SNS commissioning moves to next phase

This month the Spallation Neutron Source (SNS) began commissioning the next section of the linear accelerator (linac). The SNS linac consists of four different types of accelerators, the one being tested is the drift-tube linac (DTL). Testing consists of generating a pulsed current of negative hydrogen ions (H-) and accelerating them through three of six drift-tube tanks. After acceleration, the beam is channeled to a specific diagnostics location for measurement before being stopped.

The DTL is the second major SNS accelerator subsystem to be commissioned, a system that eventually delivers a high-energy proton beam to a mercury target. When the proton beam impacts the mercury target, neutrons are produced, or "spalled," and are directed to a variety of experiment stations where research is conducted.

The DTL subsystem was designed and built at Los Alamos National Laboratory (LANL) in New Mexico and is one of LANL's main contributions to the SNS project. The first components of the DTL were delivered to the SNS site in May 2002, and the last components for the sixth DTL are now being received. The tests being conducted are significant because they verify subsystem performance to design specifications. This successful testing of half of the DTL brings the beam energy up to 40 MeV; previous tests had reached 7.5 MeV. The completed linac will eventually reach 1000 MeV.

When completed in 2006, SNS will become the world's leading research facility for study of the structure and dynamics of materials using neutrons. It will operate as a user facility that will enable researchers from the United States and abroad to study the science of materials that forms the basis for new technologies in energy, telecommunications, manufacturing, transportation, information technology, biotechnology, and health.

SNS is under construction at the Department of Energy's Oak Ridge National Laboratory.