1. Robert Cooper http://neutrino.indiana.edu/rlcooper

2. SciBath Detector 80 L open volume of mineral oil based liquid scintillator Neutrons recoil off protons, create scintillation 768 wavelength shifting fibers readout IU built custom digitizer: 12 bit, 20 MS / s SciBath Detector for ANNIE -- R.L. Cooper2

3. SciBath Detector 80 L open volume of mineral oil based liquid scintillator Neutrons recoil off protons, create scintillation 768 wavelength shifting fibers readout IU built custom digitizer: 12 bit, 20 MS / s SciBath Detector for ANNIE -- R.L. Cooper3

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5. Sample Neutron Candidate Event 5SciBath Detector for ANNIE -- R.L. Cooper

6. Sample Muon Candidate Event 6SciBath Detector for ANNIE -- R.L. Cooper

7. n /  Particle Discrimination 7SciBath Detector for ANNIE -- R.L. Cooper

8. Low-light LED pulser (Y  Z) Use cosmic rays with known energy deposit (X  Y) requires previous calibration to count photons Detect 6 PEs / MeV  want to improve 8SciBath Detector for ANNIE -- R.L. Cooper Calibrating the SciBath Detector X Energy Deposit (MeV) Y Scintillation Photons Collected Z Signal Voltage (ADCs)

9. Low-light LED pulser (Y  Z) Use cosmic rays with known energy deposit (X  Y) requires previous calibration to count photons Detect 6 PEs / MeV  want to improve 9SciBath Detector for ANNIE -- R.L. Cooper Single-PE LED Calibration Calibrating the SciBath Detector X Energy Deposit (MeV) Y Scintillation Photons Collected Z Signal Voltage (ADCs)

10. Low-light LED pulser (Y  Z) Use cosmic rays with known energy deposit (X  Y) requires previous calibration to count photons Detect 6 PEs / MeV  want to improve 10SciBath Detector for ANNIE -- R.L. Cooper MIP Cosmic Ray Calibration Peak Calibrating the SciBath Detector X Energy Deposit (MeV) Y Scintillation Photons Collected Z Signal Voltage (ADCs)

11. Fermilab Measurement Sites MINOS Near NuMI Target BNB Target 10/11 – 2/12 2/12– 5/12 11SciBath Detector for ANNIE -- R.L. Cooper

12. MI-12 Neutron Background Run Neutron flux ~20 m from target In-line behind beam target (ground) 29 Feb. – 23 Apr., 2012 4.9x10 19 total protons on target (POT) (4.5x10 12 per pulse) 12SciBath Detector for ANNIE -- R.L. Cooper

13. MI-12 Neutron Background Run Neutron flux ~20 m from target In-line behind beam target (ground) 29 Feb. – 23 Apr., 2012 4.9x10 19 total protons on target (POT) (4.5x10 12 per pulse) 13SciBath Detector for ANNIE -- R.L. Cooper

14. MI-12 Beam Time Per PE “Group” HIGH PE group shows beam time structure MEDIUM PE group has few-  s excess – slower neutrons arriving later LOWEST PE group has significant excess – 200  s lifetime from n(p, d)  neutron capture reaction 14SciBath Detector for ANNIE -- R.L. Cooper

15. BNB Neutron Energy Spectrum E n unfolded from PEs spectrum simulation of detector response 2.44 ± 0.34 pulse -1 m -2 (E n > 40 MeV) Lose sensitivity > 200 MeV; Neutron spectrum 20 m from BNB 15SciBath Detector for ANNIE -- R.L. Cooper Raw PE Spectrum In-Beam

16. BNB Neutron Energy Spectrum E n unfolded from PEs spectrum simulation of detector response 2.44 ± 0.34 pulse -1 m -2 (E n > 40 MeV) Lose sensitivity > 200 MeV; Neutron spectrum 20 m from BNB 16SciBath Detector for ANNIE -- R.L. Cooper NOTE: variable PE bin width Raw PE Spectrum In-Beam

17. BNB Neutron Energy Spectrum E n unfolded from PEs spectrum simulation of detector response 2.44 ± 0.34 pulse -1 m -2 (E n > 40 MeV) Lose sensitivity > 200 MeV; Neutron spectrum 20 m from BNB 17SciBath Detector for ANNIE -- R.L. Cooper Unfolded Neutron Energy Spectrum Stat and Syst errors

18. Direction Spectrum High PE protons will be track- like; can be imaged Principle component analysis yields eigenvector Back-projecting direction spectrum tends to point upstream of target ?! Tracking validated with cosmic rays and NuMI beam 18SciBath Detector for ANNIE -- R.L. Cooper High-PE, Proton Direction Spectrum

19. Direction Spectrum High PE protons will be track- like; can be imaged Principle component analysis yields eigenvector Back-projecting direction spectrum tends to point upstream of target ?! Tracking validated with cosmic rays and NuMI beam 19SciBath Detector for ANNIE -- R.L. Cooper

20. Direction Spectrum Sensitive to n(p,d)  reaction and see copious beam-correlated rate Accidental rates too high for capture-gating  statistical sensitivity 20SciBath Detector for ANNIE -- R.L. Cooper

21. Current Studies 2012 measurements at one position with no shielding We are improving SciBath, building concrete shielding Locate a viable location for CENNS & CAPTAIN Survey the area with portable detector 21SciBath Detector for ANNIE -- R.L. Cooper

22. Current Studies 2012 measurements at one position with no shielding We are improving SciBath, building concrete shielding Locate a viable location for CENNS & CAPTAIN Survey the area with portable detector 22SciBath Detector for ANNIE -- R.L. Cooper beam

23. Beam Off-Target Rates (> 0.5 MeV) 23SciBath Detector for ANNIE -- R.L. Cooper Stairwell 9 m from Be beam target 1384 n / 10 16 POT Collimator 8 m from Be beam target 5608 n / 10 16 POT 50 m Absorber 6 m from Fe beam stop 310 n / 10 16 POT 2012 SciBath Loc 20 m from Be beam target 211 n / 10 16 POT Target 90° FOX 20 m from Be beam target 390 n / 10 16 POT Neutron spectrum unfolding underway ≈ 2.7×10 16 / hr

24. Summer 2015 Plans Plan to measure near BNB target building for CENNS, CAPTAIN, and general SBN program (May or June for 1 month) Measure in SciBooNE hall higher energy neutrino-induced neutrons: relevant for ANNIE, microBooNE, and SBN (May or June for 1 month) We want to help the neutron measurement efforts and are eager for additional support: siting, shifts, analysis, etc. 24SciBath Detector for ANNIE -- R.L. Cooper