HFIR Sample Environment
Neutron Sciences five-year strategic plan for sample environment. Comments are encouraged.
The Sample Environment Group provides equipment and support for studying materials under controlled conditions (temperature, pressure, magnetic field, chemical environment, etc.). When you come to SNS or HFIR to conduct an experiment, our “front line” teams will be there to support you. Although we currently offer a wide range of capabilities, we realize that these capabilities must continually grow. Therefore we also have a busy research & development team. We encourage you to partner with them to develop new equipment and techniques.
New User Partnership Program for Sample Environment Equipment Development
Neutron Sciences has initiated a new program to encourage the collaborative development of sample environment equipment. Several productive collaborations between users and the Sample Environment Group are already under way, and the new program will fund even more projects through a simple process:
- Interested users fill out a one-page template (Word, PDF).
- Sample Environment staff promptly contact the primary investigator to discuss the proposal.
- The Sample Environment Steering Committee (existing group of internal and external scientists) reviews and prioritizes proposals in May 2010.
Projects will be awarded and started as budget allows. Users and ORNL staff will be engaged in the actual development work. The scope is relatively small-scale (but high impact!) projects with a materials budget between $5000 and $20000 and some additional funds available to travel to ORNL and participate in equipment commissioning. Proposals may make use of existing equipment (e.g., designing a special insert for an existing cryostat). Interaction between users and ORNL staff (Sample Environment staff, instrument scientists, etc.) will be a key consideration for successful proposals, as well as a deliverable that will benefit the larger user program at SNS and HFIR. For more information, contact Lou Santodonato.
Developing New Sample Environment Capabilities at the HFIR
HFIR is in the midst of major upgrades in many areas, including sample environment. These upgrades are resulting from standard equipment purchases, addition of dedicated Sample Environment staff, and collaborative R&D.
Collaborative R&D
Fig. 2. Atmosphere furnace consisting of an off-the-shelf water-cooled outer jacket with ORNL-designed controls, zirconia foam liner, and MoSi2 heating elements.
ORNL scientists performed the first in-situ study of phase transformation under simultaneous high magnetic field and high temperature [1]. This proof of principle experiment began with building a high-temperature sample insert to fit inside the magnet on the WAND instrument of HFIR (fig. 1). The success of this new technique opens the door to greater understanding of the role of magnetic field on structure changes at high temperatures.
A 1700 Celsius controlled atmosphere reaction (CAR) furnace was tested off-line in October [2]. The CAR furnace will be commissioned on the HFIR WAND instrument, and will be available for use on other HFIR and SNS instruments. Additional furnace designs are under development.
Several high pressure projects are underway. The Sample Environment group is working with the SNAP (Spallation Neutrons And Pressure) team to develop a cryogenic cooling rig for large anvil pressure cells. Special gas pressure cell are also being developed for use at both the HFIR and the SNS.
Progress Reports
[1] G. M. Ludtka and J. Fernandez-Baca, Neutron Sciences Progress at Oak Ridge National Laboratory, July 2007
[2] Original design by A. Payzant, ORNL Laboratory Directed Research and Development Award; Adapted and assembled by Sample Environment Group
Fig 3. Controlled environment sample cell for in situ neutron scattering studies of clathrate hydrates. The image to the right shows methane hydrate forming in the upper half of the sapphire cell.
