1 / 29

MARE: Status and Perspectives

This presentation discusses the status and future prospects of the MARE experiment, which focuses on high precision calorimetric measurements using single crystal detectors. The experiment aims to achieve a sensitivity of 0.2 eV and has challenges related to array-based measurements. Various technologies, including Re-TES arrays and AgReO-Si arrays, are being explored. The presentation also discusses developments in detector prototypes and the potential use of metallic magnetic calorimeters. The use of micro-fabricated x-ray detectors and optimization of MMCs with superconducting rhenium absorbers are also highlighted.

mdurrant
Download Presentation

MARE: Status and Perspectives

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. MARE: Status and Perspectives Flavio Gatti University and INFN of Genoa on behalf of the MARE Collaboration NUMASS2010 INT Seattle, Feb. 9, 2010

  2. MARE: a LTD experiment in R&D

  3. Re Single Crystal (99,999%) C~pJ @ 0.1K → mm3 size crystals → arrays of detectors Rhenium (63% 187Re) 15 crystals of this type are needed for 0.2 eV sensitivity experiment

  4. Thermistor Ir-Au TES on Si Electrical & Heat link Al -1% Si wires 15 μm diam., 1mm length Re Crystal surfaces cleaned to optical level annealed at 1300ºC in UHV Calorimetric spectroscopy FALL TIME (Depends on C, G, Bias Power) Thermal contact High purity epoxy RISE TIME (Depends on internal Parameter Absorber-TES)

  5. Statistics → 1014 Unresolved pileup → 10-7 Energy Resolution → 1 eV Energy calibration → 10 -4 Background → hope negligible! BEFS → know at very precise level Possible unknown systematics → under continuous investigation (we are at the frontiers…) MARE measurement challenges

  6. Sensitivity and uncertainties of array based experiment A.Nucciotti

  7. MARE-I: assessment of methods and technology • The full MARE experiment is still in the R&D phase and multiple options are being evaluated. • Mainly: 2 options for b-isotopes, 2 option for the detector technology ISOTOPE TECHNOLOGY 187Re 163Ho TES MagCal

  8. Current Developments • Re-TES array:Genoa-Miami • AgReO –Si array:Milan-Wisconsin-Goddard • MUX Readout:PTB-Genoa • Kinetic Inductance Sensors: Insubria-IRSTTrento • Magnetic Calorimeter:Heidelberg • GEANT simulation and data Analysis:Florida-Miami • MC modeling for experiment design:Milan • Ho-163:Genoa-Lisboa/ISOLDE CERN-Goddard • Production and study of low Q E.C. isotopes:GSI

  9. Re-TES detector prototypes (Genoa) • Improve detector pulse rise-time to usec; • Improve energy resolution from 10 eV (presently) to few eV; • Large arrays (K-pixels) in order to achieve 104 -105 detectors in small volume; • Provide an array design fully compatible with the requirements of a high precision experiment (high reproducibility, stability, fully energy calibrated,…); • Multiplexed read-out with large bandwidth (> 300 KHz) per channel; Re crystal Re-crystal on epoxy-post / Ir-TES / SiN-membrane Al leads for TES

  10. 600 µm 300 mm Si support Pilot experiment of 72 detector array (Milan) • Single crystal of silver perrhenate (AgReO4) as absorber • mass ~ 500 mg per pixel (Ab~ 0.3 decay/sec) • regular shape (600x600x250 mm3) • low heat capacity due to Debye law • 6x6 array of Si thermistors (NASA/GSFC) • pixel: 300x300x1.5 mm3 • high energy resolution • developed for X-ray spectroscopy

  11. M T Metallic MagneticCalorimeters temperature rise upon absorption: recovery time: paramagnetic sensor: Au:Er • Operation at low temperatures (T<100mK) • small heat capacity • large temperature change • small thermal noise • Main differences to resistive calorimeters • no dissipation in the sensor • no galvanic contact to the sensor signal size:

  12. University of HeidelbergKirchhoff- Institute for Physics • Planar sensors on meander shaped pickup coils • Energy resolution DEFWHM = 2.8 eV @ 6 keV DEFWHM= 2.65 eV @ 0 keV baseline 55Mn  Expected energy resolution for next produced detectors <2 eV

  13. Micro-fabricated x-ray detectors • Planar sensors on meander shaped pickup coils • Energy resolution • Rise time rise time: 90 ns @ 30 mK as expected from Korringa-constant for Er in Au

  14. MMC for Neutrino Massexperiments MMCs for Neutrino Mass Experiments • Optimization of MMCs with superconducting rhenium absorber • - minimization of the rise-time • - investigation of energy down-conversion in superconducting absorbers • - investigating the energy resolution achievable with superconducting absorber • Improvements in therise-time: • manualyassembleddetector ~1ms • sensordepositeddirectly on the Re • absorber ~20s • Achievablerise-time ≤1s A B

  15. MMC for Neutrino Massexperiments MMCs for Neutrino Mass Experiments • Optimization of MMCs with superconducting rhenium absorber • - minimization of the rise-time • - investigation of energy down-conversion in superconducting absorbers • - investigating the energy resolution achievable with superconducting absorber • Calorimetric investigation of new candidates for the neutrino mass direct • measurements by electron capture decay • - 163Ho, 157Tb, 194Hg, 202Hg • - Development of micro-structuredMMCs for ion implantation at ISOLDE • - First detector with implanted 163Ho ready to run

  16. Genoa-PTB development on MUX readout Enhanced Bandwidth requirement respect to X- ray det. readout PTB SQUID under test at Genoa FDM readout scheme under study at Genoa

  17. A second isotope for neutrino mass calorimetric measurements: 163Ho • We have already (10 year ago) performed some test experiment with Ho-163 (F.Gatti, etal.1997) • 163Ho 163Dy* + ne • 163Dy* decays via Coster-Kronig transition nS, nP1/2 • Breit Wigner M,N,O lines have an end-point at the Q value finite neutrino mass causes a kink at the end-point similarly to beta spectra of 187-Re. • The major issue has been the preparation of the absorbers and the overall detector performance that was unsatisfactory due to the not uniform absorber.

  18. Previous test • In the past we made a tentative experiment to verify the feasibility of a measurements • Ho-163 Cl solution from ISOLDE (E Laesgaard) after a tentative made by INR-Moscow (purification failed) • Many effort for production of electroplated tin foils from organic solution at high voltage • Final result was an admixture of fine salt grain onto tin matrix •  not satisfactory E resolution

  19. But 163Ho is very attractive • Advantages: • tunable source activity independent form the absorber masses • Minimization of the absorber mass to the minimum required by the full absorption of the energy cascade  resolution less dependent from the activity • Rise-time much less of 10 us for SiN suspended detector • Higher Counting rate per detector 102 c/s • Self calibrating experiment • Easiest way to reach higher count rate with presently better performing detectors • Implantation tests have been done at ISOLDE (CERN) as product of spallation of Ta target by energetic proton and magnetic selection • First sample contains high level of radioactive impurities • Defined an alternative solution: neutron activation of enriched 162 Er , chemical processing to achieve metallic state, implantation at ISOLDE or LISBOA facility

  20. 163Ho sensitivity • With 2eV detectors (X-ray type) a great step forward in overall sensitivity and detector integration for neutrino mass should be achieved • 187-Re and 163-Ho should provide very low systematic measurement Negligible pile-up

  21. TES array from NASA/GSFC Ho-163 in Goddard Array 163Ho

  22. 163Ho studies • Study of the B.-W. shape far from the maximum and intrinsic line-width, other possible systematics • Simulation under way for simulating sensitivity in realistic condition including the pile-up and the uncertainties on Q value • A high spectral resolution measurement is needed to fix the Q value and other decay parameters. signal Where Q is located? Pile-up

  23. GEANT simulation of whole experiment (Miami-Florida) Unidentified pileup Effect of the decay position in the absorber Efficiency and systematics of the analysis tools Background events originating from radioactive decays in the surrounding cryostat material (also activated by cosmics) 8x108 events 1 mg detector

  24. Summary • MARE-I developments are going to the end • An array of 72 channel is starting taking data taking for testing multiple detector experiment • Study for detector-abosber coupling for Re or Ho are under way and have define the strategy • Detectors with 1-2 eV energy resolution and 0.1 us time resolution are becoming available • Electronics, Simulation, Data Analysis have defined the roadmap • Technology almost ready and but need to be fully exploited and scaled to high detector multiplicity. • In the next 1-2years a decision on the isotope and detector technology should be made and a prototype for MARE II detector built. • MARE-II is a challenging experiment, but feasible. • Full development could start immediately after that (if funding is available both in the US and Europe) • We are more confident that MARE will provide fully complementary results to KATRIN

  25. Backup Slides

  26. 187-Re decay in a crystal: case of Rhenium Metal. • Initial and final states are in the crystal • The spectrum end-point energy is lower than the one of isolated isotope. • Eendpoint=(Q-mec2)-(ef+EFermi)-DBlattice where • EFermi =11.2 eV, • Work function f =5.1 eV • Crystal binding energy Blattice = 16.9 eV • Change of binding from Re->Os DBlattice =2.7% Blattice

  27. 187-Re decay in a crystal: case of Rhenium Metal. • 75 Re [Xe] 4f14 5d5 6s2, Etot= -429402.3 eV • 76 Os+   [Xe] 4f14 5d6 6s1, Etot= -443164.5 eV • 76 Os   [Xe] 4f14 5d6 6s2, Etot=-443172.8 eV • DBcoul = -13.7 keV ! • the bare 187-Re cannot undergo continuum b-decay. Bound state decay of 187Re75+ has been observed in storage ring having 32 y half life and 63KeV Q value • During the decay the beta particle pass through the atom. The electron may not have the time to rearrange the electrons, the difference of atomic binding energy Re-Os+ is very close to the binding energy difference of the initial end final atomic state • Being the energy of the final state Os+ after the decay almost the one of the ground state of Os+, high excited state of the final atom are very unlikely • Further, due to the very similar atomic wave-function the probability of a transition toward an excited state is very small being Os* eigenstate orthogonal to the one of Re. A first evaluation of this probability is 7x10-5.

  28. 187-Re decay in a crystal: case of Rhenium Metal. • Recoil energy at level of few meV respect to several eV per dislocations; recoil contribute directly to the generation of phonon of elastic branch. • Recoil free beta decay (not yet observed) but extending Mossbauer and tacking into account the so small recoil effect, this should be negligible. • Shake off probability at 1% level only for N and O shells, that can emits photons of 50 eV (avg) or Auger electron. They are fully absorbed in hundreds of Ang. • Inner Bremsstrahlung: same Q value but larger penetration depth, however at um level • ExternalBremsstrahlung: can be fully contained as before • Collective excitation: based on long living quasi-particle states

  29. Low Temperature Magnetic Calorimeters for Neutrino Mass Direct Measurement L. Gastaldo, J.P. Porst, F. von Seggern, A. Kirsch, P. Ranitzsch, A. Fleischmannand C. Enss University of Heidelberg Kirchhoff- Institute for Physics

More Related