Lawrence Livermore National Laboratory



Second Dual-Purpose Positioner Goes to Work

The first active target diagnostic was successfully fielded on NIF’s second target and diagnostic manipulator, known as TanDM 124, on Jan. 10, marking an important new capability for continued enhancement of NIF’s productivity.

Technicians Participate in TanDM CommissioningNIF technicians Max Bergonia (left) and Im Forth maneuver a TanDM 124 diagnostic load package during the dual-purpose positioner’s commissioning. Credit: Arlen Rowe

While the first TanDM, installed in 2016, has largely been dedicated to inserting targets in the NIF Target Chamber (see “NIF’s Dual Purpose Positioner Is Proving Its Worth”), TanDM 124 will primarily be used for diagnostics. The TanDMs were designed to provide better access for diagnostic exchanges than the existing diagnostic instrument manipulators, or DIMs. TanDM 124 will enable diagnostic exchanges in less than one hour and “snout” exchanges in less than 20 minutes.

TanDM 124 was installed in the NIF Target Bay last March, and the commissioning team then set to work connecting it to the facility’s infrastructure—the vacuum pumps, roughing pumps, electrical system, ventilation system, alignment systems, and computer control system. Commissioning of the positioner was completed last fall, followed by the start of operational qualification of the dozens of diagnostics used on NIF.

“The harder stuff to do was all the cable infrastructure,” said LLNL engineer Jonathan Fry, who led the TanDM 124 integrated commissioning team. “The diagnostics generally need a huge suite of cabling for the gated x-ray detectors, the hardened x-ray detectors, and the DISCs (DIM-insertable streak cameras).

“Whatever (diagnostic) you can shoot on a DIM, you can use on TanDM,” Fry said. “There are two cable tracks, and as people dream up new diagnostics, they can bring their own cables along with their diagnostics and replace them within a (work) shift. You can add cables in situ a lot more easily than the other positioners.”

The commissioning team still has some diagnostics to qualify, Fry added, including “specialty diagnostics” such as those used in National Security Applications Program experiments investigating radiation effects on Department of Defense DoD systems (see “Testing Materials for X-ray Effects”). The TanDM’s larger volume and access door compared to the DIMs make it well suited to house these larger diagnostic systems.

Technicians Install Diagnostic AssemblyTechnicians Greg Dituri (left) and Mike Morris install a National Security Applications XTRRA (x-ray transport and radiation response analysis) diagnostic assembly in TanDM 124 for the diagnostic’s initial commissioning test.

“The TanDM will allow us to provide cabling specific to our DoD customers needs,” said National Security Applications Program manager Brent Blue. “Instead of having to run in racks of diagnostics cabling for each experiment, our customers can insert their test articles into the TanDM and hook right into existing cabling to make their measurements. And the engineering improvements in TanDM should enable us to load and unload diagnostics much more quickly and efficiently.”

Along with speeding diagnostic exchanges, the TanDMs also provide flexibility in NIF shot operations by focusing on room-temperature experiments, freeing up the facility’s other target positioners for more integrated experiments with cryogenic fuel layers.

“The design, production, installation and commissioning of the first two TanDM positioners has been a tour de force by an exceptional team,” said NIF Facility Manager Doug Larson. “These complicated devices have come to life with very few issues, and are already an integral part of efficient target area operations.”

Participating in TanDM 124 commissioning along with Fry were Stanley Sommer, Jeremy Dixon, Ken Piston, Terry Malsbury, Arlen Rowe, Ben Hatch, Bob Ehrlich, Tom Kohut, Shannon Ayers, Rick Wilson, Mike Fedorov, and Sukhdeep Heerey.