LLE's Mechanical Engineering Group

November 2009

Block of metal

Initial block of metal on the milling machine table

Programming the milling machine

Programming the milling machine to carve the metal into the finished part

Finished part

Finished part

The Mechanical Engineering (ME) Group provides a full range of mechanical design, engineering, fabrication, assembly, and testing capabilities. They specialize in designing, fabricating, and constructing unique and precise components and structures and are staffed by 26 full-time employees and 5 students. The full-time employees consist of 13 mechanical engineers, 2 manufacturing engineers, 6 technicians, and 5 machinists.

Highly skilled in Computer Aided Design (CAD) and Finite Element Analysis (FEA) to support research projects, the group's primary responsibility is supporting the complex mechanical and optical equipment used in the OMEGA and OMEGA EP laser systems. This involves fabricating new equipment, repairing worn or damaged equipment, and manufacturing replacement parts. This sometimes means fabricating new equipment if something malfunctions or does not fit properly. In addition, both laser systems require extensive diagnostics that are custom-designed by the ME Group and made in LLE's machine shop. These efforts have been strengthened by the addition of computer numerically controlled (CNC) mills. Tool paths for parts to be machined are generated directly from the 3-D models developed by the mechanical engineers. The CNC mills then use the tool paths to automatically generate new parts with minimal intervention of an operator. The primary advantage of the computer-controlled machinery is that it allows for greatly improved accuracy, efficiency, productivity, and safety over manual forms of metal-working equipment. These advances have made it possible for the shop to produce higher-quality products, to substantially increase productivity, and to maintain a high degree of safety.

The mechanical engineers are currently working on developing and assembling a new moving cryostat (MC) for use on OMEGA. MC's are used to transport individual cryogenic targets within the laboratory from where they are assembled to an area below the Target Bay, where the targets are inserted into the OMEGA target chamber. The mirror-like appearance of the MC, constructed of copper, requires precise and accurate lapping, cleaning, and polishing skills to achieve the required fits and finishes. When the MC first arrived at LLE from the vendor, the finishes were not smooth enough; to ensure maximum reflectivity, refinement, and performance, LLE machine shop staff hand-sanded, buffed, and cleaned every piece to the required specifications. The MC is now exclusively manufactured at LLE and is capable of achieving the precise, stable, and accurate positioning requirements for cryogenic targets located at OMEGA's target chamber center.

In addition to serving the OMEGA Laser Facility, the ME Group develops, assembles, and supports diagnostic instruments for a variety of national clients, including Lawrence Livermore National Laboratory, Los Alamos National Laboratory, Sandia National Laboratory, and other collaborators. These clients look to LLE and the ME Group to provide them with high-quality products featuring state-of-the-art machining technology and superb engineering services.

Inner and intermediate shrouds

These components comprise the inner and intermediate shrouds for the new moving cryostat.

University of Rochester students and professional staff (with development or research projects at LLE) have access to a student machine shop at LLE. The shop can accommodate up to 60 program participants. These users must take an introductory course highlighting general shop procedures and safety training, and then receive on-going instruction and support from LLE machine shop staff as their individual projects progress.

Although the pace and enormous range of activities frequently takes on the intensity of an emergency room, the staff of the ME Group takes pride in the spirit of creativity, ongoing education, and technologically advanced challenges that govern each extraordinary work day.