Hydroformed MultiCell Cavities Update Waldemar Singer DESY Peter

Hydroformed Multi-Cell Cavities. Update Waldemar Singer, DESY Peter Kneisel, JLab

It was proven that hydroformed single cells reached Eacc up to 40 MV/m after EP and up to 35 MV/m after BCP. Currently the work is concentrated on multi-cell and 9 - cell cavities Hydroformed at DESY and dressed with end tubes at Jlab 2 -cell units W. Singer, P. Kneisel, TTC Meeting, February 28 - March 3 2011, Milano, Italy

DESY 2 -cell "DESY_ 2_2" 1, 00 E+11 Test #1 Q 0 1, 00 E+10 Q - drop 1, 00 E+09 0 5 10 15 20 25 30 Eacc [MV/m] First RF test of the hydroformed 2 cell unit 2 H 2 after post purification at 1200°C and 50µm BCP

DESY 2 -cell seamless cavity- 2 H 3 Q 0 vs. Eacc 1, 00 E+11 Test #3 a Q 0 1, 00 E+10 1, 00 E+09 0 5 10 15 20 25 30 35 40 Eacc [MV/m] Qo(Eacc) performance of the one of 2 -cell hydroformed cavity. Typically after ca. 200 -250 µm BCP or EP and baking reached Eacc=30 -35 MV/m

Three 9 -cell cavities from hydroformed at DESY units completed at E. ZANON (Z 145, Z 163 and Z 164) Four 9 cell cavities available now Z 145 Z 163 Z 164 Z 145 One 9 -cell cavity from hydroformed at DESY units completed at JLAB W. Singer, P. Kneisel, TTC Meeting, February 28 - March 3 2011, Milano, Italy

RF Performance: Z 145 T=2 K Surface DESY: treatment at 40 mm BCP, 800 °C heat treatment, tuning; 170 mm EP, ethanol rinsing, 800 °C heat treatment; 48 mm EP, HPR, Individual cells have performance between 30 MV/m and 39 MV/m W. Singer, P. Kneisel, TTC Meeting, February 28 - March 3 2011, Milano, Italy

Cavity Z 145, all RF tests Test 1: after 40 mm BCP, 800 °C, 170 mm EP, 800 °C; 48 mm EP Test 2: after add. baking at 120°C for 48 h Z 145 Test 3: after new feedthroughs and HOM coupler antennas mounted Test 4: after add. 10 µm EP W. Singer, P. Kneisel, TTC Meeting, February 28 - March 3 2011, Milano, Italy

Hydroformed cavity Z 145 is installed in module 3***/ACC 1 in FLASH Denis Kostin, MHF-SL, DESY Hydrof. Cav. Z 145 W. Singer, P. Kneisel, TTC Meeting, February 28 - March 3 2011, Milano, Italy

Cavity Z 163 in preparation at DESY. Final EP is foreseen. Status: 800°C annealed, tuned by new tuning procedure, main EP done W. Singer, P. Kneisel, TTC Meeting, February 28 - March 3 2011, Milano, Italy

Tuning of Z 163 by radial deformation. Allows significant change of the frequency (few MHz) keeping the cavity length W. Singer, P. Kneisel, TTC Meeting, February 28 - March 3 2011, Milano, Italy

Cavity Z 164 RF tests of three 3 -cell units Three 3 cell units are tested individually at JLab After BCP and post-purification at 1200°C for 3 hrs with titanium and subsequent BCP. The total material removal is ca. 250 µm. W. Singer, P. Kneisel, TTC Meeting, February 28 - March 3 2011, Milano, Italy

After completing at E. Zanon JLab tested the completed 9 -cell cavity Z 164 Qo 1, 00 E+11 1, 00 E+10 1, 00 E+09 0 5 10 15 Eacc, MV/m 20 25 30 Z 164 first RF test after 50 µm BCP + HPR done at JLab. Limited by Q-drop at 26. 4 MV/m, no quench. Next step is EP W. Singer, P. Kneisel, TTC Meeting, February 28 - March 3 2011, Milano, Italy

Poster THP 043 LINAC 08 Cavity bottom inside surface Relation of Eacc to the tube fabrication method (Tube bottom) Bottom cell Top cell (tube top) Cavity top inside surface Tube after spinning T-map on 3 -cell hydroformed cavities from spun+ flow formed tubes at Eacc = 27 MV/m, (JLab) indicating several hot-spots in the equator area, mostly on the top cell. Good Eacc results, nevertheless the tubes can be made better W. Singer, P. Kneisel, TTC Meeting, February 28 - March 3 2011, Milano, Italy

EP or BCP in combination with CBP seems to be a most appropriate treatment for seamless cavities Inside surface after CBP Centrifugal Barrel Polishing CBP at DESY More to Barrel Polishing: Talk of Charlie Cooper tomorrow

W. Singer, P. Kneisel, TTC Meeting, February 28 - March 3 2011, Milano, Italy

Last development: Tubes of Black Lab + Wah. Chang supported by DESY. Heavily deformed billet, processed for fine grain structure Shaped by forward extrusion and flow-forming Black Lab. Long tube 1, 3 GHz cells hydroformed at DESY from Black Lab tubes Completed at JLab 9 -cell cavity. In preparation for test at JLab W. Singer, P. Kneisel, TTC Meeting, February 28 - March 3 2011, Milano, Italy

Conclusions • Fabrication of the 9 -cell cavities (3 x 3 units) of TESLA like shape by hydroforming is proven. • Hydroformed 9 -cell cavity installed in cryomodule is in FLASH operation (proof of principle is successful) W. Singer, P. Kneisel, TTC Meeting, February 28 - March 3 2011, Milano, Italy