Press Release - NASA STTR Contract

Electron Energy Awarded NASA STTR Contract to Study SmCo High-Temperature Magnets for Space Power and Propulsion

LANDISVILLE, PA (April 2, 2004) — Electron Energy Corporation, a long-standing innovator in the field of rare-earth magnets, has been awarded a Small Business Technology Transfer Research (STTR) contract by NASA to study the effects of radiation and thermal stability of samarium cobalt (SmCo) high temperature permanent magnets for space power generation using Stirling linear alternators, and for ion propulsion thrusters. The contract will be managed by NASA’s Glenn Research Center (GRC), Cleveland, Ohio.

NASA GRC program management recently selected the EEC-led team to meet the requirements of the one-year $94,400 contract. EEC will be supported in these efforts by the University of Dayton Research Institute and the Ohio State University.

The research program will study the effects of both ultra-high temperature and radiation on physical and magnetic properties, and the improvement of thermal stability in a vacuum at temperatures up to 550°C. Based on the research findings, improvements to magnets will be made to enhance the performance of high-power ion propulsion engines. This effort will build on the R&D efforts which led to the award of a US patent in 2002 for EEC’s high temperature samarium cobalt magnets which can operate at temperatures up to 550ºC, exceeding the performance of any other commercially-available material in the world by approximately 250ºC.

Samarium cobalt magnets designed and manufactured by EEC have already been successfully used in NASA’s Deep Space 1 Ion Engine, which was launched in 1998. Commercial, land-based uses which are emerging for this new high temperature magnet material include applications with sensors, instrumentation, generators, and actuators, vacuum, medical and semiconductor processing equipment. These samarium cobalt high temperature magnets provide designers with a material that is a few times higher in energy density than other ultra-high temperature-magnet materials, such as Alnico. This allows designers to create smaller, less costly, more powerful assemblies and systems that can operate in a wider thermal range. Moreover, system components containing magnetic materials can be designed to perform physically closer to extreme environments which occur in proximity of fission reactors and radioisotope heat sources. Hence total system mass can be reduced.

"High-temperature magnets, properly coated, are suitable for long-term service at temperatures as high as 550°C, and can be used in a wide variety of space-based applications," said Michael H. Walmer, president of EEC.

According to Dr. Jinfang Liu, Director of Technology at EEC, the major challenge for magnets in ion propulsion engines is the degradation caused by Sm depletion at ultra-high temperature in high vacuum. Although coated magnets perform well in many high temperature applications, NASA’s preference is to avoid coatings for magnets in the ion engine.

"To ensure the performance of future spacecrafts powered by ion engines, it is necessary to investigate and improve the thermal stability of high temperature magnets," Liu said. "If high-energy radiation adversely affects the magnetic field produced by high temperature magnets, the performance of the ion engine could be jeopardized."

In ion engines, xenon (Xe) atoms are bombarded with electrons to cause ionization. Permanent magnets create an axial magnetic field designed to maximize the collisions of electrons and Xe atoms. The resultant ions are then accelerated through a grid, creating a thrust which accelerates the vehicle. Although the thrust is very low, typically equivalent to the weight of a piece of paper, it is constant and extremely efficient. A consistent magnetic field is critical to the performance of the ion engine in space with extreme environments consisting of high and low temperatures, high vacuum and gamma photon and particle radiation.

Peter C. Dent, EEC’s Director of Sales & Marketing said "There is little data about the effects of radiation on samarium cobalt permanent magnets and none on the new, patented high temperature SmCo magnets." It is known that SmCo magnets perform without degradation in radiation environments considered hostile enough to cause significant losses in magnetic properties to neodymium iron boron magnets. Although radiation resistance for SmCo is high, the threshold, or the point above which degradation will occur, is largely undetermined.

Dent said the technical objectives of the study include documenting the thermal stability of high temperature magnets in vacuum conditions at the operating temperatures of high-power ion engines; establishing a method of accelerated testing by formulizing the relationship of temperature and time for magnetic degradation; investigating the possibility of better thermal stability of high temperature magnets with nano-crystalline microstructure; documenting all possible effects of radiation on the magnetic properties of high temperature magnets for NASA’s database; and exploring the possibility of reducing those effects that work against magnetic performance.

The University of Dayton Research Institute (UDRI) and Ohio State University (OSU) will partner with EEC in the research study. EEC and UDRI have worked together for 30 years and have long been recognized for their accomplishments in the area of permanent magnet research and development, commercialization and production. This team has successfully pioneered much of the development of the rare-earth permanent magnet materials in use today in numerous military and commercial applications.

Since 1996, EEC has been granted eleven STTR or SBIR Phase I and Phase II programs, which resulted in one patent and two pending patents, as well as over 20 papers published in professional journals.

For more information about Electron Energy Corporation’s high temperature magnets, call toll-free at 1-800-824-2735. Our staff of engineering specialists is available for free technical consultations, and will travel to on-site meetings.