Status of the darht 2nd axis accelerator at the Los Alamos national laboratory

Abstract

The Dual Axis Radiographic Hydrodynamic Test Facility (DARHT) was constructed at Los Alamos National Laboratory as a radiographic facility to provide dual-axis multi-time radiography to support the US Stockpile Stewardship Program. The DARHT 1 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">st</sup> Axis has been operational since 1999 and has been providing excellent radiographs. The DARHT 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">nd</sup> Axis construction project was completed in early 2003. However, during the subsequent commissioning efforts to bring it to the full specifications of 17 MeV, 2 kA and 2 microsecond pulse length, high voltage breakdown was observed in several of the 78 induction accelerator cells. In January 2004, the DARHT 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">nd</sup> Axis Refurbishment and Commissioning Project was launched. It is a Los Alamos National Laboratory effort in collaboration with the Lawrence Livermore and Lawrence Berkeley National Laboratories. Its purpose is to first address the HV breakdown problems with the 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">nd</sup> Axis accelerator cells, address the remaining physics of the multi-pulse electromagnetic kicker and X-ray converter target and then commission the full energy 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">nd</sup> Axis accelerator. The redesign of the cell as well as long pulse beam stability tests were completed in 2005. Testing of the multi-pulse electromagnetic kicker and X-ray converter target was completed in February of this year using an 8 MeV scaled accelerator that used twenty-six refurbished accelerator cells. Commissioning of the 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">nd</sup> Axis 2.5 MV, 2.0 kA electron injector and the full-energy accelerator beamline is currently underway. Commissioning of the downstream transport section and multi-pulse kicker will begin in early October of 2007 after accelerator commissioning is completed. Target commissioning is scheduled to begin in November 2007. The DARHT 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">nd</sup> Axis is scheduled for completion in early 2008, at which point the DARHT facility will be ready to support two-axis, multi-pulse radiography in support of the Stockpile Stewardship Program. In this paper, we present the overall project status, commissioning strategy and schedule.