New Compact Low Energy Neutrino Source using Isotope Beta Decay - PowerPoint PPT Presentation

1 New Compact Low Energy Neutrino Source using Isotope Beta Decay Mike Shaevitz Shaevitz - Columbia University - Columbia University Mike Workshop ¡on ¡Low ¡ ¡Threshold ¡ ¡Detectors ¡ ¡for ¡ ¡Detec4on ¡ ¡of ¡Coherent ¡ ¡Neutrino ¡ ¡Sca;ering Dec. ¡ ¡6-­‑7, ¡ ¡2012 Livermore ¡ ¡Valley ¡ ¡Open ¡ ¡Campus, ¡ ¡Livermore, ¡ ¡California

2 Overview • High-power cyclotrons can be used to make an intense, compact neutrino source. • Daedalus CP violation program using 800 MeV proton cyclotrons – High intensity DAR source of ν µ to complement long-baseline neutrino oscillation program – Use NC coherent scattering to search for ν→ ν STERILE with DAR beam • IsoDAR sterile neutrino experiment using a 60 MeV proton cyclotron – Cost effective, intense , compact ν e source from 8 Li isotope decay. – Synergy with industrial interest in medical isotope production • High intensity IsoDAR type ν e source could also be used for a neutral current coherent neutrino scattering experiment – Need to couple the IsoDAR source with a low threshold (~few keV) 10 to 1000 kg detector

DAE δ DALUS 800 MeV Cyclotron System 3 (Under Development) DAR Target-Dump + Ion H 2 (about 6x6x9 m 3 ) Source IsoDAR Cyclotron Injector Cyclotron (Resistive Isochronous) Ring Cyclotron (Superconducting) “Isochronous cyclotron” where mag. field changes with radius, but RF does not change with time. This can accelerate many bunches at once.

4 Columbia, Huddersfield, IBA, Maryland, MIT, PSI, INFN-Catania, INFN –Legnaro, RIKEN, Wisconsin Academics: Neutrino Physicists, Accelerator Physicists And also Scientists at a Corporation Submitted to NIM

5 Phase I: The Ion Source Target/ Ion Superconducting Injector Dump source Ring Cyclotron

6 solenoid source slits & lens diagnostics

7 Beam to be characterized at Best Cyclotrons, Inc, Vancouver This winter (NSF funded) Results to be available by Cyclotrons’13 Conference, Sept 2013, Vancouver

8 We have a workable ion source for a Phase II Target/ Ion Superconducting Injector Dump source Ring Cyclotron IsoDAR: A sterile neutrino experiment On its own!

9 Base Design Injector + 60 MeV/n @ 5 mA of H 2 (That’s 10 mA of protons) ~1 mA p machines are made By industry (IBA, BEST) For isotope production

10 Phases III and IV Target/ Ion Base Design Superconducting Injector Dump source Ring Cyclotron Establish the “standard” system And the high-power system

11 Our proposed 800 MeV cyclotron is very similar to the existing Riken, Japan, cyclotron

12 Why Are We Developing These High Intensity Cyclotrons? ⇒ To Make High Intensity Neutrino Sources High Intensity p(60 MeV) → 9 Be / 7 Li (shielding) Injector Cyclotron → Lots of 8 Li (60 MeV protons) 8 Li → 8 Be + e − + ν e ν µ Decay-at-Rest High Intensity Cyclotron (~800 MeV protons) (DAR) Beam Dump e + µ + ν e proton π + ν µ Oscillations? ν e

13 Daedalus CP Violation Program in Combination with Longbaseline Neutrino Exps

14 Long-Baseline Neutrino Experiment (LBNE) (Being set up to measure the mass hierarchy and ν CP violation) Phase 1: 700kW beam with 10kton LiqArgon Detector on surface (data in ~2023) Phase 2: >1MW beam with >20kton LiqArgon Detector underground

15 Main Limitation of LBNE Approach Long Baseline experiments are usually low in antineutrino statistics → due to lower π − production and ν cross section ν ν … and the backgrounds are significant compared to signal plus the antineutrino beam has neutrino contamination

16 DAE δ ALUS Experiment: Antineutrino Source for CP Measurements ν µ High Intensity Cyclotron (~800 MeV KE proton) Decay-at-Rest Dump e + µ + (DAR) Beam ν e proton π + ν µ Oscillations? ν e • Combine: 1MW 2MW 5MW – High statistics Dae δ alus Antineutrinos ν µ →ν e Single Ultra-large Detector With Free Protons as Targets – High statistics (Oil or Water) plus Longbaseline Multiple-baselines from Oil or Neutrinos cyclotron sources. Water ν µ → ν e ( Described in: Conrad/Shaevitz, PRL104,141802 (2010), Alonso et al., arXiv:1006.0260 [physics.ins-det] and 1008.4967 [hep-ex] )

17 Using Cyclotron Neutrino Sources to Search for Sterile Neutrinos

18 Possible Oscillations to/thru Sterile Neutrinos • Several hints for neutrino oscillations with large Δ m 2 ~ 1 eV 2 – Cannot be explained with the 3 standard neutrinos ( ν e , ν µ , ν τ ), since already have two Δ m 2 value at 2.5 × 10 -3 and 7.6 × 10 -5 eV 2 – And there are strong constraints that there are only 3 neutrinos with normal weak interactions ⇒ Need a new type of neutrino that does not interact weakly and therefore is “sterile” • Sterile neutrinos – Have no weak interactions (through the standard W/Z bosons) – Would be produced and decay through mixing with the standard model neutrinos – Can affect oscillations through this mixing

19 LSND and MiniBooNE Indications of ν ν e Appearance MiniBooNE Allowed Regions ν ν µ →ν ν e

ν e Disappearance Has Maybe Been Observed? ν 20 ⇒ Reactor Antineutrino Anomaly Daya Bay ν e →ν s ? RENO 3 ν 4 ν Region to Explore Current Reactor Older Reactor for Sterile Neutrinos Experiments Exps at Close Distances R = 0.927 ± 0.023 (3.0 σ ) § At least three alternatives: Ø Wrong prediction of ν -spectra ? Ø Bias in all experiments ? Red: 3 ν sin 2 (2 θ 13 ) = 0.15 Ø New physics at short baselines: Blue: 4 ν ∆ m 2 new ≫ 2 eV 2 and sin 2 (2 θ new )=0.12, Mixing with 4 th ν -state with sin 2 (2 θ 13 ) = 0.085 arXiv: 1204.5379

21 Many Ideas for Future Experiments • Establishing the existence of sterile neutrinos would be a major result for particle physics but … .. • Need definitive experiments – Significance at the > 5 σ level – Observation of oscillatory behavior within detector • The disappearance of neutrinos using the neutral current interactions is a strict probe of active-to-sterile oscillations. – Observation of oscillations for coherent NC scattering would definitively establish the existence of sterile neutrinos.

22 Future Experimental Oscillation Proposals/Ideas Type of Exp App/Disapp Osc Channel Experiments Nucifer, Ricochet, ν e →ν e Reactor Source Disapp SCRAMM, NIST, Neutrino4, DANSS Baksan, LENS, Borexino, ν e →ν e Radioactive Sources Disapp SNO+, CeLAND, Daya- ( ν e → ν e ) Bay ν e →ν e Isotope Source Disapp IsoDAR ν µ →ν e Pion / Kaon Decay- Appearance OscSNS, CLEAR, DAE δ ALUS, KDAR at-Rest Source & Disapp ν e → ν e ( − ) MINOS+, MicroBooNE, ν µ → ν e , ν µ →ν e Accelerator ν using Appearance LAr1kton+MicroBooNE, Pion Decay-in-Flight & Disapp ν µ → ν µ , ν e → ν e CERN SPS ν e → ν µ , ν e →ν µ ν STORM at Fermilab Low-Energy Appearance ν -Factory ν µ → ν µ , ν e → ν e & Disapp

23 Very-short Baseline Oscillation Experiments ν - Source ν - Detector Radioactive Source or Isotope Source or Reactor Source or Proton into Dump Source ( ) 1/ L 2 flux rate modulated by Prob osc = sin 2 2 ! " sin 2 # m 2 L / E • Can observe oscillatory behavior within the detector if neutrino source has small extent . – Look for a change in event rate as a function of position and energy within the detector – Bin observed events in L/E (corrected for the 1/L 2 ) to search for oscillations • Backgrounds produce fake events that do not show the oscillation L/E behavior and are easily separated from signal

24 Pion or Kaon Decay-at-Rest Neutrino Sources

25 Decay-at-Rest (or Beam Dump) Neutrino Sources Cyclotron or Other Proton Source Decay-at-Rest gives ν µ ( >800 MeV proton for π production) isotropic neutrino source Dump e + µ + ν e proton π + ? e c n a r a ν µ e p π − p a s i D Captures ν e before decay Appearance? ν e Each π + decay gives one ν µ , one ν e , and one ν µ with known energy spectrum ~1 ma of 800 MeV protons (like LSND) ⇒ 0.17 π + /proton ⇒ 2.3 × 10 24 ν / yr

26 Using Coherent Scattering with DAR Beam arXiv: 1201.3805 100kg 76 Ge 456kg 40 Ar 5yr 5yr

27 IsoDAR Experiment Isotope Decay-at-Rest Neutrino Source ( ν ν e Disappearance )

28 IsoDAR ν ν e Disappearance Exp • High intensity ν e source using β -decay at rest of 8 Li isotope ⇒ IsoDAR • 8 Li produced by high intensity (10ma) proton beam from 60 MeV cyclotron ⇒ being developed as prototype injector for DAE δ ALUS cyclotron system • Put a cyclotron-isotope source near one of the large (kton size) liquid scintillator/water detectors such as KAMLAND, SNO+, Borexino, Super-K … . cyclotron protons Blanket/ Detector Target Shield • Physics measurements: – ν e disappearance measurement in the region of the LSND and reactor- neutrino anomalies. – Measure oscillatory behavior within the detector. Phys Rev Lett 109 141802 (2012) arXiv:1205.4419