UD plays role in development of neutron science facility

The University is playing a major role in a consortium that has submitted a $340 million proposal to the National Science Foundation (NSF) to add a long wavelength target station (LWTS) to the Spallation Neutron Source complex, a new neutron science facility under construction at the U.S. Department of Energy's Oak Ridge National Laboratory (ORNL) in Tennessee.

Henry Glyde, physics and astronomy, a collaborator on the proposal submitted by the University of Tennessee, said, "Since the LWTS will be predominantly used by university researchers and because UD has been very much part of getting it off the ground, if it is funded, we could be involved in its scientific management."

ORNL broke ground for the Spallation Neutron Source (SNS) in December 1999. The 75 acre, $1.4 billion facility, expected to be completed by 2006, will be the "world's most powerful neutron scattering source." According to ORNL, it is the newest facility in the Oak Ridge research complex and will be used to better understand the structure and dynamics of physical and biological materials.

SNS is an accelerator-based neutron scattering (spallation) instrument that will produce the most intense pulsed-neutron beams in the world. The more intense the beam, the more precisely it can delve into the makeup of physical and biological materials from polymers to proteins.

Neutron scattering is used by a variety of sciences to study the arrangement, motion and interaction of atoms. The device has been used in osteoporosis research and in the development of plastics for things like shatterproof windows.

Neutron scattering is a very efficient way of examining molecules because the scattering pattern tells scientists about the dynamics and structure of atoms within materials without disturbing their makeup, Glyde said.

The SNS begins the process with an ion chamber that produces negatively charged hydrogen ions or protons orbited by two electrons.

The ions are shot through a linear accelerator into a chamber that strips off the electrons leaving just the protons. The protons pass through an accumulation accelerator where they gather into bunches and are released as pulses that strike a liquid mercury target, scattering neutrons and producing the pulsed-neutron beams that will be 50 to 100 times more intense than any now obtainable from another source.

UD is a member of the Southern Universities Research Association that is in the process of building the $400 million accumulation accelerator.

The facility at Oak Ridge is being built with a high power target station that will send both hot and cold neutrons to diagnostic instruments. What UD and the other 11 universities are proposing is another target station, the LWTS, dedicated to cold neutron diagnostics and research.

Long wavelength neutrons can delve deeper into a material than can thermal pulses and has wider application in government and industry.

Development of the LWTS proposal was initiated at a workshop held at UD in April 1999. Glyde, with input from Eric Kaler, Elizabeth Inez Kelley Professor of Chemical Engineering, and help from Leda Shoun and Helen Long, both physics and astronomy, organized the workshop which led to a $4.5 million grant from NSF to develop a full proposal.

That grant funded additional workshops at UD and other consortium universities that resulted in the $340 million LWTS proposal submitted to NSF on Feb. 2. Glyde said he is confident funding will be approved but expects the process to take up to two years.

–Barbara Garrision