Eric Dutra’s Zoo: The Benefits of Using the Zebra Z-pinch Device and the Leopard Laser

Ten miles outside of the University of Nevada, Reno’s (UNR’s) campus, principal investigator Eric Dutra works in a lab on his Site-Directed Research and Development (SDRD) project “Staged z-pinch and variable-energy laser ablation-driven new high-yield neutron source”. This lab, which is owned by the university, is home to a leopard and a zebra. But it isn’t a zoo like you would expect; the animals are actually the names of technologies belonging to UNR. They are the Leopard laser and the Zebra Pulsed-Power Generator, respectively.

So, why does Eric use this zoo of devices? The NNSS requires neutron sources to assess its aging nuclear stockpile, and although the current sources suffice, future experiments will require a higher yield and brightness. Eric hopes to create a new platform that will anticipate, and one day meet, the NNSS’ future stockpile needs.

To do this, Eric is using the LAZE apparatus, which combines the capabilities of the Leopard laser and the Zebra Pulsed-Power Generator: the Leopard laser produces an ablation plume target that is then pinched by Zebra. The resulting neutron yield is proportional to that of the Dense Plasma Focus (DPF) currently being used by the Z-pinch Experimental Underground System (ZEUS), but its creation time is ~10 ns, which is much faster than ZEUS’ creation time of ~60–100 ns. Eric believes that with proper load and material processing, optimization of the plasma plume, and optimization of the current through a z-pinch plasma column, the yield can be increased to eventually surpass the DPF.

Although the main goal of this project is to support stockpile stewardship, Eric has also been considering how it can help the NNSS enter the neutron survivability space. Currently, Eric is producing neutron yields on the order of 1011, but an increased yield of approximately 1013 would allow the NNSS to offer solutions to problems in the survivability world.

To work toward that distinction, Eric and his team collaborate closely with the faculty and students at UNR. Professors from the university provide support to Eric’s team by helping with general physics and running the lab. Eric is also involved with hiring both graduate and undergraduate interns to work on the project. Because there are so many processes involved with creating a high-yield neutron source, these interns often use their work on the project for research experience, dissertations, or theses. To date, there have been six seniors who have written theses about or received funding from this project.

Eric’s own journey at the NNSS started when he was an intern in 2010 and 2011. After working on Rob Buckles’ SDRD project, he decided to stay with the company. He hopes his project will give interns good experience in the workplace and will inspire them to pursue a career with the NNSS. Some of Eric’s interns have already been making this hope a reality: former UNR undergraduate Zack Wolff, who worked with Eric on another project, was hired on at Livermore Operations after he graduated.

Despite some setbacks from repairs to the Leopard laser and the Zebra Pulsed-Power Generator, Eric still plans to move forward with his research. His goal for the next fiscal year is to better understand the dynamics of the experiment through machine diagnostics and multi-head detector and PIC modeling. Data from the diagnostics will help the team to better grasp how the plume dynamic affects the z-pinch column, which can be used to optimize the pitch and neutron yields. Diagnostics will also help them to understand the experiment’s current, energy, ablation, and lode, which are all needed to create a simulation that will optimize the parameters. By better comprehending the dynamics of the experiment, Eric hopes to streamline and downsize the process of neutron yield so that it can be more effective underground.

As Eric and his team continue to work toward their goal of improving neutron yield, we wish them the best!