1 / 32

SC Elliptical cavities design and associated R&D MAX mid-term design review

SC Elliptical cavities design and associated R&D MAX mid-term design review. 12/13 NOVEMBER 2012, SCK•CEN, Brussels R. Paparella , INFN Milano On behalf of the task 3.1 team. Layout of the talk. Elliptical cavities RF design from ASH/TRASCO collaboration

beth
Download Presentation

SC Elliptical cavities design and associated R&D MAX mid-term design review

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. SC Elliptical cavities design and associated R&D MAX mid-term design review 12/13 NOVEMBER 2012, SCK•CEN, Brussels R. Paparella, INFN Milano On behalf of the task 3.1 team

  2. Layout of the talk • Elliptical cavities • RF design from ASH/TRASCO collaboration • Cavity manufacturing and cold test • Helium tank integration, magnetic shielding and fast tuner • ADS cryomodule test stand • Cryostat thermal design • Manufacturing and assembly at SIMIC • Experimental results • Commissioning at IPNO • Review of performed cold tests • Current status and perspectives R. Paparella, MAX mid-term design review, Brussels, November 12-13, 2012.

  3. The b = 0.47 cavity – RF design • Cavity final design at 704.4 MHz has been the result of the TRASCO/ASH collaboration, exploiting a fully parameterized model of a SC cavity • Full parametric model of the cavity in terms of 7 meaningful geometrical parameters: • Ellipse ratio at the equator (R=B/A)Ruled byMechanics • Ellipse ratio at the iris (r=b/a)Epeak • Side wall inclination (a) and position (d)Epeak vs. Bpeak tradeoff and coupling k • Cavity iris radius RirisCoupling k • Cavity Length L b • Cavityradius Dused for frequency tuning • Behavior of all e.m. and mechanical properties has been found as a function of the above parameters R. Paparella, MAX mid-term design review, Brussels, November 12-13, 2012.

  4. The b = 0.47 cavity – figures R. Paparella, MAX mid-term design review, Brussels, November 12-13, 2012.

  5. The b = 0.47 cavity – prototypes • Two low and two high RRR single-cell prototypes built within TRASCO: • Built by E. Zanon (Italy) • Treated at CEA-Saclay and TJNAF with BCP, HPWR and class 100 CR assembly • Vertically tested at CEA-Saclay, TJNAF and LASA R. Paparella, MAX mid-term design review, Brussels, November 12-13, 2012.

  6. The b = 0.47 cavity – building the cavity • Dimensional and RF test on half-cells and on dumb-bells for QC • Soft-BCP to clean the welding region • Reduced number of welds, time-dominating factor is the pump down and the cooling after welding R. Paparella, MAX mid-term design review, Brussels, November 12-13, 2012.

  7. The b = 0.47 cavity – 5 cell cavity • Defined the production choosing all the technological solutions • NbTi Flanges based on TTF/SNS solution • Ready for Titanium Helium Vessel (with stiffening TIG welded) • Dummy HOM ports R. Paparella, MAX mid-term design review, Brussels, November 12-13, 2012.

  8. The b = 0.47 cavity – 5 cell cavity vert tests • Ep/Eacc=3.57 , Bp/Eacc=5.88 mT/(MV/m) • Z501 – TJNAF 31/03/2004 , Z502 – Saclay 24/06/2004 R. Paparella, MAX mid-term design review, Brussels, November 12-13, 2012.

  9. The b = 0.47 cavity – toward dressed cavity • A special setup has been built on purpose for cavity FF and goal frequency tuning • Helium tank realized to fulfill external stiffness requirements R. Paparella, MAX mid-term design review, Brussels, November 12-13, 2012.

  10. The b = 0.47 cavity – coaxial blade tuner • A coxial blade tuning system has been designed, inspired by the model realized by INFN for TESLA cavities. • A moving steel leverage transfers, through deforming Ti blades, the tuning action of stepper motor drive unit. • Two piezo actuators allow for fast and fine tuning R. Paparella, MAX mid-term design review, Brussels, November 12-13, 2012.

  11. The b = 0.47 cavity – magnetic shield • Both inner cryoperm shield in tank and outer m-metal shield in warm region solutions have been investigated • Finally internal designed has been fixed • Pre-assembled to measure the shielding and compare to simulations R. Paparella, MAX mid-term design review, Brussels, November 12-13, 2012.

  12. The ADS cryomodule test stand • Short, single-cavity module jointly realized by INFN Milano and IPN Orsay within the EUROTRANS project • Based on the SNS concept of short independentlyfed and rapidly exchangeable units • will be used for long testing for the reliability characterization of components R. Paparella, MAX mid-term design review, Brussels, November 12-13, 2012.

  13. The cryomodule – cavity frame • Cavity power coupler orientation is vertical • Reference for supports is CEBAF solution • Cavity space frame simplifies assembly and handling of the cavity after CR • No need for vertical movements • Kept minimal longitudinal space (flat heads vs standard PV dome heads) R. Paparella, MAX mid-term design review, Brussels, November 12-13, 2012.

  14. The cryomodule – cryogenics • Helium buffer in the module • Liquid helium line for coupler cooling • Valve box from IPN R. Paparella, MAX mid-term design review, Brussels, November 12-13, 2012.

  15. The cryomodule – manufacturing • Cryomodule has been manufctured by SIMIC firm at Camerana (Italy) • Delivery to IPNO in March 2010 R. Paparella, MAX mid-term design review, Brussels, November 12-13, 2012.

  16. The cryomodule – IPNO Experimental area • RF source • 160 kW DC PS • 80 kW IOT • Doorknob transitions • Power coupler • Cryogenics valve box • Cavity and tuning systems R. Paparella, MAX mid-term design review, Brussels, November 12-13, 2012.

  17. The cryomodule – commissioning at IPNO R. Paparella, MAX mid-term design review, Brussels, November 12-13, 2012.

  18. Results – RF power supply & conditioning • Coupler conditioning bench • Tunable cavity with copper plunger • Baking, vacuum management and diagnostics • As of today: • Couplers and cavity baked at 130°C → vacuum up to 5.10-8 mbar, no leak detected on the ceramic window • A first travelling wave (CW) conditioning at 1kW is done • Tests of RF circulator • Circulator efficiency is very sensitive to temperature & the regulation system of the coil is slow • Several Breakdowns / Flash occurred in the DC power supply (40 kV – 4 A) • 2 modules were sent to Bruker for assessment R. Paparella, MAX mid-term design review, Brussels, November 12-13, 2012.

  19. Results – RF power supply & conditioning E. Rampnoux & S. Berthelot Pre -conditioning (1 kW) of the couplers Cout Cin RF power (W) Time • Power ramped-up to 880 W in 24 h • Automatic procedure and control program validated. • Good signal transmission (reflection coeff.≈-30 dB) • No multipacting detected during the low power test • Vacuum leak rate remained at: 1.210-8 mbar.l.s-1 RF power (W) R. Paparella, MAX mid-term design review, Brussels, November 12-13, 2012.

  20. Results – RF power supply & conditioning High power supply & coupler status • DC power supply has been repaired and electric insulation improved. • 17th to 21st Spet.2012 : the IOT has been successfully re-re-re-tested with its RF circulator in full reflection until 80 kW. The current of the circulator coil had been tuned to enable fast RF power increase (switch on/off). (J. Lesrel (IPNO)) • The DC power supply can now be control through a labview program (C. Joly (IPNO)) • 25th sept. 2012 : The coupler test stand was assembled to the IOT • The preparation of the High power conditioning is almost achieved (cabling, safety box ….) • Conditioning will start in October 2012 E. Rampnoux R. Paparella, MAX mid-term design review, Brussels, November 12-13, 2012.

  21. Results – critical coupling cold tests • Critical coupling – no power coupler: • Understand the complete cryogenic system behavior • Q0 measurement @ 4K & 2K • Check the good behavior of the RF Phase Locked Loop (PLL) • Measurement of the static capabilities of the tuning system : stepper motor • Fast tuning systems influence : range of detuning & piezos Transfer Function • Overview of the tests campaign • 1st test : - July 2010 - Big leakage on the He tank detected. Experiment stopped & cavity travelled back to ZANON. • 2nd test : - February/March 2011 - New leakage on the He tank – test at 4 K but we encountered problems with the PLL : not able to power correctly the cavity. • 3rd test : - October 2011 – cavity characterization at 1.9 K. • 4th test: - May 2012 – cryogenic characterization of cryomodule and cryoplant. R. Paparella, MAX mid-term design review, Brussels, November 12-13, 2012.

  22. Results – 1st cold test R. Paparella, MAX mid-term design review, Brussels, November 12-13, 2012.

  23. Results – 1st cold test R. Paparella, MAX mid-term design review, Brussels, November 12-13, 2012.

  24. Results – 2nd cold test Experimental results ■ Measurement of the cryogenic procedure only at 4K (2K pumping system was not ready). ■ Supervision procedure and safety for cryo. & vacuum had been finalised. ■ Stepper motor tuning capabilities measured stepper motor - detuning range (@ 4K): ~270 kHz A. El Tarr (IPNO) Cryogenic control system by A. El Tarr (IPNO) Programmable logic controller (Siemens) : _ collect data (vacuum, temperature, level s) _ valves control _ manage safety aspects (Vacuum loss, Quench, etc…) Labview supervision programme : _ display the measured data _ manage the cool down procedure R. Paparella, MAX mid-term design review, Brussels, November 12-13, 2012.

  25. Results – 2nd cold test AFTER BEFORE adjustments ■ Improvements of the piping for cool-down procedure ■ A new leakage appeared on He tank. Repaired at IPNO (several N2 thermal cycles applied). OK ■Bringing material used for the welding : Ti Gr2 RF feedthrough replaced with INFN trick ! ■ Malfunctioning of the PLL system : no possibility to inject RF power at the right frequency, only a very low signal in the cavity. No Q0 measurement. → filter of the loop was modified (hardware). R. Paparella, MAX mid-term design review, Brussels, November 12-13, 2012.

  26. Results – 3rd cold test • No leak anymore on the tank → repairing procedure confirmed March 2011 October 2011 • Static losses : ~7.5 W (@ 2 K) (N. Chevalier) & ~ 5.5 W (@ 4 K - module closed on it self) • A Few points which still deserved to be improved • « warm » point detected at the Cryomodule /valve box connection • Level probes in the helium pot need to be gauged • 2K pumping achieved during one day and control by hand • No direct pressure on the helium bath, only an rough idea of the helium bath temperature. • Some thermal sensors were poorly “thermalized” R. Paparella, MAX mid-term design review, Brussels, November 12-13, 2012.

  27. Results – 3rd cold test Measurement at ~ 1.9 K (Rsurf ≈ 9 nΩ; RBCS≈ 3 nΩ → Rres~ 6 nΩ) Le 27/10/2011 afternoon (T~ 1,9K) Le 27/10/2011 morning (T~ 2.0 K) Processing multipacting Quench Coupling : _ Qi ≈ 2.0 1010 _ Qt ≈ 2.3 1011 the 12/10/2011 (T~ 4.2 K) RF cable limits (breakdown @ Pinc~ 170W) (@ βg=0.47) R. Paparella, MAX mid-term design review, Brussels, November 12-13, 2012.

  28. Results – 3rd cold test SEIZED !? • Motor • Hysteresis on small displacement (~0.1 mm) : 2kHz • After a few cycle motor action was blocked : Screw and nuts seized!! • Piezo actuators • Effect below expectation by one order of magnitude : +150V → ~200 Hz detuning. • Measurement only achieved at 4K, with a high sensibility to pressure variation. • Doubt on the cabling? R. Paparella, MAX mid-term design review, Brussels, November 12-13, 2012.

  29. Results – 4th cold test R. Paparella, MAX mid-term design review, Brussels, November 12-13, 2012.

  30. Results – 4th cold test • The module and the cryogenic installation are fully qualified & we set-up a system which enable to have an accurate control of the helium bath temperature. • Measured performances in agreement with expectations : at 1.9 K one can operate the module until ~35 W heat load on the cavity + ~ 6 W static losses (i.e. ~ 41 W Losses). (limitation seems to be due to the diameter size of valves) • Warm point at interconnection valves box / cryostat is still here : we probably have to live with it (static losses are quite low). • Instrumentation can always be improved : • Homemade level probes doesn’t work properly - New ones with electronic control box will be ordered to AMI (American Magnetics). • Investigation on thermal sensor shift in progress (maybe heat load from cables) R. Paparella, MAX mid-term design review, Brussels, November 12-13, 2012.

  31. Results – understanding motor seizing • No large failing has been detected, just clear evidences of high level of friction. The rather large quantity of copper stripped in one point could be the major responsible for the actual seizing. • Analysis of the story of motor unit revealed that CuBe shaft has not been heat-treated / hardened: big impact on material strength as well as surface hardness. • These drive units produced by INFN and used so far are going to be replaced by XFEL-compliant drive units that have been already purchased (delivery expected within October) within MAX funding. • These units will be the exact replica of XFEL ones, taking therefore full benefit of DESY expertise and quest for reliability. 1.5 mm Copper deposition on one steel nut thread surface R. Paparella, MAX mid-term design review, Brussels, November 12-13, 2012.

  32. Perspectives • Except few instrumentation (probe thermal sensor) details the module is fully operational on the cryogenic point of view. • We are currently moving the helium pumps (primary + roots) to its final configuration in a new building. Ready for January 2013. • The power coupler conditioning will start very soon and we plan a 2 months period for the test : October - November 2012 • A clean room session has to be foreseen for December 2012: for the power coupler assembly. • The Module preparation and wave guide installation is planned for: December 2012 / January 2013. • First High Power test : February / March 2013. MarouaneEl Yakoubiwill take in charge the 700 MHz experimental program at IPNO (Start mi-October 2012) R. Paparella, MAX mid-term design review, Brussels, November 12-13, 2012.

More Related