US’ new nuke testing accelerator is 2.44 million pound, 400-foot long

Work that began on March 7 aims to build two accelerator modules for the Scorpius system, consisting of a 400-foot-long-linear accelerator being built at the Nevada National Security Site. Though a lengthy and complicated process, the LANL has previously built similar accelerator cells for the Dual-Axis Radiographic Hydrodynamic Test (DARHT). The facility was designed to take high-speed photos of mock nuclear devices that use plutonium surrogates.

These mock devices imploded at speeds greater than 10,000 miles an hour. The high-speed images gave DARHT scientists valuable data. However, scientists are keen to conduct experiments with actual plutonium, which is expected to provide more avenues for expanding our knowledge about the material.

Assembling the gigantic structure

Each accelerator module assembled at LANL is about five feet wide, 10 feet long, and 10 feet tall. Each module consists of three cells, each roughly three feet in diameter.

“Each of these cell modules is a physical vacuum chamber with magnets, power connection, vacuum pumps, cooling water, and controls that must be precision aligned to the next one in line within microns,” said Mike Furlanetto, ASD senior director in a press release. “Getting everything together at that level of accuracy and precision does take some time.”

The assembly of the two modules is expected to be completed later in 2024. They will be shipped to Nevada by road and connected to other components of the Scorpius ASD. Once the on-ground testing is completed, a vendor will build another 96 cells to complete the accelerator.

Finally, all the cells and remaining parts of the Scorpius facility will be transported 1,000 feet underground by elevator for the final assembly of the Scorpius ASD. The instrument will weigh 2.44 million pounds and be longer than a football field.

What will Scorpius do?

Scorpius is part of the larger Principal Underground Laboratory for Subcritical Experiments (PULSE) complex, which LANL, Sandia, Lawrence Livermore national laboratories, and the Nevada National Security Site operate.

When ready, the solid-state pulsed-power system built by Livermore will provide power by injecting an energized electron beam. The electron beam injector, built by Sandia, will break this beam down into four or more pulses separated by about 200 nanoseconds into the accelerator.

The 102 cells in the accelerator are designed to increase the energy of the pulses to over 20 megaelectron volts. Each of these pulses will then collide with a metal target near the end of the machine and generate X-rays that will pass through a stainless steel vessel containing plutonium.

A detector will convert the X-rays into images captured by a high-speed camera that scientists can study to gain additional insights. “

We’re extremely confident in the reliability of the nation’s current nuclear stockpile,” added Furlanetto in the press release, “but with Scorpius, we will have the ability to explore everything from new materials, new designs, new delivery systems.”