1. Xbox and Structure testing news N. Catalan Lasheras, R. DeGiovanni, J. Giner-Navarro, G. Mcmonagle, I. Syratchev, B. Wooley, X. Wu 11.04.2014

2. Latest news from Xboxes. XL5 operating in Xbox1 experienced severe arcing in the gun – Prevented final conditioning in the TD26CC structure – HV connector for vacuum pump found damaged First klystron from CPI arrived on February Decision was taken to install XL5 in Xbox2 and CPI1 in Xbox1 to ensure enough power is available for dog-leg tests. Status of Xbox1 and Xbox2 installation and commissioning Meanwhile, analysis of the data collected in Xbox1 is ongoing N. Catalan Lasheras

3. Doesn’t look like same Box but no component damage Box at CERN Box leaving CPI CPI1 arrived on February 21 st safely to CERN

4. CPI unpackaging

5. Xbox1 status Removed XL5 Installed new CPI Klystron Two-load tree connected, pumped and baked All electrical and water connections completed yesterday Oil in modulator N. Catalan Lasheras Some additional shielding pieces to be added this afternoon diode testing of tube next week then acceptance test of tube with CPI after Easter

6. Summary All electrical and water connections completed yesterday Oil in modulator Some additional shielding pieces to be added this afternoon diode testing of tube next week then acceptance test of tube with CPI after Easter

7. Xbox2 status N. Catalan Lasheras XL5 klystron installed inside the new modulator Waveguide network connected to klystron – Temporary module with pulse compressor, and load for commissioning

8. Xbox2 preparation Safety doors and switches for personal protection installed Electrical protection around the solenoid LLRF and diagnostics moved operating temperature controlled rack. Cabling between racks ongoing TWT installation and connection Access doors and safety chain to the bunker Set-up of ceiling and additional shielding Connection of the remaining waveguide network in the bunker Safety files and RP authorization Conditioning of the RF network Installation of supports, spectrometer and diagnostics Installation of the first structure to be tested N. Catalan Lasheras

9. Xbox2 Diode testing has started to commission modulator N. Catalan Lasheras

10. Pulsing at short pulse width Managed to increase voltage reference on IGBT switches 1050 V Rep rate 50 Hz Heater current 20 amps Pulse width reference on modulator 0.5uS “noise” problems on waveform (IGBT switch cable, pulse tx ?) To be investigated (doesn't seem to be an earthing problem) Klystron gun breakdowns from time to time 1.5µS 318kV 208 Amps µPerveance = 1.16E-6

11. Reduced reference to 950 V IGBT, 50 Hz rep rate klystron operates in diode ok Pulse 0.5µs; Vkly 291kVPulse 0.6µs ; Vkly 291kVPulse 0.8µs; Vkly 285kV Pulse 0.5µS; Vkly 348kVPulse 0.6µS; Vkly 348kVPulse 0.8µS; Vkly 343kV Over the afternoon increased to 1150 V IGBT, 50 Hz rep rate klystron operates in diode ok

12. Commissioning status Still some modulator issues to be resolved Confident that klystron can run at this level until new CPI one arrives Happy that tube will “survive” until the arrival of new CPI tube Many modulator issues to be resolved with Scandinova before confidence top run unsupervised – Interlocks on vacuum to be verified – IGBT switch noise RF power after Easter Should be ok for crab cavity testing

13. Xbox3. 3D layout/integration almost finished

14. Gradient scaling law E 0 α t p -1/6 BDR 1/30 This normalized quantity represents the gradient if we would keep constant pulse length and constant BDR during the whole run Same conditioning level at different number of BD but comparable number of RF pulses. Conditioning seems to be more related with pulsing than with triggering breakdowns Comparison of the conditioning histories of two RF structures tested at CERN and KEK Normalized Gradient in conditioning histories

15. Thanks for your attention!!! N. Catalan Lasheras