Summary of the RF Parallel Session Steve Virostek Lawrence Berkeley National Lab MICE Collaboration Meeting 18 June 16, 2007

Summary of the RF Parallel Session Talks from MICE CM18 Page 2Steve Virostek - Lawrence Berkeley National Lab RF Session Talks MuCool RF Program: RF Cavity R & D (A. Bross) RFCC Module Design Update (S. Virostek) Coupling Coil Integration with the RFCC Module (S. Virostek)

MuCool RF Program: RF Cavity R & D 805 and 201 MHz Studies ANL / FNAL / IIT / LBNL U Miss / Cockcroft Alan Bross MICE Collaboration Meeting 18 June 13, 2007

Summary of the RF Parallel Session Talks from MICE CM18 Page 4Steve Virostek - Lawrence Berkeley National Lab MuCool Test Area

Summary of the RF Parallel Session Talks from MICE CM18 Page 5Steve Virostek - Lawrence Berkeley National Lab MuCool Test Area Facility to test all components of cooling channel (not a test of ionization cooling) –At high beam power Designed to accommodate full Linac Beam 1.6 X Hz – 2.4 X p/s –  600 W into 35 cm LH MeV –RF power from Linac (201 and 805 MHz test stands) Waveguides pipe power to MTA

Summary of the RF Parallel Session Talks from MICE CM18 Page 6Steve Virostek - Lawrence Berkeley National Lab MTA Hall

Summary of the RF Parallel Session Talks from MICE CM18 Page 7Steve Virostek - Lawrence Berkeley National Lab 805 MHz Data seem to follow universal curve –Max stable gradient degrades quickly with B field Remeasured –Same results –Does not condition Gradient in MV/m Peak Magnetic Field in T at the Window

Summary of the RF Parallel Session Talks from MICE CM18 Page 8Steve Virostek - Lawrence Berkeley National Lab 805 MHz Imaging

Summary of the RF Parallel Session Talks from MICE CM18 Page 9Steve Virostek - Lawrence Berkeley National Lab 805 MHz Sparking Damage Curved Be Window after Processing in Magnet Field Small amount of sparking damage on upstream window at 12 o’clock (least damage seen in Studies). Cavity bright & clean. Damage on copper iris is mainly from previous testing.

Summary of the RF Parallel Session Talks from MICE CM18 Page 10Steve Virostek - Lawrence Berkeley National Lab Next 805 MHz study - Buttons Button test –Evaluate various materials and coatings –Quick change over Field Profile

Summary of the RF Parallel Session Talks from MICE CM18 Page 11Steve Virostek - Lawrence Berkeley National Lab First Set of Button Data – TiN Coated Cu

Summary of the RF Parallel Session Talks from MICE CM18 Page 12Steve Virostek - Lawrence Berkeley National Lab TiN Coated Cu – After Running

Summary of the RF Parallel Session Talks from MICE CM18 Page 13Steve Virostek - Lawrence Berkeley National Lab RF R&D – 201 MHz Cavity Design The 201 MHz Cavity is now operating –New x-ray background data collected (see Alan’s talk)

Summary of the RF Parallel Session Talks from MICE CM18 Page 14Steve Virostek - Lawrence Berkeley National Lab 201 MHz Cavity Status The flat Cu windows have been replaced w/curved Be windows Slower conditioning and more sparking than with the Cu. May be due to better clean room at J-Lab during initial installation. –However, MTA CR air quality was measured at class 100 or better So far the 201 w/Be windows has been conditioned to ~5MV/m No running for >3 weeks due to 201 power source problems –Note: The cavity is now out of tune (beyond the range of power source) and must be re-tuned via the jacking screws –Cavity frequency dropped ~400 kHz w/curved Be windows installed –Will get from LBNL to do the tuning

Summary of the RF Parallel Session Talks from MICE CM18 Page 15Steve Virostek - Lawrence Berkeley National Lab Clean Room for 201MHz Cavity

Summary of the RF Parallel Session Talks from MICE CM18 Page 16Steve Virostek - Lawrence Berkeley National Lab 201 MHz Sparking Damage on Flat Copper Window coated with TiN over center portion The inside of the cavity appeared bright & clean Very little spark damage after RF processing to 18 MV/m One copper splatter visible (photo)

Summary of the RF Parallel Session Talks from MICE CM18 Page 17Steve Virostek - Lawrence Berkeley National Lab Curved Be window Installation Tyvek-wrapped Mike Dickinson and Ben Ogert installing one of the Be windows

Summary of the RF Parallel Session Talks from MICE CM18 Page 18Steve Virostek - Lawrence Berkeley National Lab Plans for the MTA Continue 805 MHz button tests w/bare & TiN coated buttons We have buttons made with the following metals –Tantalum –Tungsten –Molybdenum-zirconium alloy –Niobium –Niobium-titanium alloy –Stainless steel Continue conditioning 201 with Be windows (if power ever becomes available) without B field (after re-tuning). –Then do B field scan Can go up to few hundred gauss at present Need new pumping system to go higher And eventually Coupling Coil

Summary of the RF Parallel Session Talks from MICE CM18 Page 19Steve Virostek - Lawrence Berkeley National Lab Coupling Coil Layout in the MTA

RFCC Module Design Update  automatic tuners  cavity suspension  cavity installation Steve Virostek Lawrence Berkeley National Lab MICE Collaboration Meeting 18 June 13, 2007

Summary of the RF Parallel Session Talks from MICE CM18 Page 21Steve Virostek - Lawrence Berkeley National Lab RF Cavity & Coupling Coil Modules in MICE RFCC Modules

Summary of the RF Parallel Session Talks from MICE CM18 Page 22Steve Virostek - Lawrence Berkeley National Lab Updated RFCC Module 3D CAD Model 201 MHz RF cavity Automatic tuners Cavity suspension

Summary of the RF Parallel Session Talks from MICE CM18 Page 23Steve Virostek - Lawrence Berkeley National Lab Cavity Tuner Design Features Six evenly spaced automatic tuners per cavity provide frequency adjustment Layout avoids interference with cavity ports Tuners touch cavity and apply loads only at the stiffener rings Tuners operate in “push” mode only (i.e. squeezing)

Summary of the RF Parallel Session Talks from MICE CM18 Page 24Steve Virostek - Lawrence Berkeley National Lab Four Cavity Layout in Vacuum Vessel Tuner layout rotated 30 cavity pairs Actuators are off cavity center plane to avoid coupling coil Bellows connections at vacuum vessel feedthroughs 0 to -460 kHz tuning range (0 to -4 mm) 1.6 MPa max. actuator pressure (  50 mm)

Summary of the RF Parallel Session Talks from MICE CM18 Page 25Steve Virostek - Lawrence Berkeley National Lab Cavity Tuner Section View Ball contact only Dual bellows feedthrough Tuner actuator (likely air) Pivot point Fixed (bolted) connection

Summary of the RF Parallel Session Talks from MICE CM18 Page 26Steve Virostek - Lawrence Berkeley National Lab Tuner component Details Fixed arm Pivoting arm Actuator & bellows assembly Forces are transmitted to the stiffener ring by means of “push/pull” loads applied to the tuner lever arms by the actuator assembly

Summary of the RF Parallel Session Talks from MICE CM18 Page 27Steve Virostek - Lawrence Berkeley National Lab Six strut system provides kinematic cavity support Orthogonal strut layout is stiff and allows accurate cavity positioning Kinematic mounts fix cavity without over- constraint Cavity Suspension System

Summary of the RF Parallel Session Talks from MICE CM18 Page 28Steve Virostek - Lawrence Berkeley National Lab Cavity Suspension System 1 vertical strut 2 horizontal struts 3 axial struts

Summary of the RF Parallel Session Talks from MICE CM18 Page 29Steve Virostek - Lawrence Berkeley National Lab Strut End Connection Details One end of the struts is attached to a fixed lug welded to the ID of the vacuum vessel The cavity end of the vertical and one of the horizontal struts are attached directly to the stiffener ring The cavity end of the axial and one of the horizontal struts are attached to the fixed leg of a tuner

Summary of the RF Parallel Session Talks from MICE CM18 Page 30Steve Virostek - Lawrence Berkeley National Lab Four Cavity Layout in Vacuum Vessel Dedicated struts (6) for each cavity No contact between cavity pairs Struts axially fix the outside walls of the cavity pairs Tuning deflections increase cavity gap

Summary of the RF Parallel Session Talks from MICE CM18 Page 31Steve Virostek - Lawrence Berkeley National Lab Cavity Installation Sequence Pre-assemble cavities with Be windows and tuners (w/o actuators) Slide inner cavities into vacuum vessel using spacer/alignment blocks Shim cavity to align tuner & coupler vacuum feedthrus with tuner mounts and cavity ports Install struts, tuner actuators and RF couplers Repeat same process for outer cavities

Coupling Coil Integration with the RFCC Module Steve Virostek Lawrence Berkeley National Lab MICE Collaboration Meeting 18 June 13, 2007

Summary of the RF Parallel Session Talks from MICE CM18 Page 33Steve Virostek - Lawrence Berkeley National Lab Coupling Coil Integration Topics New coupling coil design developed by LBNL & ICST (Harbin) Increased coil length (+35 mm to 285 mm) results in longer vacuum vessel Integration issues w/tuners and RF, vacuum & diagnostic cavity ports Must transmit magnetic forces from the cold mass supports to the vacuum vessel New 3D model developed by LBNL for integration

Summary of the RF Parallel Session Talks from MICE CM18 Page 34Steve Virostek - Lawrence Berkeley National Lab Reinforcing plates Indented sections Service tower Cryocoolers Support cone Cold mass supports Coil assembly He cooling pipes Coupling Coil Design Configuration

Coupling Coil Gusset Connections Gussets between cold mass support cones and vacuum shell transmit magnetic forces Tuner actuators nest between gussets

Summary of the RF Parallel Session Talks from MICE CM18 Page 36Steve Virostek - Lawrence Berkeley National Lab Upper Cold Mass Support Cones Weld

Summary of the RF Parallel Session Talks from MICE CM18 Page 37Steve Virostek - Lawrence Berkeley National Lab Connection to Support Side Plate Support stand side plate Weld Tuner cutout Interior gusset

Summary of the RF Parallel Session Talks from MICE CM18 Page 38Steve Virostek - Lawrence Berkeley National Lab Vacuum Vessel Assembly to Coil Vacuum weld on interior

Summary of the RF Parallel Session Talks from MICE CM18 Page 39Steve Virostek - Lawrence Berkeley National Lab RF Coupler/Coil Interface Coupler vacuum sleeve nests in coil vacuum shell recess (3 mm gap)

Summary of the RF Parallel Session Talks from MICE CM18 Page 40Steve Virostek - Lawrence Berkeley National Lab Vacuum System/Coil Interface Vacuum manifold Vacuum pump Gate valve

Summary of the RF Parallel Session Talks from MICE CM18 Page 41Steve Virostek - Lawrence Berkeley National Lab Vacuum System Integration Inside cavity vacuum connection Outside cavity vacuum connection Vacuum manifold Vacuum pump Gate valve

Summary of the RF Parallel Session Talks from MICE CM18 Page 42Steve Virostek - Lawrence Berkeley National Lab Vacuum Manifold/Coil Interface Vacuum manifold end nests in coil vacuum shell recess (3 mm gap)