A Robotic Inspection and Assembly Workcell for SRF Cavities

The production of high-Q superconducting radio frequency (SRF) cavities involves a complex
chain of fabrication and inspection operations. Currently, much of this demanding work is
performed manually within the tightly controlled environment of a production cleanroom.
However, as the design precision and cleanliness requirements of modern SRF cavities have
increased, this “human factor” has emerged as the biggest contributor to sub-optimal cavity
performance. To address this problem, a robotic assembly Workcell is proposed. This Workcell
is predicated on a pair of six-axis articulating arm robots, active registration/positioning fixtures
and a collection of non-contact metrology tools. Automated end effector exchange allows the
robots to select the appropriate tool for each specific tasks. The Workcell is thus able to
determine the topography of an incoming cavity, inspect its welds, clean its critical surfaces, and
align/attach external flanges. The Workcell is fully compatible with Class 10 cleanrooms and its
modular design allows it to be rapidly reconfigured to accommodate different cavity geometries
and/or reprogrammed to perform new tasks.
SRF cavities are essential elements of almost all modern particle accelerators; the proposed
automated Workcell will serve as a powerful enabling technology and its inherent operational
flexibility will allow its work portfolio to evolve and expand. Eventually, the Workcell can be
adapted to perform higher-level operations associated with accelerator cavity string assembly. In
the near term, the multi-billion dollar Proton Improvement Plan II (PIP-II) now underway at the
Fermi National Accelerator Laboratory will be the Workcell’s primary market. Future
accelerators such as the planned International Linear Collider along with private sector
manufacturers represent an even larger commercial opportunity.