable particles by CERN by CERN Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 31 Discoveries Weak Neutral Currents • Viable Theory of weak neutral currents was claimed • Experimental groups didn‘t consider existence at all at this time • Neutral current events? • Signal caused by neutron background? by inspirehep.net Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 32 Discoveries Weak Neutral Currents • Distinguish between: 휈 + 푁 → 휈 + ℎ푎푑푟표푛푠 휈 + 푁 → 휇 + ℎ푎푑푟표푛푠 • 3 categories (see right) • Background evaluation – Low momentum muons – Cosmic rays – Neutral hadrons • All in all, background can not describe measurement by Haidt et al. Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 33 Discoveries Quark-Parton-Model • Comparison of form factors 퐹2 for neutrino and electron scattering 2 • 퐹2 푥 = 푥 푗 푄푗 ∙ 푓푗 푥 2 2 2 1 퐹푒푝 푥 = 푥 푢 푥 + 푢(푥) + 푑 푥 + 푑(푥) 2 3 3 2 2 푒푛 2 1 퐹 푥 = 푥 푑 푥 + 푑(푥) + 푢 푥 + 푢(푥) 2 3 3 푒푁 5 • 퐹 푥 = 푥 푢 푥 + 푢 푥 + 푑 푥 + 푑 푥 2 18 풆푵 ퟓ 흂푵 • 푭 = 푭 ퟐ ퟏퟖ ퟐ Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 34 Discoveries Quark-Parton-Model Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 35 Nowadays WIMPs • Make bubble chamber “cool and cutting-edge“ • Superheated state for 80% of experiment time • 1 bubble events • Easy exchange of liquid • Contradiction to DAMA experiment • Upgrade from 1l to 30l by kicp.uchicago.edu chamber Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 36 Thank you, for your attention! Sources Paper, books: • Haidt et al. - OBSERVATION OF NEUTRINO-LIKE INTERACTIONS WITHOUT MUON OR ELECTRON IN GARGAMELLE NEUTRINO EXPERIMENT (1973) • Frederick Seitz - On the Theory of the Bubble Chamber • Donald A. Glaser - Nobel lecture • 45. Handbuch der Physik - Instrumentelle Hilfsmittel der Kernphysik 2 - Donald Glaser: The Bubble Chamber Internet: • http://www.physnet.org/modules/pdf_modules/m358.pdf • http://teachers.web.cern.ch/teachers/archiv/HST2005/bubble_chambers/BCWebsite/articles/probl em_30_mev.pdf • http://cerncourier.com/cws/article/cern/29168 • http://home.cern/about/experiments/gargamelle • http://www.symmetrymagazine.org/sites/default/files/legacy/pdfs/200808/deconstruction.pdf Seminar talk - Invention of the Bubble Chamber - Thomas Rudzki 37 .
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