WP 9.2 DDS Status, R.M. Jones, 25 th Oct 2010, WebEx Phone-in, Geneva 1 WP 9.2: DDS Status Roger M. Jones Cockcroft Institute and The University of Manchester WP 9.2 DDS Status, R.M. Jones, 25 th Oct 2010, WebEx Phone-in, Geneva 192 cells 8-fold interleaving 24 cells No interleaving 192 cells 8-fold interleaving Manifold Coupling slot Dipole mode Manifold mode fmin = 65 MHz tmax =15.38 ns s = 4.61 m fmin = 8.12 MHz tmax =123 ns s = m f=3.6 =2.3 GHz f/fc=13.75% Summary of CLIC_DDS_C Meets design Criterion? WP 9.2 DDS Status, R.M. Jones, 25 th Oct 2010, WebEx Phone-in, Geneva Circular Square =-8.28 =-4.14 =-2.07 Convex ellipticity Concave ellipticity Single undamped cell Iris radius=4.0 mm CLIC_DDS_E Elliptical Design E Fields WP 9.2 DDS Status, R.M. Jones, 25 th Oct 2010, WebEx Phone-in, Geneva CircularRectangularElliptical (Convex) Elliptical (Concave) of cavity 1 f acc (GHz) Eacc(V/m) H sur max /Eacc (mA/V) E sur max /E acc Iris radius = 4. 0 mm Iris thickness = 4.0 mm CLIC_DDS_E Elliptical Design, Single Undamped Cell Dependence of Fields on Chosen design WP 9.2 DDS Status, R.M. Jones, 25 th Oct 2010, WebEx Phone-in, Geneva 24 cells No interleaving 24 cells No interleaving Undamped Damped Q avg ~1700 CLIC_DDS_A Wake Wake of a non-interleaved 24 cell structure first structure of 8-fold interleaved structure chosen. Motivated by high gradient testing Wake is measurable and provides a useful comparison to simulations (but will not, of course, meet beam dynamics criteria) WP 9.2 DDS Status, R.M. Jones, 25 th Oct 2010, WebEx Phone-in, Geneva Matching CLIC_DDS_A Firstly, match-out either end of structure with regular cells: Structure for test will utilise a mode launcher Initially, simulate a structure with one regular cell and two matching cells at either end and we study the minima in S 11 as a function of the geometrical parameters of the matching cells (a, L adopt L variation, rather than b, from space considerations) Add additional (2, then 3) identical standard cells (const. imp) and follow the same procedure and modify parameters of matching cells to minimise S 11 The matching condition (on a, L) is that which coincident with all 3 simulations. Secondly, once complete, match-out the full, tapered structure based on this match. I/P WP 9.2 DDS Status, R.M. Jones, 25 th Oct 2010, WebEx Phone-in, Geneva Beam Port11 Port 2 E-field CLIC_DDS_A Match-out the full, tapered structure E-field and S 11 shown ~198.6mm Matching cell Surface E-Field Axial E-Field 5.0 A. DElia 7.5 E s (V/m x10 4 ) E z (V/m x10 4 ) z (mm) z (mm) 0 225 WP 9.2 DDS Status, R.M. Jones, 25 th Oct 2010, WebEx Phone-in, Geneva CLIC_DDS_A Eng. Design WP 9.2 DDS Status, R.M. Jones, 25 th Oct 2010, WebEx Phone-in, Geneva Water pipes for cooling Vacuum flange Power input Power output Tuning holes Cutaway-view Bea m V.Soldatov Mechanical Eng. Design of DDS_A WP 9.2 DDS Status, R.M. Jones, 25 th Oct 2010, WebEx Phone-in, Geneva DDSA, Reverse Side View CLIC_DDS_A Prototype Disks DSA, Front View VDL Fabricated. G. Riddone, Oct 15 th 2010!. 8mm WP 9.2 DDS Status, R.M. Jones, 25 th Oct 2010, WebEx Phone-in, Geneva Shape accuracy 5 m 1.7 m achieved Roughness Ra Iris region achieved Ra Shape accuracy 5 m 1.7 m achieved Roughness Ra Iris region achieved Ra Low-force probe: some disks show measuring indents (20 nm depth) after probing on the CMM Local hardness of the material is not constant. Cell Qualification of CLIC_DDS_A VDL (NL) have machined and measured several cells end cells. New!(recvd by CERN Oct 2010) Global profiles made with Zeiss CMM, free state measurement are illustrated for disk 24 Design, tolerance bounds and achieved profile shown ETA of all cells December 2010 Bonding of complete structure by 1 st quarter of 2011. WP 9.2 DDS Status, R.M. Jones, 25 th Oct 2010, WebEx Phone-in, Geneva I/P at /2 =15.9GHz Work in Progress/R&D Opportunities CLIC_DDS_A is equipped with mode launchers CLIC_DDS_B includes full HOM ports Initial studies on matching the HOM coupler for CLIC_DDS_B in progress (dipole band ~ 15.9 GHz 18 GHz) Sic Moving to a high phase advance (HPA) structure allows other parameters to be optimised 5 /6 phase advance structure design in progress (for initial design see Linac2010) In the HPA design further features being explored Additional manifold (8) Influence of SiC rods on overall Q EnhancedC oupling Standard DDS Manifold Additional Manifold WP 9.2 DDS Status, R.M. Jones, 25 th Oct 2010, WebEx Phone-in, Geneva Status CLIC_DDS_A : RF (inc. mode launcher) and mechanical design has been completed. Qualifications cells fabricated Oct 2010! (VDL, NL)all cells expected Dec 2010 Structure will be subsequently bonded in the first quarter of ready for high power testing in 2011 at the CLIC test stand. Status CLIC_DDS_B: Equipped with HOM couplers design underway New CLIC_DDS R&D in progress: HPA : High phase advance (5 /6) design is being studied. Allows optimisation of remaining parameters minimise surface fields, wakefields at stipulated v g, maximise luminosity and efficiency Novel enhancements to wakefield optimisation with a view to optimising efficiency and increasing luminosity additional manifolds, SiC rods. Submitted joint (CERN et al) proposal to participate in FACET wakefield tests (important to verify DDS wakefield simulations) More details here:&resId=1&materialId=slides&confId=4507 Final Remarks