CPOTS 2013: 3 rd ERASMUS IP on Charge Particle Optics – Theory and Simulation Dept. of Physics, University of Crete, Heraklion, GREECE Project Coordinator: Prof. Theo Zouros CPOTS – 2 nd ERASMUS Intensive Program Introduction to Charged Particle Optics: Theory and Simulation Dept. of Physics, University of Crete Aug 19 – Sept 2, 2012 Heraklion, Crete, GREECE

2 Group Project Magnetic Bottle Electron Spectrometer Nimet Okumuş Socrates Anastasopoulos David Alcocer Velarde

3 Abstract The principles of magnetic bottle mass spectrometer Theoretical analysis Energy resolution of magnetic bottle spectrometer Conclusions

4 Magnetic Bottle Electron Spectrometer 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 Weak uniform B field Strong B field The use of permanent magnets requires modifications of the transition region (between the high-field electron production zone and the low-field drift tube analyzer) to avoid axial field reversals associated with fringing fields. e-e- e-e- e-e- e-e- Analyser

5 Investigate Spectrometer Properties Measure the time of flight for electrons with different conditions (using Record function) Find the energy resolution of the spectrometer in different situation

SIMION Magnetic Bottle Spectrometer Particles Definition

SIMION Magnetic Bottle Spectrometer Flying Particles Three different group with energy 40, 20, 5 eV

8 S IMION Modelling of Magnetic Bottle Spectrometer Energy Resolution of Spectrometer K is constant. From this 2 equations we exported the relation between Kinetic Energy and TOF

SIMION Magnetic Bottle Spectrometer B i =2000 gauss B f =10 gauss Transition Region=9 mm K= eV µsec² Calibration factor=KE×(TOF) 2

Convertion TOF to KE TOF KE

Magnetic Bottle Spectrometer Resolution The resolution of the Spectrometer is: 10%

CPOTS 2012: S9 - JBG 12/XX ΔKE Energy resolution = eV/( ) eV ≈10% ΔKE Energy resolution = 9.95 eV/( ) eV ≈ 10% Energy resolution doesn’t depend on KE.

CPOTS 2012: S9 - JBG 13/XX Resolution= 9.6 / ( )=6.6% B i = 3000 Gauss ΔKE B i =8000 Gauss ΔKE Resolution= 8.6/ ( )=2.7% Resolution

CPOTS 2012: S9 - JBG 14/XX Conclusion Resolution of spectrometer is depent on length of the time of flight tube. The resolution changes with B field. Energy resolution doesn’t depend on KE.