Journal Article

FZJ-2021-02888

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Precise measurement of the electron beam current in a TEM

Krause, F. F. (Corresponding author) ; Schowalter, M. ; Oppermann, O. ; Marquardt, D. ; Müller-Caspary, K.FZJ* ; Ritz, R. ; Simson, M. ; Ryll, H. ; Huth, M. ; Soltau, H. ; Rosenauer, A.

2021
Elsevier Science Amsterdam

This record in other databases:    

Please use a persistent id in citations: http://hdl.handle.net/2128/28578  doi:10.1016/j.ultramic.2021.113221

Abstract: 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

Note: Bitte Post-print ergänzen

---

Contributing Institute(s):

1. Physik Nanoskaliger Systeme (ER-C-1)

Research Program(s):

1. 5351 - Platform for Correlative, In Situ and Operando Characterization (POF4-535) (POF4-535)
2. moreSTEM - Momentum-resolved Scanning Transmission Electron Microscopy (VH-NG-1317) (VH-NG-1317)

Appears in the scientific report 2021

---

Database coverage:
; ; BIOSIS Previews ; Biological Abstracts ; Clarivate Analytics Master Journal List ; Current Contents - Life Sciences ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; Essential Science Indicators ; IF < 5 ; JCR ; Nationallizenz ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

---