Robert Cooper

Outline Physics Motivation for CENNS How do we measure CENNS? i.)Neutrino production ii.)Detection iii.)Background suppression The SciBath Detector Future work and conclusions 2FNAL Neutrino Seminar -- R.L. Cooper

Describing the CENNS Signal To probe a “large” nucleus (few × m) Detector signature is the recoiling nucleus Recoil energy that is deposited This is quite small for particle & nuclear physics  Dark Matter 3FNAL Neutrino Seminar -- R.L. Cooper E E M

Structure of the CENNS Signal Predicted scattering rate Recoil energy (M -1 ) and rate (N 2 ) 4FNAL Neutrino Seminar -- R.L. Cooper ≈ 0  protons have little influence square of sum  part of coherence condition nuclear form factor  distribution of neutrons Image from K. Scholberg Cross Sections vs. Energy Here be dragons Coherent 40 Ar electrons

Physics Cases for CENNS 5FNAL Neutrino Seminar -- R.L. Cooper Never been observed! Oscillations (spatially) Form factors Supernova physics Non-standard interactions Irreducible dark matter background

Physics Cases for CENNS 6FNAL Neutrino Seminar -- R.L. Cooper Ar-C data + models Patton et al., arXiv/ ton Ar, 16 m from SNS, 1 year,  = 0 4 th vs 2 nd Form Factor Moments Never been observed! Oscillations (spatially) Form factors Supernova physics Non-standard Interactions Irreducible dark matter background

Physics Cases for CENNS Never been observed! Oscillations (spatially) Form factors Supernova physics Non-standard interactions Irreducible dark matter background 7FNAL Neutrino Seminar -- R.L. Cooper Dark Matter Sensitivity L. Baudis, Phys.Dark Univ. 4 (2014) arXiv:

MiniCLEAN for BNB CENNS A. Hime already gave an excellent review of MiniCLEAN for BNB CENNS measurement ½ ton LAr scintillation detector  100 events / yr 8FNAL Neutrino Seminar -- R.L. Cooper

Neutron Backgrounds Few-MeV neutrons will deposit ~10 keV in LAr Accelerator produces all energies up to 8 GeV Shielding is needed Beam-correlated neutrons mimic neutrino signal 9FNAL Neutrino Seminar -- R.L. Cooper ErEr EnEn M Neutron Scatter on 40 Ar where

Elastic Scattering Connection:, n,  All these particle cause elastic scattering on argon Indistinguishable signal  ~10 keV nuclear recoil 10FNAL Neutrino Seminar -- R.L. Cooper E r ≈ 10 keV Ar E ≈ 50 MeV n E n ≈ 1 MeV  v  ≈ c

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 FNAL Neutrino Seminar -- R.L. Cooper11

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 FNAL Neutrino Seminar -- R.L. Cooper12

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 FNAL Neutrino Seminar -- R.L. Cooper13

Sample Muon Candidate Event 14FNAL Neutrino Seminar -- R.L. Cooper

Sample Neutron Candidate Event 15FNAL Neutrino Seminar -- R.L. Cooper

n /  Particle Discrimination 16FNAL Neutrino Seminar -- R.L. Cooper

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 17FNAL Neutrino Seminar -- R.L. Cooper Calibrating the SciBath Detector X Energy Deposit (MeV) Y Scintillation Photons Collected Z Signal Voltage (ADCs)

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 18FNAL Neutrino Seminar -- R.L. Cooper Single-PE LED Calibration Calibrating the SciBath Detector X Energy Deposit (MeV) Y Scintillation Photons Collected Z Signal Voltage (ADCs)

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 19FNAL Neutrino Seminar -- R.L. Cooper MIP Cosmic Ray Calibration Peak Calibrating the SciBath Detector X Energy Deposit (MeV) Y Scintillation Photons Collected Z Signal Voltage (ADCs)

Fermilab Measurement Sites MINOS Near NuMI Target BNB Target 10/11 – 2/12 2/12– 5/12 20FNAL Neutrino Seminar -- R.L. Cooper

MI-12 Neutron Background Run Neutron flux ~20 m from target In-line behind beam target (ground) 29 Feb. – 23 Apr., x10 19 total protons on target (POT) (4.5x10 12 per pulse) 21FNAL Neutrino Seminar -- R.L. Cooper

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 22FNAL Neutrino Seminar -- R.L. Cooper

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 23FNAL Neutrino Seminar -- R.L. Cooper Raw PE Spectrum In-Beam

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 24FNAL Neutrino Seminar -- R.L. Cooper NOTE: variable PE bin width Raw PE Spectrum In-Beam

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 25FNAL Neutrino Seminar -- R.L. Cooper Unfolded Neutron Energy Spectrum Stat and Syst errors

Validation of Unfolding Techniques Cosmic ray neutron spectrum also unfolded Gordon et al., IEEE TNS 51, (2004) 3427 parameterizes surface neutron flux from Bonner sphere data Energy shape matches, overall scale factor needed 26FNAL Neutrino Seminar -- R.L. Cooper Unfolded Cosmic Neutron Spectrum

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 27FNAL Neutrino Seminar -- R.L. Cooper High-PE, Proton Direction Spectrum

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 28FNAL Neutrino Seminar -- R.L. Cooper

Validation of SciBath Tracking Tracking algorithms validated with NuMI underground data 29FNAL Neutrino Seminar -- R.L. Cooper NuMI Near Cosmic Ray MuonsNuMI Near Beam Muons

Capture-Gated Neutrons at MI-12 At surface, accidental rate (and high primary rate) precludes n(p,d)  capture gating  clear statistical sensitivity to thermal captures 30FNAL Neutrino Seminar -- R.L. Cooper MI-12 After-Beam Timing SpectrumMI-12 After-Beam PE Spectrum

Capture-Gated Neutrons at NuMI NuMI near hall (100 m overburden) capture-gating neutron spectroscopy technique demonstrated (L. Garrison thesis) 31FNAL Neutrino Seminar -- R.L. Cooper NuMI Beam Neutron Capture TimingNuMI Beam Neutron Energy

Capture-Gated Neutrons at NuMI NuMI near hall (100 m overburden) capture-gating neutron spectroscopy technique demonstrated (L. Garrison thesis) 32FNAL Neutrino Seminar -- R.L. Cooper NuMI Cosmic Neutron Capture TimingNuMI Cosmic Neutron Energy

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 33FNAL Neutrino Seminar -- R.L. Cooper

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 34FNAL Neutrino Seminar -- R.L. Cooper beam

Beam Off-Target Rates (> 0.5 MeV) 35FNAL Neutrino Seminar -- R.L. Cooper Stairwell 9 m from Be beam target 1384 n / POT Collimator 8 m from Be beam target 5608 n / POT 50 m Absorber 6 m from Fe beam stop 310 n / POT 2012 SciBath Loc 20 m from Be beam target 211 n / POT Target 90° FOX 20 m from Be beam target 390 n / POT Neutron spectrum unfolding underway ≈ 2.7×10 16 POT / hr

CENNS-10 Goals Develop LAr technology Perform very high-energy neutron calibrations Status Moved to Indiana Planning for calibration at Los Alamos WNR neutron beam FNAL Neutrino Seminar -- R.L. Cooper36

CENNS-10 Goals Develop LAr technology Perform very high-energy neutron calibrations Status Moved to Indiana Planning for calibration at Los Alamos WNR neutron beam FNAL Neutrino Seminar -- R.L. Cooper37 2× R MOD (8” PMT)

Summary of BNB Work for CENNS 38FNAL Neutrino Seminar -- R.L. Cooper MiniCLEAN First CENNS measurement SciBath Fast neutron measurement s ( MeV) Neutrons backgrounds preparatory measurement s EJ-301 Cells Portable array( MeV) LAr hardware testing CENNS kg LAr testing prototype CAPTAIN Low-E neutrino cross sections

Summer 2015 Plans BNB: Plan to measure near BNB target building for CENNS, CAPTAIN, and general SBN program (May or June for 1 month) SciBooNE: Measure high-energy neutrino-induced neutrons and constrain thermal neutron rates from n(p,d)  capture rates: relevant for ANNIE, microBooNE, and SBN (May or June for 1 month) 39FNAL Neutrino Seminar -- R.L. Cooper

BACKUPS 40FNAL Neutrino Seminar -- R.L. Cooper

Structure of the CENNS Signal Predicted scattering rate Recoil energy (M -1 ) and rate (N 2 ) 41FNAL Neutrino Seminar -- R.L. Cooper ≈ 0  protons have little influence square of sum  part of coherence condition nuclear form factor  distribution of neutrons Detection Rate [ton -1 year -1 ]

MI-12 Neutron Background Run Neutron flux ~20 m from target In-line behind beam target (ground) 29 Feb. – 23 Apr., x10 19 total protons on target (POT) (4.5x10 12 per pulse) 42FNAL Neutrino Seminar -- R.L. Cooper

Utility Trailer for BNB Measurement 43FNAL Neutrino Seminar -- R.L. Cooper

CENNS-10 On the Move 44FNAL Neutrino Seminar -- R.L. Cooper

Off-Target Runs 45FNAL Neutrino Seminar -- R.L. Cooper