45° Tandem Parallel Plate Analyser
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Transcript of 45° Tandem Parallel Plate Analyser
45° TANDEM PARALLEL PLATE ANALYSERSIMION PROJECT
Louise BelshawSpiros Divanis
Patrik GunackerPeter Herczku
PPA ONE
PPA TWO
IONS, ELECTRONS IONS
ELECTRONS
SIMION Project: Tandem PPA Analyser
SIMION Project: Tandem PPA Analyser
`Tandem Parallel Plate Analyser:
• Build a simple tandem PPA, consisting of two PPAs placed at 90°.• Investigate required voltages and angles of acceptance.
• Add an Einzel lens before the input slit of PPA1, and place another between the exit of PPA1 and the entrance of PPA2.• How does this change our results?
SIMION Project: Tandem PPA Analyser
`SIMION Project: Tandem PPA Analyser
SIMPLE TANDEM PPA
PPA ONE
PPA TWO
0
0i
PASSii0d
L)2(Sind2f
EfVV
For this PPA, f = 0.6Electrons of KE = 1000 eVExpect required V = -600 VUsed: -597 V
SIMION results
Required Deflecting voltage:
Acceptance Solid Angle:
Transmission:
α = ± 3°β = ± 5°Ω = 4αβ = 0.018 steradians
Strong angular dependence:With α = 3, β = 5, T = 0.2 % α = 1, β = 1, T = 3 %
SIMION Project: Tandem PPA AnalyserSIMION Project: Tandem PPA Analyser
SIMPLE TANDEM PPATypical Particle Definitions:
SIMION Project: Tandem PPA Analyser
TANDEM PPA WITHOUT FOCUSSING
SIMION Project: Tandem PPA Analyser
`TANDEM PPA WITH EINZEL LENS
EINZEL LENS 1
EINZEL LENS 2
SIMION Project: Tandem PPA Analyser
`TANDEM PPA WITH EINZEL LENS
TANDEM PPA WITH EINZEL LENSSIMION Project: Tandem PPA AnalyserSIMION Project: Tandem PPA Analyser
Voltages:
Transmission:
With α = 3, β = 5, T = 5 % α = 1, β = 1, T = 30 %
SIMION Project: Tandem PPA Analyser
`TANDEM PPA WITH DECELERATION AND FOCUSSING
SIMION Project: Tandem PPA Analyser
`TANDEM PPA WITH DECELERATION AND FOCUSSINGVoltages:
Transmission:
With α = 3, β = 5, T = 0.4 % α = 1, β = 1, T = 9.2 %
SIMION Project: Tandem PPA Analyser
TRANSMISSION COMPARISON
PPA Type Transmission, α = 3, β = 5 Transmission, α = 1, β = 1
No focussing 0.2 3
Focussing 5 30
Focussing and deceleration
0.4 9.2
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