Humidified imaging with an environmental scanning electron microscope
AssigneeBallard Power Systems Inc.
InventorsFrancesco P. Orfino, Joerg Zimmermann, Lynn C. Erickson
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Abstract
A method and apparatus are described for imaging wet samples with an Environmental Scanning Electron Microscope (ESEM). In particular, a carrier gas is humidified such that the water vapor in the carrier gas in the sample chamber of the ESEM has a partial pressure equal to the saturated vapor pressure of water. Thus, the sample can be imaged without observing any evaporation or condensation thereon. Both the carrier gas and the water vapor may act as the imaging gas within the ESEM. The apparatus is an imaging gas delivery system for the ESEM wherein the carrier gas may be appropriately humidified.
Claims21
A method of operating an environmental scanning electron microscope at an operating temperature and an operating pressure within a sample chamber in the environmental scanning electron microscope, the method comprising:
- placing a sample in the sample chamber;
- humidifying a carrier gas such that the partial pressure of water vapor in the carrier gas corresponds to the vapor pressure of water at the operating temperature and the operating pressure;
- and
- operating the environmental scanning electron microscope with the humidified carrier gas as the imaging gas.
An imaging gas delivery system for an environmental scanning electron microscope having a gas inlet, the system comprising:
- a carrier gas supply;
- a gas humidifier coupled to the carrier gas supply;
- a humidity sensor coupled to the gas humidifier;
- and
- a delivery valve adapted to receive the gas inlet of the environmental scanning electron microscope such that when in operation, a carrier gas circulates from the carrier gas supply through the gas humidifier and humidity sensor to the gas inlet of the environmental scanning electron microscope through the delivery valve.
Dependencies are inferred from the claim text.