Allen R. Sampson

Advanced Research Systems

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G. A. Jerman

Marshall Space Flight Center

Jessica A. Gaskin

Marshall Space Flight Center

Don A. Gregory

University of Alabama in Huntsville

Terry Abbott

University of Alabama in Huntsville

Stephanie Medley

University of Alabama in Huntsville

K. G. Thaisen

University of Wisconsin–River Falls

Brian D. Ramsey

Marshall Space Flight Center

R. P. Harvey

Case Western Reserve University

L. A. Taylor

University of Tennessee at Knoxville

Lisa Taylor

University of South Wales

Cooperative Institutions

University of Alabama in Huntsville

Intel (United States)

University of Alabama

Marshall Space Flight Center

Johns Hopkins University Applied Physics Laboratory

Johns Hopkins University

University of Tennessee at Knoxville

National Space Science and Technology Center

Planetary Science Institute

University of Cambridge

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Research Field

Optimization of a Cold Field Emission Electron Gun for a Miniaturized Scanning Electron Microscope

Lunar and Planetary Science Conference (2010)

Stephanie Medley Don A. Gregory Allen R. Sampson Jessica A. Gaskin

Field emission gun

Electron gun

Field emission microscopy

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Citations (1)

Miniaturized Scanning Electron Microscope for In Situ Planetary Studies

Earth and Space 2021 (2010)

Jessica A. Gaskin Terry Abbott Stephanie Medley Kira D. Patty Don A. Gregory

The exploration of remote planetary surfaces calls for the advancement of low-power, low-mass, highly-miniaturized instrumentation. Multi-functional instruments of this nature will prove to be particularly useful in preparation for human return to the moon, and in exploring increasingly remote locations in the Solar System. To this end, our group has been developing a miniaturized Scanning Electron Microscope (mSEM) capable of remote investigations of mineralogical samples through in-situ topographical and chemical analysis on a fine scale. Specifically, the fabrication and testing of a proof-of-concept assembly has begun, and consists of a cold-field-emission electron gun and custom high-voltage power supply, electrostatic electron-beam focusing column, and scanning-imaging electronics plus backscatter electron detector. The functioning of an SEM is well known: an electron beam is focused down to nanometer- scale onto a given sample resulting in emissions such as backscattered and secondary electrons, x rays, and visible light. Raster-scanning the primary electron beam across the sample results in a fine-scale image of the surface topography (texture), crystalline structure and orientation, with accompanying elemental composition. The flexibility in the types of measurements the mSEM is capable of makes it ideally suited for a variety of applications. The mSEM is appropriate for use on multiple planetary surfaces, and for a variety of mission goals (from science to non-destructive analysis to in-situ resource utilization). The current status of the development and potential mSEM applications for planetary exploration are summarized here. This effort is funded through the NASA Research Opportunities in Space and Earth Sciences - Planetary Instrument Definition and Development Program (PIDDP).

Field emission gun

Secondary electrons

Acceleration voltage

Instrumentation

10.1061/41096(366)113

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Citations (9)

Miniaturized Environmental Scanning Electron Microscope for In Situ Planetary Studies

Jessica A. Gaskin Terry Abbott Stephanie Medley Don A. Gregory K. G. Thaisen

The exploration of remote planetary surfaces calls for the advancement of low power, highly-miniaturized instrumentation. Instruments of this nature that are capable of multiple types of analyses will prove to be particularly useful as we prepare for human return to the moon, and as we continue to explore increasingly remote locations in our Solar System. To this end, our group has been developing a miniaturized Environmental-Scanning Electron Microscope (mESEM) capable of remote investigations of mineralogical samples through in-situ topographical and chemical analysis on a fine scale. The functioning of an SEM is well known: an electron beam is focused to nanometer-scale onto a given sample where resulting emissions such as backscattered and secondary electrons, X-rays, and visible light are registered. Raster scanning the primary electron beam across the sample then gives a fine-scale image of the surface topography (texture), crystalline structure and orientation, with accompanying elemental composition. The flexibility in the types of measurements the mESEM is capable of, makes it ideally suited for a variety of applications. The mESEM is appropriate for use on multiple planetary surfaces, and for a variety of mission goals (from science to non-destructive analysis to ISRU). We will identify potential applications and range of potential uses related to planetary exploration. Over the past few of years we have initiated fabrication and testing of a proof-of-concept assembly, consisting of a cold-field-emission electron gun and custom high-voltage power supply, electrostatic electron-beam focusing column, and scanning-imaging electronics plus backscatter detector. Current project status will be discussed. This effort is funded through the NASA Research Opportunities in Space and Earth Sciences - Planetary Instrument Definition and Development Program.

Field emission gun

Instrumentation

Characterization

Secondary electrons

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Simulation and characterization of a miniaturized Scanning Electron Microscope

Jessica A. Gaskin G. A. Jerman Stephanie Medley Don A. Gregory Terry Abbott

A miniaturized Scanning Electron Microscope (mini-SEM) for in-situ lunar investigations is being developed at NASA Marshall Space Flight Center with colleagues from the University of Alabama in Huntsville (UAH), Advanced Research Systems (ARS), and the University of Tennessee in Knoxville (UTK). Scanning Electron Microscopes (SEMs) can provide information on the size, shape, morphology and chemical composition of lunar regolith. Understanding these basic properties will allow us to better estimate the challenges associated with In-Situ Resource Utilization and to improve our basic science knowledge of the lunar surface (either precluding the need for sample return or allowing differentiation of unique samples to be returned to Earth.) Miniaturization (and power reduction) of an SEM appropriate for in-situ planetary investigations has warranted several novel re-designs of traditional SEM components. As such, this research has been centered on these principle elements and includes: an electron gun, beam defining and focusing system, and deflection/scanning/imaging system. Of these, the electron gun development, which is the focus of this paper, is of particular importance as it dictates the design and operation of the remaining components.

Characterization

Regolith

Scientific instrument

10.1109/aero.2011.5747297

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Citations (6)

Simulation and Characterization of a Miniaturized S canning Electron Microscope

A. Gaskin G. A. Jerman Stephanie Medley Don A. Gregory Terry Abbott

Characterization

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Development of a Miniature Scanning Electron Microscope to Facilitate In Situ Lunar Science and Engineering

Earth and Space 2021 (2010)

K. G. Thaisen Jessica A. Gaskin Brian D. Ramsey G. A. Jerman Allen R. Sampson

Returning humans to the Moon for prolonged periods will require extensive information on the properties and compositions of the lunar regolith, its resource potential, and in-situ characterization of the effects of space weathering of the soil and equipment. To address these concerns, we are developing a miniature Scanning Electron Microscope (mSEM), a project led by the NASA Marshall Space Flight Center (MSFC), for use on the lunar surface. Working within the lunar environment and at low-power provides opportunities to simplify the instrument, as well as sample preparation. The natural lack of an atmosphere eliminates the need and complexity of a vacuum chamber on the instrument and introduces the possibility of a "point-and-shoot" configuration for the mSEM. Imaging with low-power does not require sample coatings of carbon or gold, or the use of a gas, to mitigate surface charging on the sample; this low-power greatly simplifies sample preparation. Engineering and science activities on the lunar surface will benefit from the presence of an mSEM and its ability to determine particle size distribution (PSD), mineral chemistry, and the general characteristics of the regolith.

Regolith

Scientific instrument

Sample (material)

Characterization

Lunar soil

10.1061/41096(366)97

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Citations (6)

Sensor networks in Intel fabrication plants

Jasmeet Chhabra Nandakishore Kushalnagar Benjamin Metzler Allen R. Sampson

The deployment of large-scale sensor networks in industrial environments presents technical challenges in achieving ease of deployment, flexibility in operation, and overall commercial viability. Sensor deployments are characterized by non-uniform placement of nodes, intermittent node connectivity, and the aggregation and reliable transfer of a large amount of data as networks scale to larger and larger sizes. Operation challenges include efficiently utilizing battery powered nodes, dynamically selecting sample periods and equipment clusters of interest, integrating with existing sensing and analysis infrastructure and easily correlating faults identified by the sensor network back to key factory operations and equipment. Commercial aspects involve returning value to the organization with hardened network nodes and reliable network operation that easily justifies the sensor network deployment and operating costs. We will demonstrate a sensor network in the ultra-pure water facility of an Intel fabrication plant, including details on the fab vibration application, the hardware nodes, and the heterogeneous wireless network.

Factory (object-oriented programming)

Sensor web

Sensor node

10.1145/1031495.1031567

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Citations (8)

Standards-based public wireless LAN access and roaming

R. Narjala A. Keddy J. Rover Allen R. Sampson

Deployment of public wireless local area network hotspots is growing rapidly around the globe. While the outlook for these networks appears promising, there are several issues that need to be resolved before they can become viable as effective global solutions for wireless data connectivity. This paper describes some of the steps that are being taken within the industry to standardize wireless network authentication, billing, and roaming.

Roaming

Wireless WAN

Municipal wireless network

Fixed wireless

Wireless LAN controller

Wireless site survey

Wireless distribution system

10.1109/icbn.2005.1589791

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Miniature Variable Pressure Scanning Electron Microscope for in-situ imaging & chemical analysis

IEEE Aerospace Conference (2012)

Jessica A. Gaskin G. A. Jerman Jane Gregory Allen R. Sampson

NASA Marshall Space Flight Center (MSFC) is leading an effort to develop a Miniaturized Variable Pressure Scanning Electron Microscope (MVP-SEM) for in-situ imaging and chemical analysis of uncoated samples. This instrument development will be geared towards operation on Mars and builds on a previous MSFC design of a mini-SEM for the moon (funded through the NASA Planetary Instrument Definition and Development Program). Because Mars has a dramatically different environment than the moon, modifications to the MSFC lunar mini-SEM are necessary. Mainly, the higher atmospheric pressure calls for the use of an electron gun that can operate at High Vacuum, rather than Ultra-High Vacuum. The presence of a CO ₂ -rich atmosphere also allows for the incorporation of a variable pressure system that enables the in-situ analysis of nonconductive geological specimens. Preliminary testing of Mars meteorites in a commercial Environmental SEM™ (FEI) confirms the usefulness of low-current/low-accelerating voltage imaging and highlights the advantages of using the Mars atmosphere for environmental imaging. The unique capabilities of the MVP-SEM make it an ideal tool for pursuing key scientific goals of NASA's Flagship Mission Max-C; to perform in-situ science and collect and cache samples in preparation for sample return from Mars.

10.1109/aero.2012.6187064

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Miniature Scanning Electron Microscope for In-Situ Planetary Studies: Electron Gun Development

Lunar and Planetary Science Conference (2009)

Jessica Gaskin G. A. Jerman Brian D. Ramsey Cynthia K. Ferguson Terry Abbott

Summary: Good progress is being made on the de-sign and fabrication of a miniature SEM, keeping in mind the scientific and engineering needs of sample characterization with the planned return of landers and humans to the Moon. Testing of the electron gun will take place in a custom vacuum chamber at MSFC spe-cifically designed for this. Results from these tests will be presented as well as a plan for integration of the electron gun onto an electron focusing column (previ-ously developed at MSFC using internal funding) and design plan for further miniaturization of the system. Additional design considerations will be made throughout the project to accommodate other planetary surfaces (such as Mars), where operating in environ-mental mode offers added benefits. References: [1] Chambers, J. G., et al. (1994) En-gineering, Construction, Operations in Space IV , vol. II, 878-888. [2] Chambers, J. G., et al. (1995) JGR-Planets, 100 , E7, 14, 391-14,401. [3] Heiken, G. T., Vaniman, D. T. and French, B. M. (1991)

Electron gun

Scientific instrument

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Citations (5)