1 / 8

Main magnet apertures (baseline) Vacuum chamber geometry for dipoles optimization parameters

First design of a PS2 prototype vacuum chamber Edgar Mahner thanks to Sebastien Blanchard, Cedric Garion, Giuseppe Foffano. Main magnet apertures (baseline) Vacuum chamber geometry for dipoles optimization parameters geometry, FE model, behavior under vacuum first prototype fabrication

raina
Download Presentation

Main magnet apertures (baseline) Vacuum chamber geometry for dipoles optimization parameters

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. First design of a PS2 prototype vacuum chamberEdgar Mahner thanks to Sebastien Blanchard, Cedric Garion, Giuseppe Foffano • Main magnet apertures (baseline) • Vacuum chamber geometry for dipoles • optimization parameters • geometry, FE model, behavior under vacuum • first prototype fabrication • Possible bakeout solutions • Conclusions Edgar Mahner

  2. PS2 main magnet apertures • Proposal for outer dimensions of the vacuum system in the main magnets, now including alignment and heating jackets! • Status 16.04.2009 (MB, PS2 meeting) • Dipoles half sizes: 60 mm horizontal, 40 mm vertical • Quadrupoles half sizes: 65 mm horizontal, 45 mm vertical • First consideration for a PS2 prototype dipole vacuum chamber by C. Garion Dipole gap: 80  120 mm2 Dipole length: 4.20 m Installation/alignment: ≈1 mm (tbs) Bakeout system: ≈5 mm thick (tbs) C. Garion (April 2009)  Maximum outer dimensions of the dipole vacuum chamber: ≈68  108 mm2 Edgar Mahner

  3. Principle of the vacuum chamber geometry dy • Objective: vacuum chamber for maximum h/v beam aperture • Shape close to a rectangular (shoe-box type) vacuum chamber with following main parameters used for calculations: • Thickness, dy, dx • Main assumptions: • Stainless steel (almost mandatory) • Plane stresses (axial free: required for a baked solution) • No installation pre-stress R=5 Vertical aperture reduction (or equivalent thickness) 34 C. Garion (April 2009) dx 54 Edgar Mahner

  4. Parameters • Assumption • The aperture is defined by the inner wall of the vacuum chamber minus a geometrical tolerance, 0.5 mm assumed (tbc) • This tolerance could be, for example, a shape and/or straightness deviation; under discussion with EN-MME • Optimization guideline • Find the smallest vacuum chamber thickness to obtain the largest beam aperture but satisfying mechanical stability (stiffness). C. Garion (April 2009) The minimum vertical aperture reduction is obtained for a stainless steel wall thickness of 2mm; dy = 0.65 mm; dx = 0.1 mm Edgar Mahner

  5. Geometry, FE model, andMechanical behavior under Vacuum • Concept: the vacuum chamber is slightly biconvex, under vacuum it becomes almost flat no aperture reduction • Stability checked; equivalent (von Mises) stress under vacuum: 100 MPa • Stainless steels 304L: 175 – 200 MPa; 316L: 200 MPa; 316LN: 300 MPa • Safety factor with respect to the yield stress? • But: eddy current forces have to be estimated during the magnet ramp (1.7 T/s) and considered for the design. = 31.35 mm C. Garion (April 2009) 2 = 53.9 mm • Obtained beam apertures • Vertical 62.7 mm • Horizontal 103.8 mm • not including geometrical tolerances of the vacuum chamber Edgar Mahner

  6. PS2 prototype vacuum chamber – to be coated Three chambers for coating tests (Cu, a-C, TiZrV) 316LN st.st. (2 mm wall thickness) 3020  108  68 mm3 (with two DN 150 CF) Reduced length  fabrication is possible @ CERN DRAFT under discussion with EN-MME G. Foffano (June 2009) Edgar Mahner

  7. PS2 prototype vacuum chamber under vacuum • Concept: the vacuum chamber is flat, under vacuum it becomes slightly biconcave  small aperture reduction G. Foffano (June 2009) Edgar Mahner

  8. Possible bakeout solutions for PS2 dipoles • Conclusions • A 5 mm thin bakeout system, which was a first assumption, needs development work to increase its reliability (problems found in LHC (warm magnets) with 4.3 mm system); a 6.7 mm thin bakeout system is o.k. (good experience, e.g. in LEIR). • A 1 mm gap between the bakeout equipment and the dipole magnet seems (too) small, risk to damage it during closure of the upper magnet cover. • Important assumption (agreed with GdR): bolted-type PS2 dipoles and quadrupoles, avoids to slide vacuum chambers with heating elements into magnets, no need to cut/weld flanges (very important in many aspects) • Next steps: material/dimensions/fabrication methods/tolerances of vacuum chambers, deformation under vacuum as well as bakeout options need more studies to optimize for maximum beam aperture but also to build a (very) reliable system. Blue: dipole vacuum chamber Red: dipole gap (120  80 mm2) Blue: dipole vacuum chamber Red: dipole gap (120  80 mm2) S. Blanchard (June 2009) Edgar Mahner

More Related