1 / 24

MARE an experiment for the calorimetric search of m n with sub eV sensitivity

MARE an experiment for the calorimetric search of m n with sub eV sensitivity. F.Gatti On the behalf of the Collaboration University and INFN of Genoa TAUP, Sendai, Sep. 14th 07. MARE: Microcalorimeter Arrays for a Rhenium Experiment.

deacon
Download Presentation

MARE an experiment for the calorimetric search of m n with sub eV sensitivity

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. MAREan experiment for the calorimetric search of mn with sub eV sensitivity F.Gatti On the behalf of the Collaboration University and INFN of Genoa TAUP, Sendai, Sep. 14th 07 TAUP2007, Sendai, 14.9.07

  2. MARE: Microcalorimeter Arrays for a Rhenium Experiment • Proposal of a direct measurement of neutrino mass (MARE) with sub eV sensitivity. • MARE want to exploit the true calorimetric method in conjunction with the eV energy resolution of the cryogenic detectors. • MARE want to achieve a model independent measurement • MARE is foreseen to develop the research program trough different phases: • MARE I: R&D and test experiment with eV sensitivity • MARE II: fixing the technology and measurement in the sub eV ( ~0.1 eV) range. TAUP 2007, Sendai, 14.9.07

  3. MARE: Microcalorimeter Arrays for a Rhenium Experiment Università di Genova and INFN Genova,Italy Goddard Space Flight Center, NASA, Maryland, USA GSI, Darmstadt, Germany Kirkhhof-Institute Physik, Universität Heidelberg, Germany Università dell'Insubria,Italy Univ. Milano-Bicocca and INFN Milano-Bicocca, Italy NIST, Boulder, Colorado, USA ITC-irst, Trento and INFN Padova,Italy PTB, Berlin, Germany University of Maryland, Maryland, USA University of Miami, Florida, USA University of Florida, Gainesville, Florida, USA Università Roma “L a Sapienza” and INFN Roma I, Italy SISSA, Trieste, Italy University of Wisconsin, Madison, Wisconsin, USA TAUP 2007, Sendai, 14.9.07

  4. Re-187 ßi, Os Calorimetric beta spectroscopy The source is embedded in the detector Advantages: • Measurement of whole energy of the decay Ei=i+i dN() = A i wi  i d no model dependent corrections for atomic and molecular final states. no correction for nuclear recoil energy and for electron energy losses. Disadvantages: • Beta Source inside the detector  all spectrum must be acquired: but interesting area proportional to only mc2 E Re187 : lowest Q ~ 2.5 keV. Re187: mc2 E ~1/400 of H3 dN/A   TAUP 2007, Sendai, 14.9.07

  5. Thermistor Ir-Au TES on Si Thermal contact High purity epoxy Electrical & Heat link Al -1% Si wires 15 μm diam., 1mm length Absorber Re single crystal (99.99% purity) typical dim. 300x300x300 μm surfaces cleaned to optical level annealed at 1300ºC in UHV 63% of 187- Re An exemple of ¨rhenium microcalorimeter¨ TAUP 2007, Sendai, 14.9.07

  6. MnKa1,2 energyspectrum TES R vs T How the detector works TAUP 2007, Sendai, 14.9.07

  7. Short History • In 1985 the use of Re in cryogenic detectors has been proposed by S.Vitale (Genoa) • In 92: first calorimetric observation of the 187-Re beta decay • 96-99: achieved performance for execution of a first log run 1996 1992 660 eV fwhm 30 eV fwhm TAUP 2007, Sendai, 14.9.07

  8. Other type of TAUP 2007, Sendai, 14.9.07

  9. TAUP 2007, Sendai, 14.9.07

  10. known sources of systematics • The absorber modulates the Eendpoint: • Eendpoint = (Q-me ) – (ef-EFermi)-DBlattice • Atomic long term metastable excited states: • <7x10-5 • Absorber thermal efficiency: • in superconducting Re: ~ 1 down to 90 mK • detector response function (energy dependence, shape,...): • material dependent, good absorber show gaussian like funct. and approx flat energy dependence • condensed matter effects: • BEFS observed in Re and AgReO4 improve data and modeling • 187Re decay spectral shape: • improve F(Z,E) and S(E) • energy dependent background: • low energy emission in the surrounding materials and radioactivity to be • pile-up and rejection efficiency • investigation with MC methods • other analysis artifacts • under investigation with MC methods • energy surface escape: < 10-4 TAUP 2007, Sendai, 14.9.07

  11. Sensitivity: analytic formula vs MC MARE I MARE II TAUP 2007, Sendai, 14.9.07

  12. TAUP 2007, Sendai, 14.9.07

  13. TAUP 2007, Sendai, 14.9.07

  14. TAUP 2007, Sendai, 14.9.07

  15. Bi Cu nitride MARE II: Detector and read-out technologies • Mo/Au TES at GFSC/NASA • Electron-beam deposited • Tc ~ 0.1 K • Noise-mitigating normal-metal stripes • Absorbers joined to TES in micro-fabrication • “Mushroom” shaped to cover the gaps • Emphasis on absorbers needed for Constellation-X reference design • 0.25 mm pitch (TES is 0.13 mm wide) • 92% fill factor • 95% QE at 6 keV TAUP 2007, Sendai, 14.9.07

  16. MARE II: Detector and read-out technologies GSFC/NASA Group TAUP 2007, Sendai, 14.9.07

  17. Metal contact Re TES TES Re SiO Re Suspended SiN menbrane MARE II: Detector and read-out technologies Study of the optimal detector concept (Genoa Group) Improve risetime  direct contact Absorber-TES Improve resolution  minimization of not useful materials Provide a design fully compatible with usual planar lithography tech.  large scale integration Genoa Group TAUP 2007, Sendai, 14.9.07

  18. Characterization with 55Fe-Source: 'Curie' Kα1 Kα2 Kα Trigger level energy resolution EFWHM = 2.7 eV resolving power 2200 non-linearity at 6keV: < 0.8% M T MARE II: Detector and read-out technologies Heidelberg Group TAUP 2007, Sendai, 14.9.07

  19. 50000 5000 100 100 NIST 400 100 100 MARE II: Detector and read-out technologies TAUP 2007, Sendai, 14.9.07

  20. MARE II: Detector and read-out technologies TAUP 2007, Sendai, 14.9.07

  21. A possible sensitivity scenario for MARE II TAUP 2007, Sendai, 14.9.07

  22. A further possibility: not only 187Re • Eletron Capture Decay provides another tool for calorimetric mass measurements • 163Ho is the most suited, The end point of the highest capture line is sensitive to n mass ( A De Rujula, 1983). • Implanted 163Ho is a source with tunable activity independent form the absorber masses • Minimization of the absorber mass  minimum required by the full absorption of the energy cascade  resolution less dependent from the activity • Different systematics than 187 Re  increase confidence level TAUP 2007, Sendai, 14.9.07

  23. TAUP 2007, Sendai, 14.9.07

  24. Concluding remarks • Petcov @ vMass07: “if Katrin don’t see signal … we need to go at 5x10-2 eV!” www.ge.infn.it/~numass • Pastor @ vMass07:“ cosmology can set new constraints on the mass in the ten year … but a laboratory measurement is needed, as in the case of neutrino oscillation at the reactor (Kamland) respect to the astrophysical evidence.” www.ge.infn.it/~numass • Thermal detectors can achieve resolution of the 1 eV in a short time and can be used for a very high statistics experiment expected sensitivity in the KATRIN range or better, in future. • EC decay is considered as second tool • The overall technology is not fully tested for application to beta decay  an huge effort of a large community is needed  new collaborators are welcome TAUP 2007, Sendai, 14.9.07

More Related