1 Workshop on Vacuum System Design for Synchrotron light Source ALBA - Barcelona, Sept New trends in the vacuum design and technology

2 Workshop on Vacuum System Design for Synchrotron light Source ALBA - Barcelona, Sept Generalities The new synchrotron sources are now designed and completely dedicated for the users. –Maximum operation time for the users Reliability of the ring Fast conditioning after installation of new components Recovery after failure –Performances and quality of the delivered beam Stability Beam lifetime

3 Workshop on Vacuum System Design for Synchrotron light Source ALBA - Barcelona, Sept Evolutions of the vacuum system design Link to the beam performance –Low emittance  low   short bunch length Wide bunch spectrum Sensitivity to impedance at tens of GHz –Low cost machine Reduced bore radius Reduced vacuum vessels aperture –Increased asymmetry of the chamber cross section

4 Workshop on Vacuum System Design for Synchrotron light Source ALBA - Barcelona, Sept Improving the conditioning time Bake-out stays the best way to outgassing rate –Bake out of complete cell of the ring ex-situ and installation under vacuum (SLS, ASP, Diamond,..) Reduces the quantity of bellows Needs the opening of the magnets in case of intervention Use in a extended way NEG coating at least for the ID vacuum vessels. This allows a fast availability of the beamline after installation of a new insertion device. (Fast decrease of the bremsstralung radiation)

5 Workshop on Vacuum System Design for Synchrotron light Source ALBA - Barcelona, Sept NEG cotaing Distributed pumping to composite the small conductance of the vessels due to small aperture Reduction of the quantity of conventional pumps installed on the ring especially SIP Need of in-situ bake-out Possibility to make the NEG coating as an industrial process Do the laboratories need to equip themselves with coating facility?

6 Workshop on Vacuum System Design for Synchrotron light Source ALBA - Barcelona, Sept Design and manufacturing of the vacuum system More and more the components and whole parts of the synchrotron sources are ordered as turn key contracts –Final design made by the manufacturer from specifications –Installation made by the manufacturer –The maintenance? Staff of the vacuum group

7 Workshop on Vacuum System Design for Synchrotron light Source ALBA - Barcelona, Sept Materials Stainless steel (problem of 316 LN procurement) Extruded aluminium profiles used for long straight vacuum vessels (coupled with NEG coating) Glidcop or OFHC copper –New ID’s (in-vacuum undulators and SW) with high radiated power. Design of the components of the front ends.

8 Workshop on Vacuum System Design for Synchrotron light Source ALBA - Barcelona, Sept Interactions between vacuum system and the e- beam The fine design of the vacuum vessels must take into account the impedance issues –Material (Resistivity, roughness,…) –Assembly design small cavities must be avoided