Daniele Pergolesi, Institut d’Astrophysique de Paris, Nov 14Daniele Pergolesi, Institut d’Astrophysique de Paris, Nov 14 thth 2005 2005 11

The MARE experiment on direct The MARE experiment on direct measurement of neutrino massmeasurement of neutrino mass

Daniele PergolesiDaniele Pergolesi UNIVERSITY and INFN of Genova UNIVERSITY and INFN of Genova

Daniele Pergolesi, Institut d’Astrophysique de Paris, Nov 14Daniele Pergolesi, Institut d’Astrophysique de Paris, Nov 14 thth 2005 2005 22

MAREMicrocalorimeter Arrays for a Rhenium Experiment

COLLABORATION:

INFN sez. Genova and Università di Genova, Dipartimento di Fisica, ITALY

NASA Goddard Space Flight Center, USA

Universität Heidelberg, Kirchhoff-Institut für Physik, GERMANY

Università dell’Insubria, Dipartimento di Fisica e Matematica, ITALY

INFN sez. Milano and Università di Milano-Bicocca, Dipartimento di Fisica, ITALY

ITC-IRST, Trento, ITALY

University of Wisconsin, Physics Department, USA

+

NIST Boulder USA, Miami University USA, PTB Berlin GERMANY

Daniele Pergolesi, Institut d’Astrophysique de Paris, Nov 14Daniele Pergolesi, Institut d’Astrophysique de Paris, Nov 14 thth 2005 2005 33

Scientific motivations:

What does the oscillations tell us?

- Neutrino has a mass

- neutrino is in a coherent superposition of three different states: e

- atmospheric ∆m232 ≈ 2 10⋅ -3 eV2 (SK + CHOOZ)

- solar ∆m122 ≈ 7 10⋅ -5 eV2 (SNO + KAMland)

- Approx measurment or constraints on the elements of the mixing matrix: |i = Uij |i

What we do not know:

- Mass hierarchy:

- The absolute mass scale

- Neutrino is a Majorana or a Dirac particle?

normal inverted

Degenerate hierarchy when m1 ≈ m2 ≈ m3

Daniele Pergolesi, Institut d’Astrophysique de Paris, Nov 14Daniele Pergolesi, Institut d’Astrophysique de Paris, Nov 14 thth 2005 2005 44

Neutrinoless double beta decay - 0νββ: me< 0.35 eV (Heidelberg—Moscow 76Ge)

me< 0.2÷1.1 eV (CUORICINO 130Te)

me = 0.1÷0.9 eV (Klapdor: : 76Ge reanalysis)

Cosmology: Σmi< 0.42eV (CMB+SDSS+SN)

Single -decay: me< 2.2eV (Troitsk, Mainz electrostatic spectrometer)

All of these techniques are model dependent:

• 0νββ needs to assume that neutrino is a Majorana particle

• In an electrostatic spectrometer the source is outside the detector and the deconvolution from the data of the response function of the spectrometer is complicated (systematic problems with final state corrections, energy loss in the source)

Future perspectives for electrostatic spectrometer: KATRIN me< 0.2eV in 2010.

Direct sub-eV determination (model independent with different systematic) needed!!

Neutrino mass scale determination: Present status

Daniele Pergolesi, Institut d’Astrophysique de Paris, Nov 14Daniele Pergolesi, Institut d’Astrophysique de Paris, Nov 14 thth 2005 2005 55

The so-called direct neutrino mass measurement, or its upper limit determination, can be obtained by means of microcalorimeter with internal source (Re).

Only the neutrino energy escapes the detection and the total decay energy minus the energy carried away by the neutrino is measured. What is effectively measured, is the neutrino energy in the form of a missing energy at the end-point of the -decay spectrum.

The lifetime of the excited molecular or atomic states is negligible with respect to the detector time response (i.e. no loss of energy stored in excited states).

Good knowledge of the detector response function allows the reconstruction of the theoretical spectral shape.

Re is a very efficient absorber for microcalorimeter at the typical working temperature of about 100mK.

Daniele Pergolesi, Institut d’Astrophysique de Paris, Nov 14Daniele Pergolesi, Institut d’Astrophysique de Paris, Nov 14 thth 2005 2005 66

MARE Microcalorimeter Array for a Renium Experiment

Direct measurement of neutrino mass studying the 187Re -decay spectrum

MANU MIBETA

MANU2 MIBETA2

MARE phase1

MARE phase2

Daniele Pergolesi, Institut d’Astrophysique de Paris, Nov 14Daniele Pergolesi, Institut d’Astrophysique de Paris, Nov 14 thth 2005 2005 77

MANU: ResultsMANU: Results

End-point =(2470 ± 1 stat ± 4 sys) eVEnd-point =(2470 ± 1 stat ± 4 sys) eV Half-life = (4.12 ± 0.02stat ± 0.11sys) 10Half-life = (4.12 ± 0.02stat ± 0.11sys) 1010 10 yy

mmnn 2 2 = - 462 = - 462 +579+579 –679 –679 eVeV22/c/c4 4

mmnn < 26 eV/c < 26 eV/c2 2 95% CL, < 19 eV/c 95% CL, < 19 eV/c2 2 90% CL 90% CL

First observation of the Beta First observation of the Beta Environmental Fine Structure (BEFS) Environmental Fine Structure (BEFS)

microcalorimetric measurementof 187Re -decay spectrum

Fine structure of the residual

Daniele Pergolesi, Institut d’Astrophysique de Paris, Nov 14Daniele Pergolesi, Institut d’Astrophysique de Paris, Nov 14 thth 2005 2005 99

Q = 2465.3 0.5 stat 1.6 sys eV

½ = 43.2 0.2 stat 0.1 sys Gy

M2 = -112 207 stat 90 sys eV2

M15.0 eV (90% c.l.)

MIBETAMIBETA:: resultsresults

Daniele Pergolesi, Institut d’Astrophysique de Paris, Nov 14Daniele Pergolesi, Institut d’Astrophysique de Paris, Nov 14 thth 2005 2005 1010

MANU and MIBETA phases II

MARE phase I

Aims: sensitivity range between 1 and 2 eVAims: sensitivity range between 1 and 2 eV

MARE phase1 will provide, for the very first time, the opportunity of checking the results obtained with the electrostatic spectrometer

Daniele Pergolesi, Institut d’Astrophysique de Paris, Nov 14Daniele Pergolesi, Institut d’Astrophysique de Paris, Nov 14 thth 2005 2005 1111

MARE phase1

MIBETA2

Options and perspectives

MIBETA2: MC simulation

1010 events needed to reach the required sensitivity

Daniele Pergolesi, Institut d’Astrophysique de Paris, Nov 14Daniele Pergolesi, Institut d’Astrophysique de Paris, Nov 14 thth 2005 2005 1212

MANU2MANU2 Key Features:Key Features:

• 300 microcalorimeters with rhenium 300 microcalorimeters with rhenium single crystal absorbersingle crystal absorber

• RequiredRequiredE: 5-10 eV FWHM @ 6KeVE: 5-10 eV FWHM @ 6KeV

• TES sensors (Ir/Au – TES sensors (Ir/Au – Al\Ag) Al\Ag) operating at about 100mK operating at about 100mK

• Testing no-SQUID readout electronicsTesting no-SQUID readout electronics

MANU2 statistical sensitivity

MARE phase1

Daniele Pergolesi, Institut d’Astrophysique de Paris, Nov 14Daniele Pergolesi, Institut d’Astrophysique de Paris, Nov 14 thth 2005 2005 1313

First test of MANU2 single pixelFirst test of MANU2 single pixel Ir\Au TES on high purity Si substrate Ir\Au TES on high purity Si substrate

operating at about 80 mK. operating at about 80 mK. Re crystal: (400x470x54) Re crystal: (400x470x54) mm33

Signal amplified (x10) at room T, bandwidth Signal amplified (x10) at room T, bandwidth (1-1000)Hz and read out by DC-SQUID(1-1000)Hz and read out by DC-SQUID

Amplitude 2560mV

rise time 100s (10-90 %)

Pile-up discrim. time 50s

RMS noise 1.2mV

Energy resolution at 6KeV

Daniele Pergolesi, Institut d’Astrophysique de Paris, Nov 14Daniele Pergolesi, Institut d’Astrophysique de Paris, Nov 14 thth 2005 2005 1414

MARE phase2

From MARE phase1 results:

• Scaling up to hundreds of channels

• Optimization of single channel performances

• Study of the sources of systematic uncertainties

• Precise understanding of the Re -decay spectrum (BEFS)

Requirements: neutrino mass Stat. Sens. of 0.2eV (90%C.L.)

New generation detector: faster rise time (order of sec),energy resolution of about 5eV FWHM in the energy range of interest)

TES-MC

MMC?

Read-out electronics: multiplexed SQUID

Very big number of channels (order of 5 104) for Mtot ≈ 1Kg, requires detector modularity

Daniele Pergolesi, Institut d’Astrophysique de Paris, Nov 14Daniele Pergolesi, Institut d’Astrophysique de Paris, Nov 14 thth 2005 2005 1515

MARE phase2

MC simulation of the sensitivity of MARE phase2 (from the Milano Group)

Daniele Pergolesi, Institut d’Astrophysique de Paris, Nov 14Daniele Pergolesi, Institut d’Astrophysique de Paris, Nov 14 thth 2005 2005 1616

1990 1995 2000 2005 2010 2015

1990 1995 2000 2005 2010 2015

Spettrometri

CalorimetriSandro Vitale

1985187Re

20 eV 2 eV 0.2 eV

20 eV

2 eV 0.2 eV

KATRIN v.s. MARE in sub-eV KATRIN v.s. MARE in sub-eV mass search mass search

MANU

MIBETA

26 eV

15 eV

MARE

MAINZ

TROITZK

spettrometrielettrostatici

KATRIN

2.2 eV

2.2 eVspettrometrimagnetici

20-10 eV

From A. Giuliani, Insubria University

MARE phase2 will be the only available way to confirm or disprove KATRIN results