## ESEM Science and Technology

# BEAM TRANSFER CALCULATOR

## Definitions and terminology

References: Figure
of merit for environmental SEM and its implications
and
Optimum
beam transfer in the environmental scanning electron microscope
## CALCULATOR (*)

(*) Software supplied courtesy Daniel Danilatos

(Calculation log:)
Result:

pD values at which gas flow properties have been computed and fitted with curves below:

Accelerating voltage for sigma (scattering cross-sections) in next table

#### ARGON

Coefficients 1 for calculation of zeta in the range -4 to 0 diameters below the aperture

Coefficients 2 for calculation of zeta in the range 0 to 20 diameters above the aperture

Coefficients 3 for calculation of normalised density in the range -4 to 0 diameters below the aperture

Coefficients 4 for calculation of normalised density in the range 0 to 20 diameters above the aperture

Sigma used (scattering cross-sections) for the accelerating voltages in previous table

Coefficients 5 for calculation of leak rate hrough aperture

#### NITROGEN

Coefficients 1 for calculation of zeta in the range -4 to 0 diameters below the aperture

Coefficients 2 for calculation of zeta in the range 0 to 20 diameters above the aperture

Coefficients 3 for calculation of normalised density in the range -4 to 0 diameters below the aperture

Coefficients 4 for calculation of normalised density in the range 0 to 20 diameters above the aperture

Sigma used (scattering cross-sections) for the accelerating voltages in previous table

Coefficients 5 for calculation of leak rate hrough aperture

#### HELIUM

Coefficients 1 for calculation of zeta in the range -4 to 0 diameters below the aperture

Coefficients 2 for calculation of zeta in the range 0 to 20 diameters above the aperture

Coefficients 3 for calculation of normalised density in the range -4 to 0 diameters below the aperture

Coefficients 4 for calculation of normalised density in the range 0 to 20 diameters above the aperture

Sigma used (scattering cross-sections) for the accelerating voltages in previous table

Coefficients 5 for calculation of leak rate hrough aperture

#### HYDROGEN

Coefficients 1 for calculation of zeta in the range -4 to 0 diameters below the aperture

Coefficients 2 for calculation of zeta in the range 0 to 20 diameters above the aperture

Coefficients 3 for calculation of normalised density in the range -4 to 0 diameters below the aperture

Coefficients 4 for calculation of normalised density in the range 0 to 20 diameters above the aperture

Sigma used (scattering cross-sections) for the accelerating voltages in previous table

Coefficients 5 for calculation of leak rate hrough aperture

#### WATER_VAPOR

Coefficients 1 for calculation of zeta in the range -4 to 0 diameters below the aperture

Coefficients 2 for calculation of zeta in the range 0 to 20 diameters above the aperture

Coefficients 3 for calculation of normalised density in the range -4 to 0 diameters below the aperture

Coefficients 4 for calculation of normalised density in the range 0 to 20 diameters above the aperture

Sigma used (scattering cross-sections) for the accelerating voltages in previous table

Coefficients 5 for calculation of leak rate hrough aperture

#### Oxygen

Coefficients 1 for calculation of zeta in the range -4 to 0 diameters below the aperture

Coefficients 2 for calculation of zeta in the range 0 to 20 diameters above the aperture

Coefficients 3 for calculation of normalised density in the range -4 to 0 diameters below the aperture

Coefficients 4 for calculation of normalised density in the range 0 to 20 diameters above the aperture

Sigma used (scattering cross-sections) for the accelerating voltages in previous table

Coefficients 5 for calculation of leak rate hrough aperture

#### Neon

Coefficients 1 for calculation of zeta in the range -4 to 0 diameters below the aperture

Coefficients 2 for calculation of zeta in the range 0 to 20 diameters above the aperture

Coefficients 3 for calculation of normalised density in the range -4 to 0 diameters below the aperture

Coefficients 4 for calculation of normalised density in the range 0 to 20 diameters above the aperture

Sigma used (scattering cross-sections) for the accelerating voltages in previous table

Coefficients 5 for calculation of leak rate hrough aperture

## ESEM Science and Technology