TY  - JOUR
AU  - Krause, Florian F.
AU  - Schowalter, Marco
AU  - Oppermann, Oliver
AU  - Marquardt, Dennis
AU  - Müller-Caspary, Knut
AU  - Ritz, Robert
AU  - Simson, Martin
AU  - Ryll, Henning
AU  - Huth, Martin
AU  - Soltau, Heike
AU  - Rosenauer, Andreas
TI  - Precise measurement of the electron beam current in a TEM
JO  - Ultramicroscopy
VL  - 223
SN  - 0304-3991
CY  - Amsterdam
PB  - Elsevier Science
M1  - FZJ-2021-02888
SP  - 113221 -
PY  - 2021
N1  - Bitte Post-print ergänzen
AB  - Modern quantitative TEM methods such as the -factor technique require precise knowledge of the electron beam current. To this end, a macroscopic Faraday cup was designed and constructed. It can replace the viewing screen in the projection chamber of a TEM and guarantees highly accurate measurement of the electron beam with precision only limited by the used amperemeter. The easy to install, affordable device is shown to be highly apt for precision measurement of currents . The Faraday cup results are used for an assessment and a comparison of various other beam current measurement methods. It is found that the built-in screen amperemeter of the used TEM is quite inaccurate and that measurements using the screen in general tend to underestimate the current. If present, the drift tube of a spectrometer can also be used as a Faraday cup, but certain described peculiarities have to be taken into account. Direct ultrafast electron detection cameras allow precise measurement at very small currents. For the electron counting technique, which exploits single electron detection capabilities of STEM detectors, a systematic current underestimation was observed and investigated. This results in a reformulated routine for the method and with these improvements it is demonstrated to be capable of accurate high-precision measurements for currents
LB  - PUB:(DE-HGF)16
C6  - 33588232
UR  - <Go to ISI:>//WOS:000632279200008
DO  - DOI:10.1016/j.ultramic.2021.113221
UR  - https://juser.fz-juelich.de/record/893876
ER  -