CLIC XBAND STATUS AND MANUFACTURIN G CONSIDERATIO NS

CLIC X-BAND STATUS AND MANUFACTURIN G CONSIDERATIO NS N. CATALAN LASHERAS, A. MAGAZINIK, P. MORALES SANCHEZ, J. SAUZA BEDOLLA

OUTLINE 01 02 03 04 CLIC baseline structures Future prototypes RF X-band components A word on Xboxes

CURRENT PRODUCTION BASELINE AT CLIC Based on ultra-precision machining with diamond tools and diffusion bonding of the cells Gold brazing for parts with access to RF volume Silver alloys for brazing of cooling blocks Takes 10 - 11 months to do a full cycle 20 - 24 weeks for machining 6 - 12 weeks for assembly

More than 30 prototypes at 12 GHz made for high power tests and operation using this baseline. About 20 tested in high gradient and reaching 100 -120 MV/m WHAT HAVE WE DONE FOR CLIC? 2 -3 more in operational machines About five more done by collaborations using CLIC and other manufacturing processes, Crab cavities done by Lancaster PSI T 24 using Swiss. FEL method (vacuum brazing) SLAC prototype made of halves. (Silver Brazing) SINAP deflector. Also vacuumbrazed Smart. Light prototype by Eindhoven Probe prototype by Lancaster in S-band KEK parallel development in Asia with ~15 prototypes. Similar baseline

SMART LIGHT STRUCTURE X-band bunching-accelerating structure for Compton source Structure designed and built by Eindhoven with CERN recipes • Using CERN alignment and weighting tool • Assembled by CERN and Eindhoven staff • Tunned at CERN (without Eindhoven presence due to COVID 19) • Arrived. Waiting for news

X-BAND LINEARIZER ~1 m-long structure. Linearizer for CLARA in UK Two units already operating in Elettra (Trieste) and two in PSI (Villigen) Made from three bonded stacks of ~33 cm Final brazing with interlock disks Expected to be finished in Feb 2021 H. Bursali and R. Wegner

We know that assembling full prototypes with damping, WHAT’S NEXT? absorbers and Wakefield monitors is achievable but not optimized Up to know, two different approaches with different results Frequent leaks and repair cycles Labor- intensive Alignment between structures outside tolerance Damping features seem to degrade performance We also suspect, bonding cycle imposes geometry deformations in the final cells. Not harmful for final performance May require tuning Spoils the machining quality And we still have the advantage of hard copper vs. soft copper Two alternative assemblies

INTEGRATED STRUCTURES MADE OF EB-WELDED HALVES Prototype manufactured by SLAC and tested to 100 MV/m. New damped prototype arrived from SLAC Brazed design • • • RF design made by H. Zha and A. Grudiev. Mechanical design finished by A. Solodko. Asking for quotes Eb-welding far from RF area. Hard copper Less number of pieces to be assembled Integrated design Long time of machining. Lower yield. Higher price Qualification piece required Systematic alignment errors

INTEGRATED RECTANGULAR DISKS Bend waveguide design made by H. Zha and A. Grudiev Mechanical version by A. Solodko including vacuum, cooling and silicon carbide loads. Bonding test. Failed due to silicon carbide height

PROBE STRUCTURE § S-band structure for medical therapy § Structure designed and built by Lancaster with CERN procedures § Similar bonding area to CLIC prototype § No silicon carbide § Leak tight § Using special alignment and weighting tool § Assembled by CERN and Lancaster staff § To be tunned at CERN by Lancaster students in the next weeks

BRAZING DESIGN FOR INTEGRATED DISKS Re-use spare disks designed for brazing before 2010 Compare different brazing materials, heat cycles, material/void ratio Destructive tests to assess quality and bond Brazing tests in spare disks Re-design the disks for brazing Procurement and fabrication of a mechanical mock-up RF/Mechanical design of a full structure Fabrication and test

COMPONENTS. HTTPS: //ESPACE. CERN. CH/PROJECT-CLIC-XBANDPRODUCTION/OPEN%20 HARDWARE%20 XBAND%20 COMPONENTS/FORMS/ALLITEMS. ASPX 3 d. B splitter Double height hybrid Pumping port 60 d. B directional coupler

COMPONENTS. NOT YET IN OPEN HARDWARE Variable phase shifter Variable power splitter 50 MW window Low power terminator

COMPONENTS. SPIRAL LOAD 3 D printed in St. St and Titanium. Tested to high gradient > 35 MW Compact and unexpensive. New design to optimize printing underway Maybe difficult to machine

39 users from around 18 laboratories and companies Hits OPEN HARDWARE 1200 1000 800 600 400 200 0 60 50 40 30 20 10 0 Unique Users 20 18 20 -02 18 20 -04 18 20 -06 18 20 -08 18 20 -10 18 20 -12 19 20 -04 19 20 -06 19 20 -08 19 20 -10 19 20 -12 20 20 -04 20 20 -06 20 20 -08 20 20 -1 2 Monthly Hits Unique Users

FULL CLIC MODULE FOR KLYSTRONBASED MACHINE TBC Will use final integrated structure to build superstructures Will need two BOC pulse compressors. New components to be design and manufactured

• New SC solenoid installed in the klystron • Tests ongoing for solenoid validation • BOC sent back to PSI. Thanks! • Klystron to be sent to INFN Xbox 3 • New signal generation, LLRF and acquisition system • Repaired klystron conditioned to 80 KV • Waiting for oil filtering machine to finish conditioning • Commissioning of new system ongoing Xbox 2 Xbox 1 SHORT SUMMARY ON XBOXES • Running one-cell experiment on T 24 • Now at 120 MV/m with 100 ns long pulse • Will continue after the Xmas shutdown • ½ arrived in Melbourne

MERRY XMAS! THANKS TO: A. MAGAZINIK, S. SAUZA BEDOLLA, P. MORALES SANCHEZ, S. LEBET, S. GONZALEZ ANTON, H. BURSALI, R. WOLF, Y. CUVET