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

THANK YOU FOR YOUR ATTENTION!