Hollow cone illumination for fast TEM, and outrunning damage with electrons. (23rd September 2015)

• Record Type: Journal Article
• Authors: Spence, J C H; Subramanian, G; Musumeci, P
• Is Part Of: Journal of physics. Volume 48:Number 21(2015:Nov. 01)
• Publication Date: 2015-09-23
• Subjects: femtosecond electron beams -- fast imaging -- radiation damage; Atoms -- Periodicals; Molecules -- Periodicals; Optics -- Periodicals; Nuclear physics -- Periodicals; 539.6
• DOI: 10.1088/0953-4075/48/21/214003
• Languages: English
• ISSNs: 0953-4075

Abstract

Abstract: We consider the possibility of imaging individual bioparticles using snapshot diffraction from femotsecond pulses, using a 3 MeV electron beam, based on the recent experimental performance of these coherent beams. Assuming that radiation damage can be outrun using 100 fs pulses (or less), we find that a sufficient number of electrons are scattered per particle only if the beam diameter can be matched to that of the particle (e.g. a virus), about three orders of magnitude smaller than has currently been demonstrated (and limited by space-charge effects). We then propose the use of the hollow-cone illumination mode for fast transmission electron microscope imaging, because it can provide full-field atomic resolution imaging despite the use of the large incoherent annular source required for an efficient photocathode, so that coherent illumination is not needed for high-resolution imaging. Reciprocity arguments are used to compare this full-field mode with data aquisition times and source brightness in scanning transmission electron microscopy.