STATIC AND MODAL BEHAVIOUR OF THE CLIC MAIN BEAM BPM SUPPORTM. Esposito, EN-MME

The research leading to these results has received funding from the European Commission under the FP7 Research Infrastructures project EuCARD

CLIC Test Module meeting 7th March 2012

The Model 2

BPM Support(304L)

Alignment target Support (316L)

Flange

Upstream body (316LN)

MainBody(316LN)

Intermediate body (316LN)

Chamber adapter (304L)

Mass of BPM Support: ~0.2kgMass of BPM Assembly: ~0.7kg Mass of Align. Support: ~0.14kg

M. Esposito, Test Module Meeting, CERN 7 March 2012

Boundary Conditions3

M. Esposito, Test Module Meeting, CERN 7 March 2012

Support is fixed to the magnet & the chamber adapter is fixed to the vacuum chamber which are considered fixed

The BPM assembly is considered free on this side

Static Structural Analysis4

M. Esposito, Test Module Meeting, CERN 7 March 2012

Effect of weight: 0.13 μm center 0.4 μm max

Vertical stiffness: 55 N/μm center 41 N/μm min

Lateral stiffness: 15.5 N/μm center 9.1 N/μm min

Longitudinal stiffness: 769 N/μm center 250 N/μm min

Modal Analysis5

M. Esposito, Test Module Meeting, CERN 7 March 2012

1st mode (yaw)

2nd mode(pitch)

3rd mode (yaw with torsion)

f1=650 Hz f2=903 Hz f3=1506 Hz

Comparison between with and without BPM support

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M. Esposito, Test Module Meeting, CERN 7 March 2012

WITH SUPPORT WITHOUT SUPPORTcenter worst center worst

STATIC Effect of Gravity

[μm]

0.13 0.4 0.7 1.4

Vertical stiffness [N/μm]

55 41 9.1 7.7

Lateral stiffness [N/μm]

15.5 9.1 10 8.3

Longitudinal stiffness [N/μm]

769 250 909 714

f [Hz] shape f [Hz] shapeMODAL Mode 1 650 yaw 529 pitch

Mode 2 903 pitch 585 yaw

Mode 3 1506 yaw (torsion)

960 roll

Comparison between BPM fully fixed to chamber & fixed only longitudinally

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M. Esposito, Test Module Meeting, CERN 7 March 2012

FIXED TO CHAMBER FIXED LONGITUDINALLY

center worst center worstSTATIC Effect of

Gravity [μm]

0.13 0.4 0.67 0.67

Vertical stiffness [N/μm]

55 41 15.4 15.4

Lateral stiffness [N/μm]

15.5 9.1 1.7 0.9

Longitudinal stiffness [N/μm]

769 250 769 769

f [Hz] shape f [Hz] shapeMODAL Mode 1 650 yaw 194 lateral

Mode 2 903 pitch 660 pitch+vertical

Mode 3 1506 yaw (torsion)

903 pitch

Conclusions8

M. Esposito, Test Module Meeting, CERN 7 March 2012

•A static structural and a modal analysis of the MB BPM support has been

performed and results show that the structure is quite robust against

external forces and very stiff

•The BPM support gives little help in terms of modal behaviour, which is

already very good, but it gives a significant contribution in terms of

vertical stiffness

•Great attention has to be given to the rigidity of the beam chamber

connected to the BPM because it is responsible in major part of the

robustness and stiffness of the whole structure

M. Esposito, Test Module Meeting, CERN 7 March 2012

SPARE SLIDES

Displacement during installation

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M. Esposito, Test Module Meeting, CERN 7 March 2012

Support pulls BPM 10 microns horizontally

Support pulls BPM 10 microns vertically