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CPO TS – 2 nd ERASMUS Intensive Program Introduction to C harged P article O ptics: T heory and S imulation. http://cpots2012.physics.uoc.gr Dept. of Physics, University of Crete Aug 19 – Sept 2, 2012 Heraklion, Crete, GREECE.
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CPOTS – 2nd ERASMUS Intensive ProgramIntroduction to Charged Particle Optics: Theory and Simulation http://cpots2012.physics.uoc.gr Dept. of Physics, University of Crete Aug 19 – Sept 2, 2012 Heraklion, Crete, GREECE CPOTS 2013: 3rd ERASMUS IP on Charge Particle Optics – Theory and Simulation Dept. of Physics, University of Crete, Heraklion, GREECE Project Coordinator: Prof. Theo Zouros (tzouros@physics.uoc.gr)
Group Project Magnetic Bottle Electron Spectrometer Nimet Okumuş Socrates Anastasopoulos David AlcocerVelarde http://cpots2012.physics.uoc.gr
Abstract • The principles of magneticbottlemass spectrometer • Theoreticalanalysis • Energyresolution of magneticbottlespectrometer • Conclusions
Magnetic Bottle Electron Spectrometer The use of permanent magnets requiresmodifications of the transition region (between the high-field electron production zone and thelow-field drift tube analyzer) to avoid axial field reversals associated with fringing fields. Weak uniform B field e- Strong B field Analyser e- • Electrons spiral in B field which reduces adiabatically • Electron energy measured by time of flight to detector • Lets use a standard spectrometer, e.g. hemispherical analyser with an entrance aperture • Very small solid angle, most electrons lost! • 4 collection of electrons e- e-
Investigate Spectrometer Properties • Measure the time of flight for electrons with different conditions (using Record function) • Find the energy resolution of the spectrometer in differentsituation
SIMION Magnetic Bottle Spectrometer ParticlesDefinition
SIMION Magnetic Bottle Spectrometer FlyingParticles Threedifferentgroupwithenergy40, 20, 5 eV
SIMION Modelling of Magnetic Bottle Spectrometer Fromthis 2 equationsweexportedtherelationbetweenKineticEnergyand TOF K is constant. EnergyResolution of Spectrometer 8
SIMION Magnetic Bottle Spectrometer Bi=2000 gauss Bf=10 gauss TransitionRegion=9 mm Calibrationfactor=KE×(TOF)2 K=0.179574 eV µsec²
Convertion TOF to KE TOF KE
Magnetic Bottle SpectrometerResolution The resolution of the Spectrometer is: 10%
Energyresolution = 19.75 eV/(20.6-18.6) eV ≈10% Energyresolution = 9.95 eV/(10.4-9.4) eV ≈ 10% ΔKE ΔKE Energyresolutiondoesn’tdepend on KE. http://cpots2012.physics.uoc.gr
Resolution Resolution= 8.6/ (10.25-7.1)=2.7% Resolution= 9.6 / (10.35-8.9)=6.6% Bi= 3000 Gauss Bi=8000 Gauss ΔKE ΔKE http://cpots2012.physics.uoc.gr
Conclusion Resolution of spectrometer is depenton length of the time of flighttube. Theresolutionchangeswith B field . Energyresolutiondoesn’tdepend on KE. http://cpots2012.physics.uoc.gr