NSTec, Los Alamos Honored with Distinguished Performance Award

October 29, 2008

A science team of physicists and engineers from National Security Technologies Los Alamos Operations (NSTec-LAO) and Lawrence Livermore National Laboratory (LLNL) has received a distinguish performance award.

Robert Hilko and Douglas Johnson of NSTec–LAO, along with Anemarie DeYoung, Thomas Gorman, Chad Olinger, and Roddy Walton of LANL, were recently honored with a Small Team Distinguished Performance Award for their reanalysis work of the COALORA pinhole neutron experiment (PINEX). This interest went beyond Los Alamos to include members from Lawrence Livermore National Laboratory, such as the former LANL physicist Paul Weiss, who originally fielded the COALORA PINEX.

The Underground Nuclear Testing program at the Nevada Test Site (NTS) historically generated a suite of data sets that now serves as a national resource since the advent of the cessation of testing. These data are required for validation of weapons design codes necessary for Stockpile Stewardship.

Perhaps the single most important data set involves a movie of the primary in action, known as a PINEX experiment. PINEX—producing an image of the neutrons in a device—was not fully appreciated in its time. However, a few experimentalists were quick to see the exceptional value and power of PINEX in diagnosing device processes, says Tom Tunnell, manager of the LAO Physics and Analysis section.

“The Nevada Test Site Underground Nuclear Testing program originally produced only two successful time-resolved PINEX. The Nuclear Device Data and Science team, comprised of scientists from NSTec and LANL’s P-23 and X-2 groups, exhibited exceptional creativity and dedication in their reanalysis of one of these: COALORA,” Tunnell says.

The COALORA PINEX has now been successfully reanalyzed and a “movie” created showing the device in action. Those who assisted with the project include:

• Douglas Johnson is an electrical engineer at NSTec who worked on PINEX diagnostics for EG&G during the days of testing. His work now specializes in PINEX image processing and archiving. Douglas produced the original COALORA TRP movie, created from the nine time-sequenced images resulting from the COALORA time-resolved PINEX, which has been used for 20 years. This year, he interpolated between the team’s reanalyzed images to create the continuous reanalyzed movie.
• Robert Hilko is a physicist at NSTec who worked on neutron diagnostics for EG&G during the days of testing. Robert has been the resident expert on neutron experiment (NUEX) data from the NTS testing days but now his work focuses on PINEX image processing. Robert’s unparalleled dedication to this effort, along with that of Roddy Walton, is being touted as the main reason for the success of this team.
• Anemarie DeYoung is a Deputy Group Leader in the Neutron Science and Technology (P-23) Group at LANL, physicist, and P-23 Principal Investigator on Boost. She led this team’s effort to reanalyze the COALORA time-resolved PINEX.
• Thomas Gorman is a physicist and primary designer in the Applied Physics (X-2) Group at LANL. He provided movie calculations of COALORA using different weapons physics models for comparison with data.
• Chad Olinger is a physicist and the team leader for the Nuclear Device Data and Analysis Team. He enabled the COALORA reanalysis and assisted on PINEX analysis work.
• Roddy Walton is a physicist and LANL’s expert on PINEX, having fielded many such diagnostics during the days of testing. He is a retiree that contracts with LANL and mentors NDDS Team Members.

LANL’s Distinguished Performance Award recognizes employees or groups of employees “who have distinguished themselves by their outstanding contributions and performance in support of [LANL’s] programmatic efforts.” This movie was shown recently by the Applied Physics (X) Division to the United States Strategic Command’s (USSTRATCOM) Strategic Advisory Group Stockpile Assessment Team (SAGSAT) committee. The real-time data imaging of a dynamical pit is critical for validating Advanced Simulation and Computing models in support of Stockpile Stewardship.

“It took unusual creativity by the dedicated team to search and find papers in the archive on every aspect of the time-resolved PINEX camera calibration and timing electronics,” Tunnell says. “Although more than 30 percent of the background documentation was not found, the team innovatively used other diagnostics, such as NUEX, to calibrate and cross-check the PINEX results.”

NUEX measured the neutron flux up the line-of-sight as a function of time. A chi-squared minimization between PINEX and NUEX data was used to optimize frame-by-frame PINEX image times and intensities. “The result was timing good to within one nanosecond, and relative intensities of the images good to within the uncertainty of the NUEX data of a few percent. Despite an incomplete calibration data set, and despite the complexity of the task, the small team worked diligently to produce this movie,” Tunnell says.