Status of Mu2e Solenoids Michael Lamm for the Mu2e Project Working Group Meeting March 17, 2010 Organization Technical Progress Cost and Schedule

2 Mu2e Goals Measure the Rare Process:  - + N  e- + N relative to  - + N(A,Z)  + N(A, X) –Goal: 4 orders of magnitude increase in sensitivity over previous experiments How to do it: –Create a beam of high intensity, low momentum “in time” muons –Stop muons in aluminum target: form muonic atom –Turn experiment off for 700 nS to suppress “in time” background –Precisely measure mono-energetic electrons emitted from muon recoil from an Aluminum stopping target Magnets role in Mu2e –Focus, momentum select and transport of  - from primary target –Gradient field in transport to prevent out of time other particles from reaching stopping target –Provide a uniform stable field for the final captured electron spectrometer  105 MeV e -

March 17, 2010 Working Group Meeting 3 Solenoid System Production Solenoid 8 GeV P Transport Solenoid Graded field to collect conv. e - (2T  1T) Uniform field for e - Spectrometer (1T) e - Spectrometer ST PT CC 8 GeV P hit target. Reflect and focus  /  ’s into muon transport Strong Axial Gradient Solenoid Field 5T  2.5T Sign/momentum Selection Negative Axial Gradient in S.S. to suppress trapped particles ~0.2 T/m Detector Solenoid

March 17, 2010 Working Group Meeting 4 Magnet Procurement Strategy Fermilab will act as a “General Contractor”: PS and DS will likely be built in industry –Need to develop a strong conceptual design and technical specifications for vendors –Final engineering design done by industry –Similar strategy for most detector solenoids TS will likely be designed/built “in house” –Cryostat, mechanical supports built by outside vendors –Coils wound in-house or industry depending on technology choice –Final assemble and test at Fermilab Solenoid task has responsibility for all interfaces –Significant magnet coupling between PS-TS and TS-DS –Tight mechanical interfaces –Cryoplant, power supplies, instrumentation…

March 17, 2010 Working Group Meeting 5 Mu2e Functional and Interface Specifications for Solenoid Sub-system PS Building/ Mechanical CryoplantPoweringQuench Prot./Instr. Vacuum Absorber Target Collimator Beam Dump Stopping Target Tracker and Calorimeter DS Feedbox TSn Denotes functional + interface spec responsibility Iron Shielding Proton Beamline Denotes interface spec co-responsibility Absorber

March 17, 2010 Working Group Meeting 6 WBS Structure Where we are now Fabrication Phase Install and Commission

March 17, 2010 Working Group Meeting 7 Conceptual Design WBS Org Chart Most of team is in place Production Solenoid  Vadim Kashikhin Nikolai Andreev Igor Novitski V. Pronskikh R. Rabehl Detector Solenoid  Ryuji Yamada Masayoshi Wake Bob Wands Group (PPD) Cryogenic System  Tom Nicol  Tom Peterson  Jeff Brandt Quench Protection  G. Ambrosio  M. Lamm Power System  Sandor Feher  Walt Jaskierney (PPD) Transport Solenoid  Giorgio Ambrosio Nikolai Andreev Dan Evbota Mau Lopes Conceptual Design  Michael Lamm (L2)  Tom Page (L2 Project Engineer) Mechanical Design Oversight Vadim Kashikhin Magnetic Design Oversight Nikolai Andreev Integration Rodger Bossert Cryoplant Design  Jay Theilacker Group (AD) Tooling Concepts (Tom Page) Installation Concepts (Tom Page) Present Level of Effort Engineering 5.0 FTE Designers 1.5 FTE Proj. Management 0.75 Off project Scientists 2.0 Significant input and collaboration from outside of Solenoid Task: Rick Coleman Peter Limon Jim Miller Jim Popp Project Management…

March 17, 2010 Working Group Meeting 8 Engineering Challenges PS/TS/DS: three separate magnet designs but….. Coupled together magnetically –Really ONE Big Magnet Significant Forces (~100 Tons on end of DS from TS) Tight physical tolerances –Cold vs. Warm, with field excitation –Particularly with odd shaped TS Integration issues –It is our job to makes sure magnets built from different vendors, fit together, produce the required magnetic field

March 17, 2010 Working Group Meeting 9 MECO (BNL) vs. Mu2e Magnet Concept Copper Bar SSC cable

March 17, 2010 Working Group Meeting 10 Production Solenoid Challenges Large Volume : Aperture (1.8 m), Length ~5 m High field (5.6 T on NbTi) Large Amount of Stored energy (100 MJ) Asymmetric forces on ends (unlike HEP detector solenoids) 8 GeV Target in aperture produces 50 kW of power. Absorbers will intercept most beam energy however Could be 100 W energy distributed into coils Challenge for cooling Possibility of radiation damage to insulation and conductor Field profile well matched to requirements

March 17, 2010 Working Group Meeting 11 Progress on Several Fronts on PS Design Simplified Coil Geometry (3 uniform wound solenoid coils using same conductor x section) yet meets field longitudinal gradient requirements Superconductor cross section specified Conceptual Design of Mechanical Structure for radial support (hoop stress) Winding, bussing and splice scenarios considered Preliminary Radiation studies completed Insulation and structural damage Conductor stabilizer degradation from atomic defects Initial proposal for cooling scheme Quench protection studies to size aluminum stabilizer PS Coil Profile with iron Yoke

Design Concepts for PS Preload shell Outer support tube Pure Al layers (RRR>3000) 0.5mm fiberglass around cable 0.25mm fiberglass at each side of Al layer 0.5mm fiberglass at support tube 12 Vadim Kashikhin 23.9 MN 10.4 MN 10.9 MN N. Mokhov V. Pronskikh Neutron Flux Density Mechanical Analysis Structural Support Model Magnetic Model Coil and Insulation

13 Detector Solenoid 2 Tesla 2.5 m Aperture 5 meters long Atlas Solenoid Large Volume : Aperture (2 m), Length 11 m Upstream: Axially graded field (2T  1T) Downstream: Uniform 0.1% 1 T field (similar to ATLAS) Large Amount of Stored energy (35 MJ) Large asymmetric axial forces (unlike HEP detector solenoids) Design Status Two concepts for Coil Geometry Considered (which meet specs) Started mechanical FEA analysis of coils (Wands) Developing 3-D Solid Model to study interface issues Cryostat supports will likely be modeled after PS Solid Model DS End View

5-Segment DS Coil Design March 17, 2010 Working Group Meeting 14 Iron yoke shapes the end field + is part of Cosmic Ray Veto Field Profile Conductor Profile Wake/Yamada

March 17, 2010 Working Group Meeting 15 Transport Solenoid Design from Meco Meco Design has 60 solenoid rings Divided into two cryostats Gap in middle for P-bar and Vacuum Window There is a collimator for momentum selection in center region that cannot be adjusted In order to get desired field each coils has a unique amp-turns. Gap greatly complicates coil designs

March 17, 2010 Working Group Meeting 16 Mu2e Ideas Build center straight section as one removable piece Eliminates gap in center of SS Collimator should be rotatable to allow passage of  + for calibration (with minimal impact on magnets) Can Toroid sections be built in simpler units? Design Status Very preliminary concept of SS design which meets “negative gradient” spec. Alignment tolerance study completed (Lopes) Feasibility study of toroid section fabrication started

March 17, 2010 Working Group Meeting 17 Coil Design Progress Toroid Coil ConceptSS Coil Profile

March 17, 2010 Working Group Meeting 18 Cryogenic Design Cryogenic Distribution Boxes Function: Supply liquid Helium from cryoplant to magnet Room Temperature to Liquid Helium Power lead transition (power leads) Other activities: Magnet cryostat design Thermal model for magnet cooling Estimate heat loads and liquid helium req. for operation and RT  LHe cooldown

March 17, 2010 Working Group Meeting 19 Cost Estimate We are still working on the conceptual design so cost estimation is not yet possible. As system components reach a mature conceptual design, the fabrication WBS levels will be filled in. Estimating schedule and resources / task will depend on the specific activity. Possible sources for “basis of estimates” Our own experience with magnet fabrication Much of the APUL and CERN IR quad experience is relevant MECO WBS and Cost workbook, where applicable We may hire consultants for specific processes RFI may shed some light on fabrication process

March 17, 2010 Working Group Meeting 20 Long/Short Term Schedule Project EventDurationCompletion Bid process for final design 6 months0.5 years final design at industry12 months1.5 years design reviews.. Approve. To proceed6 months2.0 years Final assembly drawings9 months2.25 years design and build tooling, order conductor12 months3 years Build the coils (PS and DS)18 months4.5 years Put into cryostat.. Test in cryostat3 months5 years Ship to FNAL, Acceptance Tests3 months5.25 years in place in mu2e hall3 months5.5 years Install6 months6 years commissioning tests6 months6.5 years Preliminary CD/Start RFIJuly 2010 Internal Reviews of CDFall 2010 CDR CompleteJan 2011 First Pass at Long Term Schedule Relative to CD1 Approval

March 17, 2010 Working Group Meeting 21 Conclusion Mu2e is an important “Intensity Frontier” experiment for this decade at Fermilab –Fits well into lab program –Complements LHC program Substantial progress on solenoid conceptual design –Design team is largely in place –Short term goal is to complete CD by mid FY 2011 –Detailed cost and schedule to follow –Solenoids likely to be on critical path throughout project