Cometary Noble Gas
A team of SwRI astronomers recently detected the noble gas argon in comet Hale-Bopp - the first sighting of a noble gas in a comet. Noble gases provide valuable tracers of thermal history and, therefore, clues to the origins of comets.
The astronomers collaborated with three colleagues from the University of Colorado, the University of Maryland, and the Observatoire de Midi-Pyrenees in France. NASA supported the study.
The data on comet Hale-Bopp were obtained in the form of ultraviolet spectra during a NASA high-altitude suborbital research rocket flight on the evening of March 29, 1997, just as comet Hale-Bopp made its closest approach to the sun. According to team leader and Principal Investigator Dr. Alan Stern, director of the SwRI Space Studies Department, "The argon signals are weak, but unmistakable. We had previously suspected their presence, but were able to recently confirm the result when we cross-compared two independent spectra obtained by our rocket instrument back in 1997."
Adds co-investigator Dr. David Slater, a senior research scientist at SwRI, "Hale-Bopp was among the brightest comets ever witnessed, and surely the brightest comet in modern times. The detection of argon would not have been possible except for Hale-Bopp's unusually high brightness."
Because noble gases do not interact chemically with other elements and because noble gases are easily lost from icy bodies like comets at very low temperatures through processes much like evaporation, their presence or absence provides a way of measuring the thermal history of comets. University of Maryland astronomer and team member Dr. Michael A'Hearn explains, "That's the reason cometary astronomers have wanted to detect noble gases for so long. The advance of technology combined with the brightness of Hale-Bopp made this goal a reality."
Interestingly, the team's spectra showed that the argon abundance in Hale-Bopp was so high that it indicates the comet has always been quite cold and likely formed in the deep outer reaches of the solar system, far beyond its once- suspected birthplace in the somewhat warmer Jupiter zone. "Our results indicate that Hale-Bopp was likely formed in the Uranus-Neptune zone," says Stern. The high argon abundance of Hale-Bopp may also help explain the unexpected findings by the Galileo Jupiter entry probe, which found that Jupiter has an argon abundance similar to comet Hale-Bopp. "Perhaps Jupiter was seeded with extra argon by the impact of many comets like Hale-Bopp early in the history of the solar system," remarks Stern.
The detection of argon in Hale-Bopp has whet the scientists' appetite for more noble gas data on comets. The team is preparing an instrument called the ALICE Ultraviolet Spectrometer for NASA to fly to comet Wirtanen aboard the European-U.S. Rosetta comet orbiter mission to be launched in 2003. The team has proposed a series of additional NASA rocket launches in 2002 and 2003 to search for argon and other noble gases, even before the Wirtanen orbiter mission is launched. Stern says, "Using this even more sensitive generation of instruments, we look forward to comparing different comets to one another to learn about the diversity of cometary birthplaces."
Growth of the electric power industry and deregulation are changing the nature of power generation. Reciprocating engine technology is expected to be key to the future of the distributed power generation marketplace.
A cooperative research program focused on advanced reciprocating engine systems (ARES) is under way at SwRI to improve the stationary natural gas engines used for power generation. The consortium seeks to improve engine efficiency and reduce oxides of nitrogen emissions to 0.1 grams per brake horsepower-hour for stationary engines in the one- to two-megawatt power range. Current research is directed toward reducing combustion barriers such as knock and misfire, improving exhaust aftertreatment, and increasing power density.
Current ARES members include the Department of Energy, GRI, Caterpillar, Cooper Energy Services, Cummins Engine Company, Waukesha Engine Division, Southern California Gas, Altronic, Federal Mogul, and Woodward Governor.
Contact Tim Callahan at (210) 522-6890 or firstname.lastname@example.org.
SwRI has added capabilities in plasma immersion ion processing (PIIP) and plasma immersion ion implantation (PIII) to its Ion Surface Modification Facility. The new capabilities allow for surface modification of large, three-dimensional objects at or near room temperature.
"With the addition of PIIP and PIII to our existing capabilities, we can now address larger components (greater than one square meter) and heavier components (more than 500 pounds) than previously possible," says Dr. Kevin Walter, a senior research scientist in the SwRI Mechanical and Materials Engineering Division.
PIIP, developed at Los Alamos National Laboratory, is a relatively new vacuum technology for the application of hard, wear-resistant coatings. Like conventional physical vapor deposition methods, PIIP is used to deposit various coatings, but the non-line-of-sight PIIP approach allows simultaneous treatment of large components and complex shapes without requiring component manipulation.
The versatility of PIIP for surface modification allows the use of any gas with the same equipment. For example, a single vacuum chamber can use argon gas for sputter-cleaning or nitrogen gas for ion implantation. The same equipment can be used to deposit coatings from hydrocarbon gases or organometallic compounds. The process can also be used to deposit diamond-like carbon (DLC) coatings for roughly the same cost as electro-deposited hard chrome.
Potential applications include coating deposition to decrease friction and to improve wear and corrosion resistance. For example, DLC coatings can increase the scuffing resistance of aluminum pistons. Diamond-like carbon also has potential application as a wear-resistant coating for gears, bearings, and seals. Chromium oxycarbide coatings have been shown to be resistant to attack by molten aluminum, thus have potential applications in the aluminum die casting industry.
PIII is used primarily for nitrogen implantation to improve the wear resistance of metals and for other implantation processes for the semiconductor industry. The patented process was developed by the University of Wisconsin.
The most common use of PIII is for the nitrogen implantation of electro-deposited hard chrome. The process has been shown to increase wear life of hard chrome by a factor of two to three and to reduce the friction coefficient by approximately 30 percent.
"These are cutting edge technologies that are not yet commercially available, so SwRI is in a unique position to offer these services to U.S. industry," Walter adds.
The SwRI Ion Surface Modification Facility is the largest and most versatile commercial facility of its kind in North America. In addition to the vacuum chamber used for PIIP and PIII, the facility houses a 120-kilovolt plasma bucket ion source for nitrogen ion implantation of large surface areas and two vacuum chambers for ion beam-assisted deposition of coatings.
Contact Walter at (210) 522-5204 or email@example.com.
New ISO Certification
The SwRI Signal Exploitation and Geolocation Division has been certified as meeting ISO 9001 standards. The certification, issued by Lloyd's Register Quality Assurance of Hoboken, New Jersey, covers design, development, production, installation, and servicing activities.
"Current projects from Canada and Australia specify certification to ISO 9001 as the quality system, and requests for proposals from European countries are specifying ISO 9001 as the required quality system," says Tim Millington, director of the Production Systems and Software Engineering Department and the lead coordinator of the ISO initiative.
"With this certification, the Signal Exploitation and Geolocation Division is prepared to meet these requirements, as well as to continuously improve our operations to deliver the quality designs, products, and services our clients expect," he says.
SwRI provides advanced communications signal acquisition and recognition, direction finding, and geolocation systems to government, military, and commercial clients in the U.S. and around the world.
Other ISO-certified groups at SwRI include the Automotive Products and Emissions Research Division, the Engine and Vehicle Research Division, and the Bioengineering Department. Others are preparing for certification.
ISO 9001, initiated in the late 1980s by the International Organization for Standardization, is used to certify a quality system for the development of products, starting with initial design through production and servicing.
Contact Dennis Berry at (210) 522-2804 or firstname.lastname@example.org.
Burch to Chair Committees
Dr. James L. Burch, vice president of the SwRI Instrumentation and Space Research Division, has been selected to chair committees for the National Research Council (NRC) and the American Geophysical Union (AGU).
The NRC Space Studies Board oversees the Committee on Solar and Space Physics, to be chaired by Burch for a three-year term beginning in July. The committee advises the Board in the areas of solar physics, solar-terrestrial physics, magnetospheric physics, cosmic radiation, sun-Earth connections, and space weather. In this capacity, the committee develops research strategies and monitors their implementation for NASA, the National Oceanic and Atmospheric Administration, the National Science Foundation, and other government agencies.
Also in July, Burch will begin a two-year term as chairman of the AGU Committee on Public Affairs. This committee ensures that the geophysical science community participates in public policy decisions. It is also involved in selecting an annual congressional Fellow, advising government officials, developing positions on issues, advocating AGU positions, and encouraging awareness and involvement of AGU members in policy issues that affect science in general and the Earth and space sciences in particular.
In addition to directing a variety of space science activities at the Institute, Burch has served as principal investigator or co-investigator on more than 10 space science missions, including Cassini, Rosetta, the Upper Atmosphere Research Satellite, and Dynamics Explorer 1. Burch is currently serving as principal investigator of the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) mission, which launched in March 2000.
Contact Burch at (210) 522-2526 or email@example.com.
Levison Appointed Vice Chair
Dr. Harold F. Levison, a principal scientist in the SwRI Department of Space Studies, has been elected vice chairman of the Division on Dynamical Astronomy of the American Astronomical Society. He will serve as chairman in 2001.
The Division focuses on all aspects of dynamical astronomy, including celestial mechanics, solar system dynamics, planet formation, stellar dynamics, dynamics of the interstellar medium, galactic dynamics, and cosmology.
Levison's work on the solar system has included studies of the long-term dynamical behavior of comets and the origins of planets. In 1997, he co-predicted the existence of the scattered disk of objects called the Kuiper Belt, and has since studied the dynamics of those objects. He also performed numerical integrations of the orbits of thousands of Kuiper Belt objects over a simulated four billion years - the age of the solar system.
Levison's principal research interest is the dynamics of astronomical objects, in particular, the long-term behavior of solar system bodies. Although he has undertaken both observational and theoretical projects in the pursuit of these interests, most of his research involves the development of large-scale numerical experiments.
Contact Levison at (303) 546-0290 or firstname.lastname@example.org.
SwRI has been selected a prime contractor in a Design and Engineering Support Program (DESP) providing up to $450 million in services, primarily for the U.S. Air Force Materiel Command (AFMC).
"This contract continues a history of SwRI's work for the AFMC," says Dr. O. Hal Burnside, a director in the Mechanical and Materials Engineering Division. The Institute is providing services to Air Logistic Centers at Ogden, Utah; Warner Robins, Georgia; Sacramento, California; Oklahoma City, Oklahoma; San Antonio; and to Wright-Patterson Air Force Base, Ohio.
The DESP was created to meet future diversified engineering needs by providing engineering and high-level technical services in support of all AFMC weapons systems, components, and support equipment. It will focus on incorporating proven technologies and methods into Air Force systems and processes.
One of 13 DESP prime contractors, SwRI has teamed with subcontractors Analysis & Technology, Inc. of Middletown, Rhode Island, and ML Technologies, Inc. of Layton, Utah. SwRI will provide services during the next five years to the AFMC and other federal agencies.
Published in the Summer 2000 issue of Technology Today®, published by Southwest Research Institute. For more information, contact Maria Stothoff.