The mechanical design of a bunched beam stochastic cooling tank for the FNAL Tevatron

The stringent alignment required for successful bunched beam stochastic cooling in FNAL´s Tevatron necessitates the design and manufacture of a complex vacuum compatible mechanical alignment system. The design presented uses remote motion control to provide a positioning system with four degrees of freedom for placing two symmetric pickup loop arrays about the proton beam and with two degrees of freedom for aligning the arrays relative to each other. The system provides a 7.62 cm aperture between arrays during injection and a 1.90 cm aperture during operation while maintaining alignment between arrays within 50 μm. The system also allows precise remote longitudinal adjustment between pickup arrays with 0.002 μm resolution via a piezoelectric crystal inchworm motor in vacuum. Discussion includes the manufacture and installation of four complete pickup and kicker systems in the FNAL Tevatron