1. Simulation of the CLIC Compressor Cavity, Luca Dassa (EN-MME/ES)10/04/2013 1 di 10 Simulation of CLIC Pulse Compressor Cavity Report, April 10th, 2013 Luca Dassa (EN/MME-ES)

2. Simulation of the CLIC Compressor Cavity, Luca Dassa (EN-MME/ES)10/04/2013 2 di 10 Experimental results

3. Simulation of the CLIC Compressor Cavity, Luca Dassa (EN-MME/ES)10/04/2013 3 di 10 Thermal analysis Model calibration Emissivity of the Ni coating: not available (light grey surface, not shining, higher value expected than polished Ni, higher than the one from a SS316L raw new machined flange)

4. Simulation of the CLIC Compressor Cavity, Luca Dassa (EN-MME/ES)10/04/2013 4 di 10 Thermal analysis Thermal gradients Temperature difference Max temperature difference: 380 ° C Thermal gradients during heating 1.There are not thermal gradients into the PC cavity component. 2.The maximum gradient into the cooling cap is about 30 °C Thermal gradients during cooling 1.There are not thermal gradients into the PC cavity component. (Maximum ΔT=15 °C) 2.Into the 316LN cooling cap the maximum gradient is about 85 °C

5. Simulation of the CLIC Compressor Cavity, Luca Dassa (EN-MME/ES)10/04/2013 5 di 10 Static analysis heating 3.2 mm Cu OFE 316LN 0.43 mm

6. Simulation of the CLIC Compressor Cavity, Luca Dassa (EN-MME/ES)10/04/2013 6 di 10 Static analysis cooling The two components are separately studied. The order of magnitude for differential deformation is not comparable with the observed displacement (sub-millimetre range). Vertical displacement Cu OFE 316LN The two components are separately studied. The order of magnitude for differential deformation is not comparable with the observed displacement (sub-millimetre range).

7. Simulation of the CLIC Compressor Cavity, Luca Dassa (EN-MME/ES)10/04/2013 7 di 10 PARTIAL CONCLUSIONS heating high difference in temperature between the PC Cavity (Cu OFE) and Cooling Cap (316LN) up to 380 °C high difference in thermal dilatation (vertical): up to 3.2 mm no odd deformation of the Cu component (no thermal gradients) cooling highest gradient on the Cooling Cap during cooling: up to 85 °C order of magnitude in displacement/deformation not comparable with the shift Partial conclusions REMARKS results can be used for qualitative comparison between alternatives but cannot be used to predict accurately how the structure will behave removing high temperature difference and high thermal gradient will decrease the risk of relative displacement between components

8. Simulation of the CLIC Compressor Cavity, Luca Dassa (EN-MME/ES)10/04/2013 8 di 10 Further analyses (1) The difference in vertical displacement is about 1.4 mm Low Cu emissivity! The heat exchange is driven by radiation No interesting advantages

9. Simulation of the CLIC Compressor Cavity, Luca Dassa (EN-MME/ES)10/04/2013 9 di 10 The difference in vertical displacement is about 1.5 mm Further analyses (2) No interesting advantages

10. Simulation of the CLIC Compressor Cavity, Luca Dassa (EN-MME/ES)10/04/2013 10 di 10 CONCLUSIONS lower ramp-up reduces the temperature difference (and consequently the displacement difference) no significant improvement manufacturing the Cooling Cap in Cu OFE no significant improvement adding shields Conclusions REMARK e-beam welding, if possible, can remove any thermal gradient or difference in temperature