Electron microscope phase enhancement
Abstract
A microfabricated electron phase shift element is used for modifying the phase characteristics of an electron beam passing though its center aperture, while not affecting the more divergent portion of an incident beam to selectively provide a ninety-degree phase shift to the unscattered beam in the back focal plan of the objective lens, in order to realize Zernike-type, in-focus phase contrast in an electron microscope. One application of the element is to increase the contrast of an electron microscope for viewing weakly scattering samples while in focus. Typical weakly scattering samples include biological samples such as macromolecules, or perhaps cells. Preliminary experimental images demonstrate that these devices do apply a ninety degree phase shift as expected. Electrostatic calculations have been used to determine that fringing fields in the region of the scattered electron beams will cause a negligible phase shift as long as the ratio of electrode length to the transverse feature-size aperture is about 5:1. Calculations are underway to determine the feasibility of aspect smaller aspect ratios of about 3:1 and about 2:1.
- Inventors:
- Issue Date:
- Research Org.:
- Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
- Sponsoring Org.:
- USDOE
- OSTI Identifier:
- 1176366
- Patent Number(s):
- 7737412
- Application Number:
- 11/571,980
- Assignee:
- The Regents of the University of California (Oakland, CA)
- Patent Classifications (CPCs):
-
H - ELECTRICITY H01 - BASIC ELECTRIC ELEMENTS H01J - ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- DOE Contract Number:
- AC02-05CH11231
- Resource Type:
- Patent
- Resource Relation:
- Patent File Date: 2005 Jul 12
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 47 OTHER INSTRUMENTATION; 59 BASIC BIOLOGICAL SCIENCES
Citation Formats
Jin, Jian, and Glaeser, Robert M. Electron microscope phase enhancement. United States: N. p., 2010.
Web.
Jin, Jian, & Glaeser, Robert M. Electron microscope phase enhancement. United States.
Jin, Jian, and Glaeser, Robert M. Tue .
"Electron microscope phase enhancement". United States. https://www.osti.gov/servlets/purl/1176366.
@article{osti_1176366,
title = {Electron microscope phase enhancement},
author = {Jin, Jian and Glaeser, Robert M.},
abstractNote = {A microfabricated electron phase shift element is used for modifying the phase characteristics of an electron beam passing though its center aperture, while not affecting the more divergent portion of an incident beam to selectively provide a ninety-degree phase shift to the unscattered beam in the back focal plan of the objective lens, in order to realize Zernike-type, in-focus phase contrast in an electron microscope. One application of the element is to increase the contrast of an electron microscope for viewing weakly scattering samples while in focus. Typical weakly scattering samples include biological samples such as macromolecules, or perhaps cells. Preliminary experimental images demonstrate that these devices do apply a ninety degree phase shift as expected. Electrostatic calculations have been used to determine that fringing fields in the region of the scattered electron beams will cause a negligible phase shift as long as the ratio of electrode length to the transverse feature-size aperture is about 5:1. Calculations are underway to determine the feasibility of aspect smaller aspect ratios of about 3:1 and about 2:1.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Jun 15 00:00:00 EDT 2010},
month = {Tue Jun 15 00:00:00 EDT 2010}
}