1 / 33

Measuring q 13 with Reactors Stuart Freedman HEPAP July 24, 2003 Bethesda

Measuring q 13 with Reactors Stuart Freedman HEPAP July 24, 2003 Bethesda. d 2. d 1. Detector 2. Detector 1. Reactor. MNSP Matrix.  12 ~ 30°. tan 2  13 < 0.03 at 90% CL.  23 ~ 45°. Mass Hierarchy. Figuring out CP for leptons. Minakata and Nunokawa, hep-ph/0108085.

mendel
Télécharger la présentation

Measuring q 13 with Reactors Stuart Freedman HEPAP July 24, 2003 Bethesda

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Measuring q 13 with Reactors Stuart Freedman HEPAP July 24, 2003 Bethesda d2 d1 Detector 2 Detector 1 Reactor

  2. MNSP Matrix 12 ~ 30° tan2 13 < 0.03 at 90% CL 23 ~ 45° Mass Hierarchy

  3. Figuring out CP for leptons Minakata and Nunokawa, hep-ph/0108085

  4. The Basic Idea 1/r2 Pee, (4 MeV) eflux ?

  5. First Direct Detection of the Neutrino E = 2200 keV n e e+ E = 511 keV E = 511 keV n m Reines and Cowan 1956

  6. Neutrino Spectra from Principal Reactor Isotopes

  7. Inverse Beta Decay Cross Section and Spectrum

  8. Inverse Beta Decay Signal from KamLAND from 12C(n, g ) tcap = 188 +/- 23 msec

  9. 20 m KamLAND 4 m Chooz 1m Long Baseline Reactor Neutrino Experiments Poltergeist

  10. CHOOZ

  11. CHOOZ

  12. KamLAND

  13. Future 13 Reactor Experiment detector 1 detector 2 Ratio of Spectra Energy (MeV) Two Detector Reactor Experiment Spectral Ratio

  14. Sensitivity to sin2213 at 90% CL cal relative near/far energy calibration norm relative near/far flux normalization Reactor I 12 t, 7 GWth, 5 yrs Reactor II 250 t, 7 GWth, 5 yrs Chooz 5 t, 8.4 GWth, 1.5 yrs fit to spectral shape Ref: Huber et al., hep-ph/0303232 Reactor-I: limit depends on norm (flux normalization) Reactor-II: limit essentially independent of norm statistical error only

  15. We need accelerators and reactors--Reactors first! Reactor Neutrino Measurement of 13 • No matter effect • Correlations are small, no degeneracies • Independent of solar parameters 12, m212 Sensitivity to sin2213 Ref: Huber et al., hep-ph/0303232 • sin2213 < 0.01-0.02 @ 90 CL within reach of reactor 13 experiments • Knowing 13 is useful for the “intelligent design” of a CP experiments. 10-3 10-2 10-1

  16. Huber et al hep-ph/03030232

  17. ~20000 ev/year ~1.5 x 106 ev/year Kr2Det: Reactor 13 Experiment at Krasnoyarsk Features - underground reactor - existing infrastructure Detector locations constrained by existing infrastructure Reactor Ref: Marteyamov et al, hep-ex/0211070

  18. Lnear= 115 m, Lfar=1000 m, Nfar = 16000/yr Ratio of Spectra Ratio of Spectra Kr2Det: Reactor 13 Experiment at Krasnoyarsk Energy (MeV) Ref: Marteyamov et al., hep-ex/0211070.

  19. Proposal for Reactor 13 Experiment in Japan Kashiwazaki-7 nuclear power stations, World’s most powerful reactors - requires construction of underground shaft for detectors far near near Kashiwazaki-Kariwa Nuclear Power Station

  20. Kashiwazaki:Proposal for Reactor 13 Experiment in Japan far near near 70 m 70 m 200-300 m 6 m shaft, 200-300 m depth

  21. q13 at a US nuclear power plant? Site Requirements • powerful reactors • overburden • controlled access

  22. Berkeley 230 miles Pasadena 200 miles

  23. 2 underground  detectors Diablo Canyon Nuclear Power Plant 1500 ft • Powerful: Two reactors (3.1+ 3.1 GW Eth) • Overburden: Horizontal tunnel could give 800 mwe shielding • Infrastructure: Construction roads. Controlled access. Close to wineries.

  24. Detector Concept

  25. Requirements: Overburden and Large Detectors Detector Event Rate/Year ~250,000 ~60,000 ~10,000 Statistical error: stat ~ 0.5%for L = 300t-yr

  26. Overburden FAR: ~ 600-800 mwe NEAR: ~ 300-400 mwe Neutrino Detectors at Diablo Canyon • 2 neutrino detectors, railroad-car size • in tunnels at (variable) distance of NEAR/FAR I: 0.5-1 km FAR II: 1.5-3 km Possible location Crowbar Canyon Parallel to Diablo Canyon Existing road access Possibility for good overburden Tunnels in radial direction from reactor Crowbar Canyon parallel to Diablo Canyon

  27. Optimization ‘far-far’L1=6 km L2=7.8 km ‘near-far’L1 = 1 km L2 = 3 km MC Studies Oscillation Parameters: sin2213 = 0.14 m2= 2.5 x 10-3 eV2

  28. Reactor 13 13 Reactor results will define the future of CP searches in the lepton sector and complement accelerator experiments Timescale and Size of a 13Reactor Project Moderate Scale ( < $50M )Medium-size, low-energy experiment Little R&D necessary (KamLAND, SNO, CHOOZ)Construction time ~ 2-3 yrsStart in 2007/2008? The Particle Physics Roadmap (in the US) 2000 2005 2010 m223, 23 CP

  29. Conclusions • Top priorities in neutrino physics include pinning down • MNS matrix elements and discovering CP violation. • We will need a number of experiments to resolve ambiguities from matter effects and correlations. • Reactor experiments and accelerator experiments are complementary. • Reactor experiments have the potential of being faster, cheaper and better for establishing the value of q13. • Executing a reactor experiment at an appropriate site should be put on a fast track.

More Related