Phase Contrast Aberration Corrected Electron Microscope for Phase Plate Imaging

Abstract

Extended abstract of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 – August 5, 2010.

Retrofit implementation of Zernike phase plate imaging for cryo-TEM

“…Although progress is being made to reduce the size of the central element (Chen et al, 2008; Shiue et al, 2009, Alloyeau et al, 2010), the current remedy for excessive low-frequency blocking is to use a modified TEM that has one or more extra lenses to magnify the diffraction plane where the phase plate is inserted (e.g. Majorovits et al, 2010). This ameliorates problems with extreme miniaturization of the electrostatic element.…”

Phase plates in the transmission electron microscope: operating principles and applications

“…The early successes of thin-film type ZPP devices led to extensive efforts to correct for its imaging artifacts and to develop new types of devices, e.g. the Börsch PP (Table 3) [21,22,25,62,88,[217][218][219]. We briefly review the progress in the application of PP imaging in TEM to biological samples focusing on HFPP applications.…”

“…The implementation of a thin aC film with a small hole in the BFP is very similar to the proposal of Zernike and thus has been termed the Zernike phase plate (ZPP) [19]. Its success enticed researchers to investigate other kinds of phaseshifting devices that include the electrostatic Börsch-PP [20][21][22][23][24][25][26] and its derivatives [27,28] as well as other more exotic types [29][30][31]. In addition to thin-film and electrostatic devices, PPs that exploit other means of interactions, e.g.…”

Optimized In-Focus Boersch Phase Contrast in a Dedicated TEM

“…We solved the problem of low-frequency obstruction by positioning a Boersch phase plate in a 5-fold magnified diffraction plane of a corrected 200 kV TEM dedicated to low-dose cryo imaging. The prototype Phase Contrast Aberration Corrected EM (PACEM) has an effective focal length of ~15 mm [5], which decreases the cut-on frequency to d/10λf (Table 1). The CS corrector, monochromator and energy filter are used to compensate the increase in lens aberrations.…”