1. 1 Peter Kammel Mu2e Test Run at PSI July 09 n Purpose of short presentation Run coordination Update to full collaboration and potential input n Structure Overview Status proton setup Status neutron detectors Simulations Run plan sketch Please excuse logistic discussion and lack of photos

2. 2 People n Illinois Peter, Dave, Peter Winter, Michael, Alex, Chris, Greg n FNAL Vadim Los Alamos Haruo, Tito n Boston Justin n Amherst KK n Imperial Androula Alekou, Jaroslaw Pasternak Yoshi Did I miss anybody?

3. 3 References We have received beam time at PSI July-7 to Aug-3 for our Mu2e testrun. Illinois team will arrive July-5. n https://www.npl.uiuc.edu/cgi-bin/twiki/bin/view/Main/MuEGroup https://www.npl.uiuc.edu/cgi-bin/twiki/bin/view/Main/MuEGroup n http://www.npl.illinois.edu/elog/mu2e/capture/ http://www.npl.illinois.edu/elog/mu2e/capture/ n We’ll set up a presence list on webpage

4. 4 Wire Rates vs Time 240 210 180 150 120 90 60 30 0 Time [ns] 10 8 6 4 2 0 Detection-time interval 0 400 800 1200 700 900 1100 1300 Time [ns] Rate [kHz] Rate [MHz] Beam electrons DIO electrons Muon capture protons Initial flash from electrons All Protons Protons hitting tracker Protons are very heavily ionizing – up to 50x times MIPS Rate reduced by thin-walled proton absorbers

5. 5 Effect on Mu2E Naïve calculation CH2: 4x0.5/cos(  )= 480 mg C Al 6x0.2/cos(  )= 280 mg C Bernstein simulation MECO TDR polyethylene 0.5mm, 1,5m long MECO TDR FWHM total ~ 900 keV tracker ~ 400 keV Resolution dominated by absorber straggling

6. 6 Present Knowledge Estimate a’la Measday review n Al yield: 4% theory, 7% exp. extrapolation, as high as 15-20% Si? n Energy spectrum inferred p,d,  composition not known n Ti yield: 3% from V

7. 7 Goal Proton Exp. n 20% absolute, 10% relative spectrum, E>5 MeV ? What do we really need ? n Sys issues Deconvolution  Reconstruction of original f i Absolute calibration  Muon stop  Proton efficiency PID Background  Target l Electrons l Neutrons  Wall l Protons Statistics: 100k ?

8. 8 Relevant Energy >5 MeV or lower ? p vs T R vs T need simulation geom acc vs. E p

9. 9 Deconvolution Response fct from MC and exp  range distr different thickness active Si target see Vadim’s study Measured Original Assumed f i

10. 10 Charged particle set-up

11. 11 Charged particle setup

12. 12 Detectors

13. 13 Lots of work Additional thanks to Illinois techs, Bernhard and Claude at PSI, Fred and Volodya for DAQ …

14. 14 Status n Main target chamber complete and vacuum tested n Detector mounting and readout boards ready n Basic readout ok, still challenging for 1000 pF detector n Shipping next week n Todo Final complete assembly New detector test and operation, performance Beam setup …. Readout integration Analysis modules …

15. 15 Beam requirements FWHM ~ 75  m Al @ 29 MeV/c, 10kHz rate

16. 16 Run plan sketch n 3 days beam setup n 7 days neutron measurement, plus NaI, Ge?, range etc n 14 days proton measurements Detailed plan still to be worked out, based on systematic issues and statistics discussed in the following slides.

17. 17 Absolute calibration n Muon stops in target Electron telescope (tracking?), separation by lifetime Pb walls and low Z window and detectors MC calculation of efficiency design choice: distance muPC target, 2 muPC? how important is (x,y) target for this and deconvolution Si target calibration n Proton detection efficiency MC (how important is muon stop distribution) Si target calibration

18. 18 Background n Target Michel electrons: E (MIPS 40 KeV/100u), antiCoinc, mu+ Neutrons: ESi*dESi, measurement with absorber, MC, Si target n Wall + Windows low or high Z materials (competing capture and p emission) optimal collimator design, or none? Si target n Chamber gas Air certainly a problem He needs to be estimated Si target Vacuum? Aside on stopping power 100 um Al = 21.6 cm Air = 150 cm He

19. 19 Statistics R obs = R mustop x  x BR R mustop = 10 4 /s  0.02 and 0.005, for 5x5cm2 in 10 and 20 cm dist BR = 0.06 R obs = 3 Hz for 20 cm distance N/day ~ 250k 3 targets, 2 thickness each. 1 week of running. 1 week set-up. Additional time for other measurements.

20. 20 Additional Slides

21. 21 TOF

22. 22 Optimize absorber thickness based on measurement Assumed primary capture spectrum present design

23. 23 Transported Beam Rates 50x10 9 muon stops / second 85,000 muon stops /  bunch Order of magnitude more electrons, although few after the initial flash DAQ turned off for ~700 ns after initial beam pulse e-e- -- e+e+ ++ Entrance Det Solenoid

24. 24 Mu2e Detector Stopping target Straw tracker Electromagnetic calorimeter Beam dump 2T 1T Proton absorber Uniform 1 T magnetic field 10 -3 Torr vacuum Straw-tube magnetic spectrometer for energy measurement Electromagnetic calorimeter for triggering Modest number of readout channels ~20,000

25. 25 Straw Tracker 105 MeV/c Electrons Muon Stopping Target 17 x 0.2 mm, 5 cm dist, r=8.3-6.5 cm

26. 26 Longitudinal Tracker Straw tubes: 5 mm diameter x 2.6 m length 25  m tube thickness 3 planes thick: outer resistive, inner conductive 2800 total Cathode strips: 30 cm x 0.5 cm on outer and inner planes 16,640 total Octagonal geometry: 8 vanes, 8 sides R i =35 cm, L=260 cm ~50 % geometrical acceptance (60°-120°) for conversion electrons Almost co-axial with solenoid axis Fast gas: CF 4 -isobutane Expected resolution: r-  : 200  m z:1.5 mm p:0.180 MeV/c (intrinsic, from GEANT simulation) Stopping Target Helical e - trajectory Straw Tracker PbWO Crystal Calorimeter

27. 27 Tracker Performance Resolution:  (E) = 0.180 MeV Acceptance: ≥ 6 hits in tracker:0.44 E ≥ 103.6 MeV:0.62 pitch angle: 45° ≤  p ≤ 60°:0.88 quality cuts:0.83 match with calorimeter:0.97 Total:0.19 Low-side tail = some loss of events High-side tail = trouble!

28. 28 Calorimeter: Design 4 calorimeter vanes 10 x 45 = 450 array of 30x30x135mm 3 PbWO 4 crystals per vane: 1800 total PWO: fast, rad hard widely used: CMS, Alice, PANDA inexpensive cooled to -25° C to increase light yield Large-area APD readout 2 to avoid nuclear counter effect (and increase light yield) operate in magnetic field

29. 29 Sensitivity and Background Signal & DIO

30. 30 Rates