Current Design and Short Status ATF2 Collimator - Mechanics at LAL Current Design and Short Status I-LINK meeting 2015 LAL-IN2P3-CNRS and Paris-Sud Orsay University - Sandry WALLON – 01 July 2015 1

Outline « First » mechanical design (SS) : short brief Alternative design in aluminum alloy : purpose ; pros and cons Chassis for collimator Manufacture, Checkings (vacuum, dimensions), mounting, Installation

1. « First » mechanical design (SS) : short brief Vacuum chamber (SS) Indium wire seal (copper gasket possible [SS chamber]) DN40CF Flange (copper gasket) 848 mm Transition foil (elastic part) Transition pipe Front wall Linear slide Jaw (mask) 600 mm Backing plate

Transition foil (elastic part) Rail (slide) Transition foil (elastic part) Front wall Rear wall Bellow Stem holder Carriage driven by ball-screw Rated linear slides disp. repeatability : +- 10 mm Stem with brazed flange

2. Alternative design in aluminum alloy : purpose ; pros and cons Vacuum chamber (Al alloy) Transition pipe (inside vacuum zone ; screwed to chamber) DN40CF Flange (SS) (screw to chamber ; indium wire crushed for tightness) Purpose of Al alloy Low production time to match LAL’s workshop work load Indium wire seal Smaller design (height) required by rail length issue

Pros : Production on time at LAL Lighter design (Chamber with its flanges : 15  7 kg) No welds Higher thermal conductivity Cons : Indium creeping (not worse than SS design) especially if beam hits entrance flange (but heat loss at very low level – see CST Nuria’s calculations [beam hitting the jaws])

Tansition part shift (SS/Al) : 30.7-5.3 mm

3. Chassis for collimator : open discussion Use of standard beam (Bosch system, …) : « building block style » Footprint to groung required, and way to fix the chassis (drawing from KEK)

4. Manufacture, Checkings (vacuum, dimensions), Mounting, Installation Main components already ordered (linear slides, bellows) Production at LAL’s workshop expected to start on Aug. Chassis to design and beams to order Checkings foreseen (and to be planned) at LAL Vacuum leak - outgasing ; 3D (dimensions, geometrical specs) Mounting ; checking jaws position / beam axis Installation goal : Nov. or Dec. 2015