Agreed!
Closes #12
(I realized we discussed this only via chat, but never here, so for the sake of completeness) We usually measure the beamcurrent at the EELS-drift-tube, but imho everywhere in the column will do (as long as one takes care not to "loose" any electrons). Unit is charge per second, so ampere.
definition for detector vs. waiting time?
Issue came up during the breakout on 2021-12-13
label: dead time
plural: dead times
acronym: T
definition:
definition_en: >
Time period during which no data can be acquired.
comments: >
This is often related to the detector specifics - because the system may be physically unable to record
a particle measurement due to it being busy processing the previously detected event.
sources: >
- https://www.iso.org/obp/ui/#iso:std:iso:23833:ed-2:v1:en
- https://www.iso.org/obp/ui/#iso:std:iso:15932:ed-1:v1:en
contributors: >
- Annika Strupp
- Oonagh Mannix
- Clemens Mangler
- Markus Kühbach
- Volker Hofmann
Issue came up during the breakout session 2021-12.13
typical orders of magnitude in TEM: nA to pA
probably related term: extraction voltage #45 (closed)
The term came up in the breakout room session on 2021-12-13
other used term: high voltage
Gun pressure might be related to beamcurrent #16 (closed)
I would go for chamber pressure, as this will most likely impact the sample.
label: dose
definition: Number which expresses the number of particles transitioning through a defined area during a defined time period.
comment: For a given experiment, the dose may be determined by the beam current, dwell time and illuminated area used in this experiment.
label: electron dose
definitions: A dose which expresses the number of electrons transitioning through a defined area during a defined time period.
would define as electrons per second
Comment by Rosella: We need to define if at sample or gun
Term raised in the meeting today.
The term is important when studying beam induced alteration of the sample
label: filament current
synonyms:
exact_synonyms: > source current
definition:
definition_en: >
Electrical current which is flows through the electron source.
comments:
comments: >
This is typically used for heating a source. The source (i.e. tungsten wire,
LaB_6 crystal, tungsten crystal) is the element from which electrons are emitted).
Higher filament currents will result in higher beam currents.
label: beam current
definition:
definition_en: >
Electrical current which flows along the beam path.
comments:
comments_en: >
The beam current most frequently consists of electrons, but may also consist of ions in
some cases. The beam current varies along the beam axis as electrons are filtered out.
The points at which beam current is measured varies between instruments and
manufacturer. The beam current an also be understood as beam flux times charge
of the individual particles.
label: beam flux
definition:
definition_en: >
Number of particles which flow within the beam per unit time.
comments:
comments_en: >
label: beam
definition:
definition_en: >
Stream or particles which flows from source to detector.
comments:
comments_en: >
label: beam path
definition:
definition_en: >
Axis along which the beam flows.
comments:
comments_en: >
label: electrical beam
synonyms:
exact_synonyms: >
- electron beam
definition:
definition_en: >
A beam which consists of electrons.
comments:
comments_en: >
To be added
label: emission current
synonyms:
exact_synonyms: >
- source current
definition:
definition_en: >
Electrical current which is exited from the source.
comments:
comments: >
Emission current can not be reliably measured as it varies with angle. It is typically measured
at the first anode. The value is an indicator associated with a particular instrument rather
than a dependable constant. It can also vary with manufacturer.
label: probe current
definition:
definition_en: >
Electrical current which arriving at the specimen.
comments:
comments:>
to be added.
additional terms to be defined (in this cluster):
Should we link to the issue for specimen: !9 (closed)