325 MHz Spoke Cavity Prototype Cryomodule Project X Front-end Meeting Bob Webber November 3, 2010

Spoke Cryomodule Design Options: –Wait for full requirements specification –Proceed with cryo/mechanical design of spoke cavity cryomodule based on ‘best-guess’ (incomplete) requirements specifications up to the point of ‘decision to fabricate’ Option #1 has been followed during the past year Cryomodule Design Plan Up to This Time Page 2 Project X Front-end Meeting 11/3/10 – Bob Webber

Considerable effort of a strong team has gone into conceptual design of a spoke cavity cryostat based on: –800 mm cell length –SSR1 cavities operating CW at 2K –Current prototype cavity tuner design –SSR1 solenoids with integral x and y steering coils –New magnet power lead design –Inclusion of no beam instrumentation components By the end of the year, this conceptual work will be complete and the effort will be re-directed –To producing fabrication drawings, if this is the type of prototype cryomodule we decide to build –To SSR0 cryomodule conceptual design, if design inputs are provided –To completely different work, if next cryomodule tasks are not defined Present Situation Page 3 Project X Front-end Meeting 11/3/10 – Bob Webber

Tom Nicol Slides Begin Page 4 Project X Front-end Meeting 11/3/10 – Bob Webber

Tom Nicol - September 2, Cavity Cryomodule Assembly (conceptual design version) Current thinking is to develop an n-cavity cryomodule (n probably 3) with n+1 solenoids.

Tom Nicol - September 2, Cavity Cryomodule Assembly (conceptual design version)

Tom Nicol - September 2, Cavity Cryomodule Assembly (conceptual design version)

Tom Nicol - September 2, Moving forward from the conceptual design… Design tasks are being handled by a D/D design team led by Frank McConologue Incorporation of features to allow 2 K, CW operation – Large diameter pumping line – Add heat exchanger to each cryomodule – Large check valve (relief line) – Conduction cooled current leads similar to DESY and CERN designs, but at higher current Consolidate vacuum vessel access into one central region Build in solenoid adjustment mechanisms consistent with “few 10s of micron” positioning Compact the overall design to facilitate cavity-to-cavity spacing requirements between modules Revise existing input coupler design (if necessary) to handle higher heat loads during CW operation

Tom Nicol - September 2, Cavity Cryomodule Assembly Current leads Heat exchanger Check valve Input couplers Control valves and bayonets

Tom Nicol - September 2, Cavity Cryomodule Assembly Vacuum vessel, magnetic and thermal shields removed

Tom Nicol - September 2, Cavity Cryomodule Assembly Vacuum vessel ends removed

Tom Nicol - September 2, Cavity Cryomodule Assembly Close-up of solenoid with magnetic shield, c/w transition, adjustment pedestal Solenoid and shield C/W transition

Tom Nicol - September 2, Cavity Cryomodule Assembly Current lead assembly Solenoid pedestal

Tom Nicol - September 2, Conduction Cooled Current Lead Assembly 4 leads at 50 A, 2 leads at 200 A Thermal intercepts at 80 K and 5 K

Tom Nicol - September 2, Status Solid model continues to be refined Strongback design is nearly complete Support post design has been adapted from HINS counterpart Solenoid adjustment pedestal prototype design released Conduction cooled current lead design thermal analysis is nearly complete. Next step is to fabricate test sections to evaluate the effectiveness of thermal intercepts, potting procedure, insulation system, etc. Vacuum vessel design is in-process Thermal and magnetic shield designs are in-process Piping details need work, especially interface to pumping line, incorporation of check valve and heat exchanger

Tom Nicol Slides End Page 16 Project X Front-end Meeting 11/3/10 – Bob Webber

Tom Nicol/Tom Peterson 9/8/2010 PX Collab Meeting and 9/30/2010 TD PX/HINS Meeting Slides Begin Page 17 Project X Front-end Meeting 11/3/10 – Bob Webber

Conclusions up front Segmentation of the project X strings will probably be finer than the concepts which have been put forward so far due to –Liquid management with large specific heat loads –Steady state vapor velocities generated by high heat loads –4.5 K to 2 K heat exchanger sizing –Emergency venting with loss of vacuum Top-loading “bathtube” style vacuum vessel, while appropriate for the tall, thin 1/2-wave and 1/4-wave cavities, provides no advantages for our round SSR cryomodules. 650 MHz and 1.3 GHz cryomodule pipe sizes will be somewhat different from those envisioned for TESLA/ILC cryomodules due to the high CW heat loads and flow rates Project X CW Cryomodules, Tom Nicol, Tom Peterson 18

Cryomodule Pipe Sizing Criteria Heat transport from cavity to 2-phase pipe –1 Watt/sq.cm. is a conservative rule Two phase pipe size –5 meters/sec vapor “speed limit” over liquid –Not smaller than nozzle from helium vessel Gas return pipe (also serves as the support pipe) –Pressure drop < 10% of total pressure in normal operation –Support structure considerations Loss of vacuum venting P < cold MAWP at cavity –Path includes nozzle from helium vessel, 2-phase pipe, may include gas return pipe, and any external vent lines Project X CW Cryomodules, Tom Nicol, Tom Peterson 19

Segmentation Various degrees of possible segmentation –Total isolation and warm-up with adjacent cryomodule cold –Total separation of vacuum and cryogenic circuits but no provisions for maintaining segments cold which are adjacent to warm cryomodules Limits extent of control lengths and vacuum No end buffer from adjacent cold segment for vacuum let-up of warm segment. E.g., one must warm three segments to let up one. Segments downstream of warm one may not be held cold –Vacuum isolation and/or cryo circuit extent of various lengths, not all equal For example, liquid flow path shorter than thermal shield circuits Some valves distributed more finely than others. May have small “feed boxes” or valves in cryomodules for 2 K liquid supply. –Relief valve frequency -- low MAWP may force frequent vents Pipe sizes trade off with segmentation lengths Project X CW Cryomodules, Tom Nicol, Tom Peterson 20

325 MHz SSR assumptions 2.0 K helium cooling (~30 mbar) 3.2 W/cavity total heat (includes magnet heat) Includes one-time safety factor = 1.5 on heat/flow –So 3.2 W per cavity in analysis Cavity (cavity-solenoid) slot length = 0.8 m –For calculating pipe lengths as function of number of cavities Cavity cold MAWP = 2.5 bar Cavity surface area = 10,086 cm2 Single vapor/2-phase pipe Project X CW Cryomodules, Tom Nicol, Tom Peterson 21

Cryomodule segmentation, 325 MHz  2 CM of SSR1, Minimize of the inter-cryostate drift space  4 CM of SSR2, Provide drift space by missing cavity  1 CM of SSR0, 18 – 26 cavities L CM = m L CM =7.2m L CM =9.6 m From Nikolay Solyak Project-X, CW Linac (ICD-2+) Lattice Design, 16 Mar 2010 ! Have not studied implications, but “gut feeling” is “no way” Vent pipes every cavities, 40+ mm thermal contraction, assembly

325 MHz SSR cooling scheme

325 MHz steady-state results Number of cavities in a segment versus 2-phase pipe size 24 Small 2-phase pipe OK for steady-state SSR1 Cryomodules Tom Peterson

Air inflow heat flux limit Atmospheric air flowing into a vacuum via a round hole –~23 grams/sec per cm2 hole size Heat deposition by air condensing on cold surface –~470 J/g, so 10.8 kW per cm2 hole size Helium heat input per gram ejected for typical ( bar) pressures –~13 J/g Helium mass flow per air inlet area –~830 grams/sec helium per cm2 hole size Project X CW Cryomodules, Tom Nicol, Tom Peterson 25

For a 3-inch (76 mm) diameter opening, air flow becomes the limiting factor in heat deposition after a few cryomodules 26 3-inch port SSR1 Cryomodules Tom Peterson

325 MHz loss of vacuum venting 27 Just a note from our design effort. We would like for mechanical space reasons to use a 5-inch OD tube in our 325 MHz CM. The practical limit then is 8 cavities in series for emergency venting flow. SSR1 Cryomodules Tom Peterson

325 MHz 2-phase pipe conclusion Steady-state flow requirement is relatively low –4 cm ID is adequate to keep a low helium vapor velocity (< 5 m/sec) with over 20 cavities in series, such as one long SSR0 cryomodule (neglecting cross-section occupied by liquid, so we have to add to the diameter for a liquid level) Venting for loss of cavity vacuum determines 2-phase pipe size –A 3 inch air inlet hole implies roughly a 14 cm 2-phase pipe and a 19 cm vent line –Basically inch and 8 inch diameter, respectively Prototype SSR1 incorporates these pipe sizes even though they would not be required for this small cryomodule alone. 28 SSR1 Cryomodules Tom Peterson

325 MHz prototype

Conclusions This is just a first, quick look. Work is in progress. CW cryomodule piping requirements may be quite different from TESLA/ILC –325 MHz cryomodule 2-phase pipe sizes are overwhelmingly determined by venting requirements –650 MHz and 1.3 GHz CW liquid management lengths may be only one or a few cryomodules Thermal shield piping sizes may be like TTF Division of 325 MHz cryomodules into shorter sections for emergency venting looks necessary Division of CW 650 MHz and 1.3 GHz cryomodules into short strings for liquid management may be necessary 30 SSR1 Cryomodules Tom Peterson

Nicol/Peterson PX Collab Mtg Slides End Page 31 Project X Front-end Meeting 11/3/10 – Bob Webber

I believe serious questions remain as to the feasibility of a SSR0 section design that meets both beam dynamics and mechanical requirements –Minimum achievable cell length –Mechanically required vs. beam dynamics allowed segmentation –Exacerbated by lack of information on acceptable tuner and beam instrumentation designs Independent of above concern, a full set of functional requirements for a prototype cryomodule is not yet specified –I feel some responsibility to write “functional requirements specification” –I need help defining those requirements Disconnects Page 32 Project X Front-end Meeting 11/3/10 – Bob Webber

How do we proceed to address the SSR0 dilemma? Do we proceed with SSR1 cryomodule design work independently of resolving SSR0 issues? What is proper allocation of resources between: –Resolving SSR0 section dilemma –Proceeding with prototype SSR1 cryomodule design to answer questions important for SSR1 and 2 sections in any case What is practical, useful schedule for beam/cryomodule test? Is beam test of prototype SSR1 cryomodule useful? Can/should we afford people, time, and money to build separate prototype modules for mechanical and alignment purposes and for beam test purposes? Questions Toward a Plan Page 33 Project X Front-end Meeting 11/3/10 – Bob Webber

END Page 34 Project X Front-end Meeting 11/3/10 – Bob Webber

MDB Test Facility Layout Page MHz Spoke Cavity Test Facility 1.3 GHz HTS MDB Linac enclosure for 10 MEV Source of cryogenics Ion Source and RFQ Scale: Square blocks are 3ft x 3ft 650 CW RF HTS CW RF 325 CAGE Project X Front-end Meeting 11/3/10 – Bob Webber

Beam line shielding enclosure construction is complete Relay rack installation is in progress Proton ion source is operational and beam tests are in progress RFQ is ready for re-installation Shielding Assessment and Safety Assessment Document are complete and were submitted to AD ES&H on October 18,2010 MDB 10 MeV Beam Facility - Current Status Page 36 Project X Front-end Meeting 11/3/10 – Bob Webber

Beam Line Shielding Enclosure Project X Front-end Meeting 11/3/10 – Bob Webber Page 37 Fall 2009 Summer 2010 Shielding construction is now complete

Complete construction of beam line radiation shielding enclosure in MDB Obtain final operational approvals for the MDB Linac –Submit and review the Radiation Shielding Assessment –Submit and review the Safety Assessment Document Re-establish 2.5 MeV beam from RFQ Quantify parameters of 2.5 MeV beam from RFQ Configure the beam line for the “Six-Cavity Test” to verify high power RF vector modulator performance with beam in preparation for Project X beam chopper tests Replace existing proton ion source with an H- ion source Begin pursuit of the Project X beam chopper test –Finalize beam line design –Specify needed components –Begin initial component procurement – as FY11 budget permits FY11 MDB PX Beam Facility Scope of Work Page 38 Project X Front-end Meeting 11/3/10 – Bob Webber

SSR Cavity Status Page 39 Project X Front-end Meeting 11/3/10 – Bob Webber First Jacketed SSR1 in Cavity Test Cryostat

SSR1-01 Performance in MDB Test Facility Project X Front-end Meeting 11/3/10 – Bob Webber Spoke Cavity Accelerating Gradient - MV/meter Cavity Q 0 HINS Design Goal – 5E8 at 10 MV/m at 4°K Page 40

Few iterations in concepts of cavity / solenoid designs to minimize period (690  605 mm) In lattice was used: L p =610 mm Mechanical design: minimizing of df/dP RF coupler & tuner design is in progress Preliminary SSR0 Design Project X Front-end Meeting 11/3/10 – Bob Webber Page 41

Finalize wide-band chopper design to the point of specifying buncher cavities and focusing elements so that procurement might begin Establish and document functional requirements specification for the N-cavity prototype spoke cavity cryostat –Prototype is expected to serve as mechanical prototype as well as functioning beam line cryomodule to demonstrate chopped, Project X beam accelerated beam through SSR cavities Mechanical design presently assumes 3 cavities and 3 solenoids and includes no beam diagnostics Conceptual beam test assumes 4 cavities and 4 or 5 solenoids –Determine whether to use SSR0 or SSR1 cavities in this cryostat Must converge on integrated and realizable beam physics/mechanical design (i.e. cell spacing) for SSR0 section SSR0 cavities schedule? Currently iterating RF and mechanical cavity design Present SSR1 based mechanical design nearing critical decision time Tasks to Achieve Future Goals Page 42 Project X Front-end Meeting 11/3/10 – Bob Webber

Conclusion We have a front-end beam facility nearing completion of infrastructure construction (except cryogenics delivery system) We have a plan and defined objectives for the MDB Six-Cavity Test Subsequent stages of MDB Linac beam line will be directly in support of Project X and thus both depend on and will provide bases for Project X configuration decisions Page 43 Project X Front-end Meeting 11/3/10 – Bob Webber