1. Mu2e Project Overview Mu2e WGM R. Ray 3/17/2010 13/17/2010 - Mu2e WGM

2. Mu2e Our primary scientific requirement is to: search for charged lepton flavor violation with unprecedented sensitivity. We will measure the ratio of the coherent neutrinoless conversion in the field of a nucleus of a negatively charged muon into an electron to the muon capture process: 3/17/2010 - Mu2e WGM2 with a sensitivity R  e < 6×10 -17 at 90% CL. This is almost a four order-of- magnitude improvement over the existing limit. The observation of such a process would be unambiguous evidence of physics beyond the Standard Model.

3. Overview of Mu2e 3 High Z target to maximize pion production Axially-graded field to maximize pion capture 5 T 2.5 T 2 T1 T Curved transport selects low energy   Muon stopping target in a 2 T axially graded field to improve conversion acceptance High rate e  detectors in constant 1 T field. Cosmic ray shield not shown 3/17/2010 - Mu2e WGM

4. Accelerator Mu2e uses Booster batches that are available when the Main Ring is ramping for the 120 GeV neutrino program.  Mu2e has no impact on NOvA. The Mu2e experiment needs bursts of protons delivered on target within a time window of ~200 ns every 1.7 s, corresponding to the revolution time of the Debuncher ring. The total number of protons to be delivered on target for the experiment is 4×10 20 per year.  The Collaboration prefers a high duty factor that minimizes instantaneous rates but has never been able to quantify that requirement. 4 To spread out transfers to the Accumulator Mu2e brings booster beam into the recycler, similar to NOvA, but kicks it out into the P1 line and into the pbar Accumulator. Accumulator beam is split into 4 smaller bunches and transferred, one at a time, into the Debuncher. Slow spill from Debuncher to experiment. and Recycler Mu2e 3/17/2010 - Mu2e WGM

5. Accelerator Scenario 5 Recycler 4 5 6 3 2 1 from Booster to Accumulator NOvA batch We thread beam in-and-out through the Recycler injection gap while NOvA beam is circulating. NOvA accepts 6 “batches” from Booster, then performs “slip stacking” to a slightly different energy (and hence different orbit) in order to accept 6 more later. 3/17/2010 - Mu2e WGM

6. Accelerator Scenario 6 Recycler 4 5 6 3 2 1 from Booster to Accumulator NOvA batch Mu2e batch 3/17/2010 - Mu2e WGM

7. Accelerator Scenario 7 Recycler 5 6 4 3 2 1 from Booster NOvA batch Mu2e batch to Accumulator 3/17/2010 - Mu2e WGM

8. Accelerator Scenario 8 Recycler 6 1 5 4 3 2 from Booster NOvA batch Mu2e batch to Accumulator 3/17/2010 - Mu2e WGM

9. Accelerator Scenario 9 Recycler 1 2 6 5 4 3 from Booster NOvA batch Mu2e batch to Accumulator 3/17/2010 - Mu2e WGM

10. Accelerator Scenario 10 Recycler 1 2 3 6 5 4 from Booster NOvA batch Mu2e batch to Accumulator 3/17/2010 - Mu2e WGM

11. Accelerator Scenario 11 Recycler 2 3 4 1 6 5 from Booster NOvA batch Mu2e batch to Accumulator After Mu2e batches have passed through, inject the last six batches for NOvA. 3/17/2010 - Mu2e WGM

12. Accelerator It is necessary to upgrade the Booster to operate at 15 Hz in order to operate any new experiments simultaneously with NOvA (MicroBooNe, g-2, Mu2e)  AD has been continuously upgrading the Booster over time. This is not part of the Mu2e Project, but we have to make sure that it happens. The Recycler has to be connected to the P1 line at MI-52 and an appropriate extraction kicker, identical to the NOvA injection kicker, must be fabricated and installed.  There is some question about whether the fall-time of the NOvA kicker is fast enough. Accumulator and Debuncher must be reconfigured.  Both require new 2.5 MHz RF systems. Bunches are formed in the accumulator and the have to be held in the Debuncher.  Accumulator also requires a 53 MHz system for momentum stacking.  Apertures in P1, P2, AP1, AP3 will have to be opened up to accommodate higher beam throughput.  A slow extraction scheme has to be designed and implemented in the Debuncher. 123/17/2010 - Mu2e WGM

13. External Beamline A new external beamline from the Debuncher to the Mu2e detector hall is required.  Civil construction  Electrostatic and magnetic septa, new bending and focusing elements, final focus system, optics, collimators, etc. 13 To eliminate prompt backgrounds we require minimal beam between pulses.  MECO spec was 10 -9 (ratio of beam between pulses to beam in pulses) but the requirement is time-dependent. Extra beam immediately after the pulse is OK, several hundred ns after pulse is trouble. Necessary to monitor the beam between pulses to know how we are doing. Two schemes exist but neither is very advanced. Need someone to take ownership. 3/17/2010 - Mu2e WGM Beamline

14. Target and Shield Production Target  Water-cooled gold target in titanium jacket  Large Z to max. pion production  Thin to minimize pion absorption  Preliminary thermal analysis complete. Safety factor of 4 Benchmark calculations with prototype Design review with target experts in the Fall 14 Production Target Heat Shield 25 kW proton beam 2.2 kW ave power in target Design power load 8.6 kW Heat Shield  76 ton water-cooled Cu and W heat and radiation shield to protect PS coils from nuclear heating, radiation damage and quenching.  ~16 kW of heat generated in shield  Detailed investigation of energy deposition underway (Mokov) Looking at other materials that may do a better job of absorbing neutrons. 3/17/2010 - Mu2e WGM

15. Accelerator Issues AD is very heavily committed. Getting resources will be a challenge. If g-2 is in the mix, we do not have a working plan  Both use the pbar source and recycler, but in different ways. Some overlap.  Would need a plan that allowed modifications to pbar source for each experiment and running time for g-2. Must be consistent with CD process or funded in a different way. Running the Tevatron for an additional 1-2 years does not impact Mu2e unless g-2 is in the mix. Shielding assessment is required for pbar source. Restricted occupancy likely to be required.  Active or passive? 3/17/2010 - Mu2e WGM15

16. Solenoids The solenoids impact everything else and drive our cost and schedule. We now have a significant team of people working on the solenoids including a subproject engineer and L3 managers (Great job my Mike Lamm in assembling a team). Mike Lamm will give you a solenoid update. 163/17/2010 - Mu2e WGM

17. Muon Channel Selects   and momentum range, stops   in thin target foils, and absorbs some secondaries Components include:  Vacuum system  Collimators  Stopping target & monitor  Pbar absorbing window  Neutron absorbers  Proton shield  Detector support structures  Muon beam stop 3/17/2010 - Mu2e WGM17

18. Muon Channel Issues Losing L2 manager  In talks with potential replacement Potential need to rotate central collimator is an unexpected complication. Most of this L2 is optimization, engineering and integration. 3/17/2010 - Mu2e WGM18

19. Tracker MECO had no viable, proven tracker design and their tracker requirements were not fully developed or documented. The tracker environment:  For 200 ns after the arrival of the proton beam at the production target, the tracker sees a beam flash of up to 8 MHz/wire. The flash is primarily electrons.  700 ns after the arrival of the proton beam at the production target, the live gate is opened and the tracker has to be fully efficient.  During the live gate the tracker will see rates of up to 170 kHz per wire. Rate is dominated by protons which are 10x minimum ionizing. 19 e from  decay 3/17/2010 - Mu2e WGM

20. Tracker Rate handling requirements dictates small diameter straws and fast gas  Open geometry drift chamber still under consideration. Has obvious advantages and concerns. Resolution in tracker dominated by multiple scattering. Requires minimum of material and operation in vacuum. Sophisticated pattern recognition and fitting required to obtain precision momentum measurement.  Trying to get simulations in place to evaluate this. Going slow.  Coordinate information along straw length may help. Pads, charge division, time division Concern about rate performance in each case. Largest cost is readout electronics.  Initiating work at LBL to modify BaBar Elefant chip. Faster clock speed Bigger buffer Lower power for operation in vacuum. 203/17/2010 - Mu2e WGM

21. Tracker R&D Mechanical prototypes of 2.5 m straws Rate studies of straws Preparing to study charge/time division. I tracker beam test at Frascati Investigating pads etched into straw copper cladding. 213/17/2010 - Mu2e WGM

22. Tracker Issues No L2 Manager.  Working on solving this soon. Need fairly advanced simulations to choose between tracker alternatives.  I’m not confident we will have these before Thanksgiving. May have to punt on this for CD-1, make our best guess and identify unanswered questions as significant technical risks. We don’t know how to calibrate this device.  This is a big problem. Potential show stopper. Need conceptual mechanical designs  Tracker support  Gas manifolds  Electronics interface  Cables/fibers/Data flow  Water cooling Need conceptual design for electronics downstream of the modified Elefant chip. 3/17/2010 - Mu2e WGM22

23. Calorimeter Calorimeter provides second independent measurement of energy, trajectory and timing. Could also be used in trigger.  Can’t compete with tracker on energy resolution.  Extrapolation of measured helix in tracker to calorimeter (in space and time) may help to expose mis-reconstructed events in tracker. This has yet to be demonstrated with simulations INFN is taking the lead on the calorimeter  Beam test in Frascati of LYSO crystals  Position and timing resolution excellent 50-100 ps, 3-4 mm for 100 MeV e   Energy resolution not yet understood. 233/17/2010 - Mu2e WGM

24. Cosmic Ray veto Cosmic rays can create background  Muons can decay in the detector solenoid.  Muons can interact in the stopping target, detector or other material and make electrons.  Muons can scatter in the stopping target or other material and be mistaken for an electron.  Muons can interact in material, make other particles (photons or hadrons) which then interact and produce electrons. 243/17/2010 - Mu2e WGM

25. CRV Issues Background from cosmic rays must be << 1 event over the course of the run (2  10 7 s)  MECO claimed that this required an efficiency of 99.99% for the CRV. We have to confirm this number for our specific application.  Lots of neutrons in detector hall from both targets and proton dump that could fire the veto and significantly reduce live time. Lots of neutron shielding Looking at ways to reduce CRV sensitivity to neutrons.  Thicker scintillator  Pattern recognition with multiple layers  RPCs? 3/17/2010 - Mu2e WGM25

26. Conventional Construction We need a detector hall, a connected cryo building and a new beamline. We have to understand the shielding requirements for the proton beam and the production solenoid.  We have assumed 21 feet  Drives depth of detector hall Trying to understand stakeholder requirements, as they are now known, so we can do the Title I design. 263/17/2010 - Mu2e WGM

27. Trigger and DAQ No work done yet on this system No L2 manager yet. Bob T is going to organize some engineering effort in CD to put together a conceptual design for a trigger and DAQ system so we will have something for a CDR.  CD is particularly interested in looking at a “triggerless” DAQ Triggerless == no hardware trigger. Some potential interest in DAQ from SLAC but probably no movement until the fate of SuperB is decided. 3/17/2010 - Mu2e WGM27

28. Schedule 3/17/2010 - Mu2e WGM28 CD-1CD-2CD-3 Best guess schedule

29. CD-1 Timeline 3/17/2010 - Mu2e WGM29 Lehman CD-1 ReviewMarch 1, 2011 Director’s ReviewFeb. 1, 2011 CDR completeJan. 15, 2011 Final cost & schedule and associated documentation. Jan. 15, 2011 L2 CDR contributions submittedDec. 1, 2010 Director’s Design ReviewNov. 1, 2010 L2 Design ReviewsOctober, 2010 Time

30. Risk Registry 3/17/2010 - Mu2e WGM30 Started on Risk Registry 30 risks identified so far from half of the L2 systems

31. Documentation Early drafts of:  Quality Management Plan  Project Management Plan  Security Vulnerability Assessment  Configuration Management and Change Management Plan  Life Cycle Costs  Risk management Plan  Contingency Rules  Integrated Safety Management Plan 3/17/2010 - Mu2e WGM31

32. Scientific Salaries Until recently scientific salaries were not charged to projects  Considered part of the base program. Drive to have some scientists on-project comes from DOE In December, 2009 the Lab documented it’s policy  Memo from Cindy Conger, FNAL CFO, Mu2e-doc-763 In response, I wrote a memo documenting my interpretation of the policy, Mu2e-doc-764  Project Managers and L2 managers on-project if they work for FNAL  AD, TD, APC scientists working on accelerator modifications, the external beamline, the primary production target, the proton beam absorber, extinction or any other activity generally associated with accelerator systems will be charged to the Project.  The solenoids are considered part of the detector. Scientists working on them are off-project. 3/17/2010 - Mu2e WGM32

33. IPT and Tech Board IPT has been established. We have met 3 times. One IPT meeting was devoted to NEPA  Fermilab ES&H, Fermi Site Office, Chicago office and Germantown all participated.  Trying to understand if an EA will be required or if the categorical exclusion can apply. Need to do pbar shielding assessment before we can make a decision  Need to schedule a follow-up meeting. Tech Board has been meeting for many months  Current concept for the detector hall emerged from a series of intense TB meetings  Now working on WBS, resources, risks, etc. 3/17/2010 - Mu2e WGM33

34. University Participation Mu2e is very Fermi-centric. Having a hard time getting universities involved. Universities that are involved are making a big difference  Boston U  Rice  Virginia  CUNY Opportunity to get some critical people at universities involved if we can provide some support to hire RAs.  I have been talking to DOE about this. They are helping, but can’t do everything we would like.  Nuclear side is a problem. 3/17/2010 - Mu2e WGM34

35. Other efforts to add people The Project bought out 2 Professors from teaching this year to reside at Fermilab and work on Mu2e full time.  Jim Miller, BU, co-spokesperson  Jim Popp, CUNY, significant collaborator on MECO With PPDs help, we are awarding “International Fellowships” to 3 Italians (one senior collaborator and 2 post docs) to work full time on Mu2e at Fermilab.  Strengthen ties with INFN  Convince them we are serious about Mu2e  Hope to eventually get in kind contribution of calorimeter from Italy. New positions that could help Mu2e  Virginia/Fermilab joint faculty/staff position on Intensity Frontier  Intensity Frontier positions in CD With TDs help we are bringing in a senior CERN magnet and accelerator scientist to work on solenoids for a year, starting in August.  Ranko Ostojic 3/17/2010 - Mu2e WGM35

36. 3/17/2010 - Mu2e WGM36 What is required for CD-1? A Conceptual Design Define scientific and technical requirements  The Collaboration is expected to play a major role in this activity. Evaluate alternatives for satisfying the requirements Select a set of preferred alternatives Demonstrate that the preferred alternatives satisfy the requirements. Perform a high-level risk analysis and develop mitigation strategies Identify opportunities for Value Management Cost and schedule Lots of documents and bureaucratic work. R. Ray - Mu2e Collaboration Meeting, Jan. 7, 2010 36

37. Requirements Documents Very few requirements documents have been written to date.  This is the primary area where more Collaboration participation is required. MECO did a good job of documenting the solenoid requirements but a very poor job elsewhere. Mu2e is not doing much better… I am preparing a list of necessary requirements documents that we will show at future WGM to track progress. 3/17/2010 - Mu2e WGM37

38. Action Items Find L2 manager for tracker.  I am close. Get resources required for CD-1 into Primavera Find replacement for Peter Limon  Current plan could fall through. No backup plan at the moment. Prepare list of necessary requirements documents for next meeting. Track at future meetings. 3/17/2010 - Mu2e WGM38