Industry Days - Additive Manufacturing for RF/Microwave hardware

SPACE ATOMIC CLOCK IN ADDITIVE MANUFACTURING

17 Oct 2018, 14:30

30m

Newton 1&2 (ESA/ESTEC)

Speakers

Mr Philippe DENIS (THALES AVS France)Mr Philippe FAVARD (THALES AVS France)

Description

The atomic resonator – also called caesium tube – is a part of the atomic clock and allows to obtain a narrow, accurate and stable resonance used by electronics to lock the quartz oscillator on the atomic frequency. It is composed of an ultra-high vacuum Cs tube containing precision RF-elements. It is mainly composed of vacuum envelop, magnetic shielding, Cs oven, microwave cavity (Ramsey cavity), optical components and supports. Why atomic in additive manufacturing ? For reduction of the mass of the Atomic Resonator (material in Titanium Ta6V, optimization of the volume of vacuum envelop, reduction of number of pieces) and for reduction of the cost (production cost / sale cost). How ? By innovative technologies, identification of the design driver (vacuum function) and complete redesign of the vacuum envelop structure. Principle: The atomic resonator is built by additive manufacturing (with EBM process), structure in two half shell in titanium, copper deposit and mechanical refinishing for other functions: RF, optical then assembly of the two parts in only one step by brazing in a vacuum oven. Consequences: Very important mass reduction (> x2), reduction of number of pieces (250 -> 50), removing of alignment constraint during the integration of the optical and RF parts inside the atomic resonator, moving outside the vacuum envelop the functions without vacuum constraint (magnetic shielding…),accessibility of these functions actually under the vacuum and significant cost reduction (> x5). A demonstrator + sample tests have been manufactured to validate the selected concepts (ultra-high vacuum capability, brazing assemblies, copper / braze material deposit…).

Why your contribution is relevant for the event?

The atomic resonator is an RF component which regroups different specific requirements : ultra-high vacuum, dimension tolerances, coating... Some solution are proposed to reach these requirements with a such piece in additive manufacturing.