HOM Damped cavities. V. Serrière, J. Jacob, A. Triantafyllou, B. Ogier, L. Goirand

Transcription

1 HOM Damped cavities V. Serrière, J. Jacob, A. Triantafyllou, B. Ogier, L. Goirand *This work, carried out within the framework of the ESRFUP project, has received research funding from the EU Seventh Framewok Programme, FP7. Accelerator & Source Division Annual Workshop

2 Copper prototype design aspect No gap bewteen the ridges and the cavity body, coupling section e-beam welded to the cavity. In the ridge zones, the electrical continuity will be established by means of RF fingers. Cavity body End disc Coupling section HOM absorber Based on 500 MHz BESSY, MLS, ALBA design [E. Weihreter et al.] Intermediate section Accelerator & Source Division Annual Workshop

3 Initially specified mechanical design & manufacturing procedure applied by RI Research Instruments e-beam welding of HOM coupling sections e - Brazing: -cooling circuits -outlets -flanges Frequency tuning Brazing end plates Continuous, no gap e - Accelerator & Source Division Annual Workshop

4 RI Research Instruments cavity End disc Outlets E-beam welding of the water box on coupling section [Photos: courtesy of RI research intruments] Accelerator & Source Division Annual Workshop 2011

5 RI Research Instruments cavity Cavity before e-beam welding Beam stop: -5 mm on the radius [Photos: courtesy of RI research intruments] Accelerator & Source Division Annual Workshop

6 RI Research Instruments cavity Cavity after e-beam welding & before machining of the beam stop [Photos: courtesy of RI research intruments] Accelerator & Source Division Annual Workshop

7 RI Research Instruments cavity Cavity after machining of the beam stop Helium leak detection - Vacuum tight Pores <0.2 mm on the weld seam [Photos: courtesy of RI research intruments] Accelerator & Source Division Annual Workshop

8 RI Research Instruments cavity RI proposed to repair the welding by a smooth laser weld Laser weld on sample Micrograph of laser weld Laser weld original root e-beam weld [Photos: courtesy of RI research intruments] Accelerator & Source Division Annual Workshop

9 RI Research Instruments cavity Cavity after laser welding [Photos: courtesy of RI research intruments] Accelerator & Source Division Annual Workshop

10 RI Research Instruments cavity Next steps: brazing of the end discs (preparation finalized this week ) brazing of the cavity body (preparation finalized this week ) RF tuning brazing of the end discs on the cavity body FAT & delivery at the ESRF: March 2011 Accelerator & Source Division Annual Workshop

11 Alternative design proposed by SDMS applied by SDMS and CINEL e-beam welding Brazing Brazing & Brazing Brazing Accelerator & Source Division Annual Workshop

12 Alternative design proposed by SDMS applied by SDMS and CINEL Final assembly by e-beam welding Accelerator & Source Division Annual Workshop

13 SDMS cavity Machining of the cooling circuit of the cavity body and the cover. Accelerator & Source Division Annual Workshop

14 SDMS cavity The end disc marguerite before e-beam welding Accelerator & Source Division Annual Workshop

15 SDMS cavity Start of the e-beam welding. helium leak detection & water cooling circuit test. The cavity body and the end discs are water tight!!! Accelerator & Source Division Annual Workshop

16 SDMS cavity Then the cavity body is cut in three parts. Accelerator & Source Division Annual Workshop

17 SDMS cavity e-beam welding of coupling section and outlets from inside. Accelerator & Source Division Annual Workshop

18 SDMS cavity e-beam welding of the three sectors Machining of the final diameter Accelerator & Source Division Annual Workshop

19 SDMS cavity Helium leak detection One coupling section is not vacuum tigth SDMS proposed to solve the problem by a further e-beam welding from inside (under investigation) Accelerator & Source Division Annual Workshop

20 SDMS cavity Next steps: Repair of the leak by e-beam welding under investigation RF tuning procedure e-beam welding of end discs FAT & delivery at the ESRF: March 2011 Accelerator & Source Division Annual Workshop

21 CINEL cavity CINEL has already machine all the part of the cavity Assembly by e-beam welding started in October FAT & delivery at the ESRF expected for May2011 Accelerator & Source Division Annual Workshop

22 CINEL cavity e-beam welding the water box covers of the end-discs e-beam welding of the water box covers of the three sectors Accelerator & Source Division Annual Workshop

23 HOM dampers 1) Ferrite brazed on copper plate 2) Copper plate brazed on stainless steel 3) Cover TIG welded RI and CINEL follow the initial design, SDMS prefers to braze the ferrite directly on stainless steel. Accelerator & Source Division Annual Workshop

24 IR tests Experimental set up for the RI and CINEL copper brazed ferrites : - IR radiators provide the power estimated equal to 5W/cm2. Results for RI plates: planarity measurement 180o rotation first plate x (mm) y (mm) z (mm) x Accelerator & Source Division Annual Workshop

25 IR tests Experimental set up for the SDMS stainless steel brazed ferrites : - The cooling system is drilled on the stainless steel base. - The ferrites are brazed on the stainless steel. Results : Reference image for bad quality brazing 65 o C 59 o C 61 o C Accelerator & Source Division Annual Workshop

26 Conclusions The chalenging fabrication processes of the three prototypes progresses with some troubles Expected delivery time for cavity + intermediate sections + HOM dampers: RI research intruments: March 2011 SDMS: March 2011 CINEL: May 2011 Followed by RF conditioning in the test stand Beam conditioning in place of cavity 5 on the storage ring More good news next year Accelerator & Source Division Annual Workshop