Intensity Based Laser Velocimeter

In his fiscal year 2024 Site-Directed Research and Development (SDRD) project “Intensity Based Laser Velocimeter”, principal investigator Brandon LaLone is developing a new velocimetry method for dynamic compression experiments. The prototype will be much simpler than existing Velocity Interferometer Systems for Any Reflector (VISARs) because it will leverage existing telecom industry devices, an approach that is completely unique to the shock community.

The NNSS has a long history of constructing velocimetry diagnostics for the National Weapons Laboratory, but many of the VISAR systems were built by retired scientists and are therefore difficult to maintain. Brandon and his team are undertaking this SDRD project to replace these existing VISAR systems, where the velocity changes are either too rapid or too high for Photon Doppler Velocimetry (PDV) to measure, with their proposed simpler prototype.

The planned prototype for the new velocimetry method will provide many benefits for the NNSS. In contrast to older systems, this prototype features a greatly simplified cavity, and all the fiber optic components replace the traditionally used free space beam farm. The resulting design is compact, and because it leverages existing telecom systems, it is much easier to assemble and operate, which also results in lower costs. Furthermore, the system has a fast response time of about 100 ps and it can resolve small velocity changes of less than 10 m/s.

Though this project is meant to prove the feasibility of a new velocimetry method, Brandon and his team are confident in the future success of the prototype. “The local team is available and well qualified to support the effort as proposed,” Brandon says. So far, the team has already designed the system and acquired materials to assemble the velocimeter, and they plan to eventually proof test on local dynamic platforms.

As Brandon and his team continue to do groundbreaking work in the shock industry, we wish them the best!