Clean SRF beamline assembly using rapid prototyping, machine vision and robotics

Over the past 20 years, the global SRF-based accelerating voltage has risen from 7GeV to 25GeV, and it is expected to rise to at least 40GeV within the coming decade. The proposed 250 GeV center of mass option for the ILC, which will be used for precision study of Higgs boson, requires roughly 7,800 SRF cavities. Each cavity requires a minimum of 3 particle free flange assembly (PFFA) operations during the string assembly, requiring skilled technicians and high labor costs. Technical Approach This project will develop rapid prototyping, machine vision and robotic technology to improve the clean assembly of a SRF cavity string. The so-called ‘particulate free flange assembly’ (PFFA) requires both the manual dexterity of a skilled technician (i.e. gasket insertion) as well as extensive diligence to blow each bolt hole clean. This repetitive process is based on a well-defined operation sequence, and thus is very well suited for robotic automation. Phase I Plans In Phase 1, we will review current cavity string assembly challenges, tooling, workflows, space requirements and equipment with engineers and technicians at JLab. We will design and 3D print a flange blow-off fixture, qualifying its particle shedding behavior in our class 100 clean room. We will procure and test a contactless, laser-based machine vision system which can locate the position and orientation of a cavity flange. Using our Kuka robot installed on-site, we will demonstrate the ability to precisely locate flange holes in a known/fixed reference frame. We will then integrate these tasks with the objective of automating the ionized blow off procedure. Commercial Applications and Other benefits The development of SRF cavities for use in particle accelerators has benefited from a close and extensive collaboration between research institutions and industry. The market for medical and industrial accelerators currently exceeds $3.5 billion dollars a year, and it is growing at more than 10% annually. While Superconducting Radio Frequency (SRF) accelerators are a small fraction of the total accelerator market, there are significant demands to reduce the labor costs and improve the yield of cryomoduleinstalled cavities. This project will further that objective by utilizing prototyping, robotic and machine vision tools to automate the cryomodule assembly process. Furthermore, clean, high precision assembly robots can be used for other operations, such as normal conducting cavity assembly.