S. Capelli

Scintillating double-beta-decay bolometers

We present the results obtained in the development of scintillating double-beta-decay bolometers. Several Mo and Cd based crystals were tested with the bolometric technique. The scintillation light was measured through a second independent bolometer. A 140-g CdWO4 crystal was run in a 417-h live time measurement. Thanks to the scintillation light, the α background is easily discriminated, resulting in zero counts above the 2615-keV γ line of 208Tl. These results, combined with an extreme easy light detector operation, represent the first tangible proof demonstrating the feasibility of this kind of technique.

Characterization of ZnSe scintillating bolometers for Double Beta Decay

Abstract ZnSe scintillating bolometers are good candidates for future Double Beta Decay searches, because of the 82Se high Q-value and thanks to the possibility of alpha background rejection on the basis of the scintillation signal. In this paper we report the characteristics and the anomalies observed in an extensive study of these devices. Among them, an unexpected high emission from alpha particles, accompanied with an unusual pattern of the light vs. heat scatter plot. The perspectives for the application of this kind of detectors to search for the Neutrinoless Double Beta Decay of 82Se are presented.

The programmable front-end readout system for Cuoricino, an array of large mass bolometers

We report on the front-end electronics realized for the readout of the CUORICINO experiments array of 60 large-mass bolometers. The front end consists of a preamplifier and a bias system for the bolometer. A second stage completes the analog circuitry. A significant feature of our design is its capability for in-situ DC characterization of each bolometer as a function of applied bias. The principal front-end operating parameters, including low-noise bias selection, load resistor selection, offset compensation, and gain, are remotely programmable.

Monte Carlo evaluation of the external gamma, neutron and muon induced background sources in the CUORE experiment

CUORE is a 1 ton scale cryogenic experiment aiming at the measurement of the Majorana mass of the electron neutrino. The detector is an array of 988 TeO2 bolometers used for a calorimetric detection of the two electrons emitted in the ββ(0ν) of Te. The sensitivity of the experiment to the lowest Majorana mass is determined by the rate of background events that can mimic a ββ(0ν). In this paper we investigate the contribution of external sources i.e. environmental gammas, neutrons and cosmic ray muons to the CUORE background and show that the shielding setup designed for CUORE guarantees a reduction of this external background down to a level < 10 counts/kgkeVyr at the Q-value, as required by the physical goal of the experiment.

New limit on the neutrinoless betabeta decay of 130Te.

We report the present results of CUORICINO, a search for neutrinoless double-beta (0nu betabeta) decay of 130Te. The detector is an array of 62 TeO2 bolometers with a total active mass of 40.7 kg. The array is cooled by a dilution refrigerator shielded from environmental radioactivity and energetic neutrons, operated at approximately 8 mK in the Gran Sasso Underground Laboratory. No evidence for (0nu betabeta) decay was found and a new lower limit, T(1/2)(0nu) > or = 1.8 x 10(24) yr (90% C.L.) is set, corresponding to [m(nu)] < or = 0.2 to 1.1 eV, depending on the theoretical nuclear matrix elements used in the analysis.

Results from a search for the 0 ν ββ-decay of 130 Te

A detailed description of the CUORICINO 130 Te neutrinoless double-beta (0 νββ) decay experiment is given and recent results are reported. CUORICINO is an array of 62 tellurium oxide (TeO 2 ) bolometers with an active mass of 40.7 kg. It is cooled to ∼8-10 mK by a dilution refrigerator shielded from environmental radioactivity and energetic neutrons. It is running in the Laboratori Nazionali del Gran Sasso (LNGS) in Assergi, Italy. These data represent an exposure of 11.83 kg yr or 91 mole-years of 130 Te. No evidence for 0 νββ-decay was observed and a limit of T 0ν 1/2 ( 130 Te) ≥ 3.0 x 1024 y (90% CL) is set. This corresponds to an upper limit on the effective mass, , between 0.19 and 0.68 eV when analyzed with the many published nuclear structure calculations. In the context of these nuclear models, the values fall within the range corresponding to the claim of evidence of 0 νββ-decay by H. V. Klapdor-Kleingrothaus et al. The experiment continues to acquire data.

Results from a search for the

A detailed description of the CUORICINO 130 Te neutrinoless double-beta (0 νββ) decay experiment is given and recent results are reported. CUORICINO is an array of 62 tellurium oxide (TeO 2 ) bolometers with an active mass of 40.7 kg. It is cooled to ∼8-10 mK by a dilution refrigerator shielded from environmental radioactivity and energetic neutrons. It is running in the Laboratori Nazionali del Gran Sasso (LNGS) in Assergi, Italy. These data represent an exposure of 11.83 kg yr or 91 mole-years of 130 Te. No evidence for 0 νββ-decay was observed and a limit of T 0ν 1/2 ( 130 Te) ≥ 3.0 x 1024 y (90% CL) is set. This corresponds to an upper limit on the effective mass, , between 0.19 and 0.68 eV when analyzed with the many published nuclear structure calculations. In the context of these nuclear models, the values fall within the range corresponding to the claim of evidence of 0 νββ-decay by H. V. Klapdor-Kleingrothaus et al. The experiment continues to acquire data.

0\nu\beta\beta

J. W. Beeman, M. Biassoni , C. Brofferio , C. Bucci, S. Capelli , L. Cardani, M. Carrettoni , M. Clemenza , O. Cremonesi, E. Ferri , A. Giachero, L. Gironi , P. Gorla , C. Gotti , A. Nucciotti , C. Maiano , L. Pattavina, M. Pavan , G. Pessina, S. Pirro , E. Previtali , M. Sisti , and L. Zanotti 3 Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA Dipartimento di Fisica, Università di Milano-Bicocca, Milano I-20126 Italy INFN Sezione di Milano Bicocca, Milano I-20126 Italy INFN Laboratori Nazionali del Gran Sasso, Assergi (L’Aquila) I-67010 Italy Dipartimento di Fisica, Sapienza Università di Roma, and INFNSezione di Roma, Roma I-00185, Italy INFN Sezione di Roma II, Roma I-00133 Italy and Dipartimento di Elettronica e TLC, Università di Firenze, Via S. Marta 3, Firenze I-50125 Italy (Dated: February 3, 2013)

-decay of

The R&D activity performed during the last years proved the potential of ZnSe scintillating bolometers to the search for neutrino-less double beta decay, motivating the realization of the first large-mass experiment based on this technology: CUPID-0. The isotopic enrichment in