Tuesday, February 5, 13 Brief History MARE ( M icrocalorimeter A - PowerPoint PPT Presentation

MARE Flavio Gatti Numass 2013 , Milano Bicocca Tuesday, February 5, 13

Brief History MARE ( M icrocalorimeter A rray for R henium-187 E xperiment) is the  merging of two projects in Genoa (MANU) and Milan (MI-Beta), in competition. 1 MGaleazzi et al, 2001  0.1 sin ( θ ) SIMPSON '81 2 HIDDEMAN '95 0.01 Re - 187 0 200 400 600 800 1000 2 Heavy Neutrino Mass (eV / c ) Tuesday, February 5, 13

Brief History At the time of LTD-12 (2007) in Paris, due to di ffj culties in achieving  eV resolution with Rhenium Metal and compounds, we proposed to full exploit the idea of De Rujula and Lusignoli (1982). First trial in 1996... but the technology of Low Temperature Detector  was not mature enough. Presently large arrays (8x8 to 32x32 pixels) of 2eV FWHM are  successfully operated in a few laboratories (GSFC NASA, NIST, SRON) Bi  F Gatt et al, 1996 Courtesy of GSFC  Cu NASA  nitride    “Mushroom” ¡shaped ¡to ¡cover ¡the ¡     Tuesday, February 5, 13

Neutrino mass calorimetric measurements using 163 Ho Electron Capture can be used for searching neutrino mass: the  spectrum is a superimposition of lines with Breit-Wigner shape by A.Nucciotti 4 Tuesday, February 5, 13

Kinematic Measurement The electron spectrum for a typical (super) allowed decay Nuclear Matrix Fermi 3 bodies phase space factor element factor A typical simulated beta spectrum as seen by a finite time and energy resolution instrument: pile-up and Δ E spread are the consequences. by A.Nucciotti 5 Tuesday, February 5, 13

MC for sensitivity prediction by A.Nucciotti Text Take this number as reference: running time and pixels number can be modulated upon you  performance parameters of you detectors. 6 Tuesday, February 5, 13

Sensitivity vs Q EC , resolution, unresolved pile-up by A.Nucciotti Example: Windows 1 eV limits: 1) 1 year data taking with 64 detectors @ 50-500 evs/s within the present RD. 2) 1 year data taking with 2500 to 25000 detectors @ 50-500 evs/s if Q around 2.2 a sensivity of 0.2-0.4 eV achievable. There is not a final word on Q value (our preliminary measurement of 1996 pointed to 2.8 keV) Tuesday, February 5, 13

Neutrino mass calorimetric measurements using 163 Ho in a microclorimeter 163 Ho  163 Dy* + ν e, T 1/2 about 4500  10 11 -10 13 atoms per detector.  Use of metallic micro-calorimeters  eV resolution with established  technology. Self calibration  better confidence in data energy calibration and stability,  data taking live time e ffj ciency . Full energy absorption and fast thermalization requires metallic Ho in metal  absorber. The major problem is the preparation of the absorbers for such kind of  materials that easily forms strong oxides. Ho-oxide Tuesday, February 5, 13

1 st Ho-163 production Er-162(n th ,g)Er-163  Ho-163  has 480 barn cros.sect (good yield!). Er-162 have 0.2% natural abundance  Drop of Ho-Cl Needed enriched Er-162 at level of  20%-40% Bi Needed pure sample of Er(oxide): not Si  easy! Ir Other stable isotopes:164, 166, 167,  168 don’t give out long lived 14 eV FWHM radioactive contaminant. sulla Baseline First attempt in 1 MW reactor of 5 mg  Yield: 2x10 11 Ho-163/3x10 15 Er-162  from CHEMGAS-39% enrichment (10h irradiation in 1MW reactor) First production has been tested  using a calorimeter as external 9 Tuesday, February 5, 13

2nd Ho-163 production New sample from  IsoFlex (USA- RUSSIA) 120 h irradiation  Gamma  spectroscopy of sample as received. First outlook: much  more radioactive isotopes then M R Gomes and Courtesy of ITN/IST -ID Lisboa expected from the G.Pizzigoni first sample extrapolation. Sample origin? this  second sample comes from Russia isotope separation plants. Previous: US or France? Tuesday, February 5, 13

Neutrino mass calorimetric measurements using 163 Ho in a microclorimeter � Thermo-reduction is needed: mixing with compound the reduce the Ho- oxide Ho Metal � Y 5 Si 3 is one of the most stable and metallic compound with high chemcal reduction capability for rare earth. Used for preparation of rare earth superconductive compound (expertise at the University od Genova) � Y 5 Si 3 allows to trap Oxygen in Y neighboring or gives O2 gas � The thermo-reduction will give out Y 5-y Ho y Si 3 M.Galeazzi � The Y 5-x Ho x Si3 can be used � As thin film in gold absorber � As target for implantation � Low temperature properties � under control Tuesday, February 5, 13

YSi: Ho-163 compound Gamma spectrum of Ysi:Ho-163 (after chemical thermo-reduction) Eu lines used as tracker Text mostly Ge background Tuesday, February 5, 13

A calorimeter with YSi:Ho-163 under measurement fabrication of TES u-cal for  measurement of YSi:Ho as detector Tuesday, February 5, 13

Thick films of YSi:Ho-163 Assembled a set-up for grow thick film of YSi:Ho on absorbers and  finally on the array. Presently we have prepared Tin-single crystal-YSi:Ho-Tin thin film  “sandwich” absorber for test in MiBocca Conclusion: the Ho-163 film growth method of Ho-163 embedding  method is viable and in advanced status of testing 14 Tuesday, February 5, 13

2nd method of embedding: implantation M R Gomes, Lisboa Tuesday, February 5, 13

Investigation of Gold absorber e fg ect of Ho in gold absorber M. R. Gomes M. Galeazzi Study of effective implantation profile with RBA method Preparation of sample with Ho Er mixture as expected in the final configuration Conclusion: the implantation in gold Specific heat measurement between is a second viable method and need 0.05-300 mK a test on a detector (LNF) Tuesday, February 5, 13

Ho-163 in Goddard ‘type’ array 163 Ho TES array NASA/GSFC type Preliminary agreement for making spectra of Ho-163: The agreement will be fixed as soon as the method of embedding will be fixed: evaporation or Implantation. 17 Tuesday, February 5, 13

MKIDs R&D @ MiB Tuesday, February 5, 13

Active Collaboration � U. of Genova � U. of MIlano Bicocca � Peter Day (Caltech-JPL) @ MiB � U.Lisboa – CFNUL � NASA GSFC,U. Wisconsin, � NIST Boulder � U. Florida - U. Miami � U. of Wisconsin � PTB � FBK Trento Italy Tuesday, February 5, 13

Conclusions  Ho-163 EC decay is a viable solution for neutrino mass measurements with the present technology of Low Temperature Detectors.  We have chosen Reactor Production even if there are radioactive impurities.  Thermal-reduction of Ho-oxides with Y based compound provides also a method of first purification. Further purification can be done at magnetic separator.  Options with Y compound or implanted gold absorber have been tested separately and are both viable absorber for microcalorimeters.  The work is under way and we expect to take soon a decision on how to put Ho-163 in microcalorimeter arrays. Tuesday, February 5, 13