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 σ =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 ε=-8.28 ε=-4.14 ε=-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. D’Elia 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 µm 1.7 µm achieved Roughness Ra Iris region achieved Ra Shape accuracy 5 µm 1.7 µm 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