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
Tuesday, February 5, 13
MARE (Microcalorimeter Array for Rhenium-187 Experiment) is the merging of two projects in Genoa (MANU) and Milan (MI-Beta), in competition.
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SIMPSON '81 HIDDEMAN '95 Re - 187 sin (θ)
Heavy Neutrino Mass (eV / c )
MGaleazzi et al, 2001 Tuesday, February 5, 13
At the time of LTD-12 (2007) in Paris, due to diffjculties 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)
“Mushroom” ¡shaped ¡to ¡cover ¡the ¡
Bi Cu nitride
F Gatt et al, 1996 Courtesy of GSFC NASA Tuesday, February 5, 13
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Electron Capture can be used for searching neutrino mass: the spectrum is a superimposition of lines with Breit-Wigner shape
by A.Nucciotti Tuesday, February 5, 13
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The electron spectrum for a typical (super) allowed decay
3 bodies phase space factor Fermi factor Nuclear Matrix element
A typical simulated beta spectrum as seen by a finite time and energy resolution instrument: pile-up and ΔE spread are the consequences.
by A.Nucciotti Tuesday, February 5, 13
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Take this number as reference: running time and pixels number can be modulated upon you performance parameters of you detectors.
by A.Nucciotti Text Tuesday, February 5, 13
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
163Ho in a microclorimeter
163Ho 163Dy* + νe, T1/2 about 4500 1011-1013 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 effjciency .
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
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Er-162(nth,g)Er-163Ho-163 has 480 barn cros.sect (good yield!).
Er-162 have 0.2% natural abundance
Needed enriched Er-162 at level of 20%-40%
Needed pure sample of Er(oxide): not easy!
Other stable isotopes:164, 166, 167, 168 don’t give out long lived radioactive contaminant.
First attempt in 1 MW reactor of 5 mg
Yield: 2x1011 Ho-163/3x1015 Er-162 from CHEMGAS-39% enrichment (10h irradiation in 1MW reactor)
First production has been tested using a calorimeter as external
Si Ir Bi
Drop of Ho-Cl
14 eV FWHM sulla Baseline
Tuesday, February 5, 13
New sample from IsoFlex (USA- RUSSIA)
120 h irradiation
Gamma spectroscopy of sample as received.
First outlook: much more radioactive isotopes then expected from the first sample extrapolation.
Sample origin? this second sample comes from Russia isotope separation
M R Gomes and Courtesy of ITN/IST
G.Pizzigoni Tuesday, February 5, 13
Neutrino mass calorimetric measurements using
163Ho in a microclorimeter Thermo-reduction is needed: mixing with compound the reduce the Ho-
Y5Si3 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)
Y5Si3 allows to trap Oxygen in Y neighboring or gives O2 gas The thermo-reduction will give out Y5-y Hoy Si3 The Y5-x Hox Si3 can be used
As thin film in gold absorber As target for implantation
Low temperature properties under control
M.Galeazzi Tuesday, February 5, 13
Eu lines used as tracker mostly Ge background
Text Tuesday, February 5, 13
fabrication of TES u-cal for measurement of YSi:Ho as detector
Tuesday, February 5, 13
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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
Tuesday, February 5, 13
M R Gomes, Lisboa Tuesday, February 5, 13
Study of effective implantation profile with RBA method Preparation of sample with Ho Er mixture as expected in the final configuration Specific heat measurement between 0.05-300 mK Conclusion: the implantation in gold is a second viable method and need a test on a detector (LNF)
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TES array NASA/GSFC type
163Ho
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.
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Tuesday, February 5, 13
Peter Day (Caltech-JPL) @ MiB U.Lisboa – CFNUL NASA GSFC,U. Wisconsin, NIST Boulder
PTB FBK Trento Italy
Tuesday, February 5, 13
measurements with the present technology of Low Temperature Detectors.
impurities.
also a method of first purification. Further purification can be done at magnetic separator.
tested separately and are both viable absorber for microcalorimeters.
how to put Ho-163 in microcalorimeter arrays.
Tuesday, February 5, 13