L. Foggetta

Surface-sensitive macrobolometers for the identification of external charged particles

We report the performance of two prototype TeO2 macrobolometers, operated at ∼25mK, able to identify events due to energy deposited at the detector surface. This capability is obtained by thermally coupling thin Ge active layers to the main energy absorber of the bolometer, and is demonstrated by irradiating the detectors with α particles. The temperature variations of the main absorber and of the active layer are measured independently with doped Ge thermistors. These results show clearly that an intrinsic limitation of monolithic low temperature calorimeters, e.g., the impossibility to give information about event position, can be efficiently overcome using composite structures.

AGILE View of TGFs

The AGILE Satellite [8] [9], launched the 23rd April 2007, is an italian mission devoted to high energy gamma‐ray astrophysics in the 30 MeV–50 GeV range, with a window in the hard‐X domain 18–60 keV. One of the on‐board detectors, the Mini‐Calorimeter (MCAL), was also designed to work as all sky transient monitor in the energy range 0.33–100 MeV. Though the main purpose of MCAL is the detection of cosmological Gamma‐Ray‐Bursts (GRB), MCAL detected transient events with a very brief duration, few msec, that does not match timing and spectral features of known cosmic GRB. These events more likely agree with the features of typical Terrestrial Gamma‐Ray Flashes as described in the literature and previously detected by the BATSE instrument onboard the Compton Gamma Ray Observatory and the RHESSI satellite. The characteristics of the detected TGF candidate events, as well as their geographical distribution will be presented and discussed.

CUORE EXPERIMENT: THE SEARCH FOR NEUTRINOLESS DOUBLE BETA DECAY

The main purpose of the Cryogenic Underground Observatory for Rare Events (CUORE) experiment is the search for the Neutrinoless Double Beta Decay (0νDBD) of 130Te reaching a sensitivity on Majorana mass better than 50 meV. Cuoricino represents not only the first stage of CUORE, but also the most massive 0νDBD experiment presently running. Present results and future planning of these experiments will be described in the paper.

An active-shield method for the reduction of surface contamination in CUORE

The main goal of the CUORE experiment is to search for the neutrinoless double beta decay of 130Te. As it is a rare nuclear decay, the sensitivity of the experiment strongly depends on the background level in the transition energy region. In this paper we describe the R&D work performed to develop an active method for the reduction of radioactive background in CUORE. The idea is to reject events originated by surface contamination in large mass bolometric detectors by using bolometers sensitive to surface events. Results obtained with the first prototypes and tests made with large mass surface sensitive bolometers will be reported.

The AGILE Mission and Gamma‐Ray Bursts

The AGILE Mission will explore the gamma‐ray Universe with a very innovative instrument combining for the first time a gamma‐ray imager and a hard X‐ray imager. AGILE will be operational at the beginning of 2007 and it will provide crucial data for the study of Active Galactic Nuclei, Gamma‐Ray Bursts, unidentified gamma‐ray sources, Galactic compact objects, supernova remnants, TeV sources, and fundamental physics by microsecond timing. The AGILE instrument is designed to simultaneously detect and image photons in the 30 MeV – 50 GeV and 15 – 45 keV energy bands with excellent imaging and timing capabilities, and a large field of view covering ∼ 1/5 of the entire sky at energies above 30 MeV. A CsI calorimeter is capable of GRB triggering in the energy band 0.3–50 MeV. The broadband detection of GRBs and the study of implications for particle acceleration and high energy emission are primary goals of the mission. AGILE can image GRBs with 2–3 arcminute error boxes in the hard X‐ray range, and provide bro...

Search for β+/EC double beta decay of120Te

We present a search for beta plus/EC double beta decay of 120Te performed with the CUORICINO experiment, an array of TeO2 cryogenic bolometers. After collecting 0.0573 kg y of 120Te, we see no evidence of a signal and therefore set the following limits on the half-life: T1/2 (0nu) > 1.9 10^{21} y at 90% C.L. for the 0 neutrino mode and T1/2 (2nu) > 7.6 10^{19} y at 90% C.L. for the two neutrino mode. These results improve the existing limits by almost three orders of magnitude (four in the case of 0 neutrino mode).

Search for β+/EC double beta decay of 120Te

We present a search for beta plus/EC double beta decay of 120Te performed with the CUORICINO experiment, an array of TeO2 cryogenic bolometers. After collecting 0.0573 kg y of 120Te, we see no evidence of a signal and therefore set the following limits on the half-life: T1/2 (0nu) > 1.9 10^{21} y at 90% C.L. for the 0 neutrino mode and T1/2 (2nu) > 7.6 10^{19} y at 90% C.L. for the two neutrino mode. These results improve the existing limits by almost three orders of magnitude (four in the case of 0 neutrino mode).

Search for beta(+)/EC double beta decay of Te-120

We present a search for beta plus/EC double beta decay of 120Te performed with the CUORICINO experiment, an array of TeO2 cryogenic bolometers. After collecting 0.0573 kg y of 120Te, we see no evidence of a signal and therefore set the following limits on the half-life: T1/2 (0nu) > 1.9 10^{21} y at 90% C.L. for the 0 neutrino mode and T1/2 (2nu) > 7.6 10^{19} y at 90% C.L. for the two neutrino mode. These results improve the existing limits by almost three orders of magnitude (four in the case of 0 neutrino mode).

GRB 070724B: the first Gamma Ray Burst localized by SuperAGILE

GRB070724B is the first Gamma Ray Burst localized by the SuperAGILE instrument aboard the AGILE space mission. The SuperAGILE localization has been confirmed after the after‐glow observation by the XRT aboard the Swift satellite. No significant gamma ray emission above 50 MeV has been detected for this GRB. In this paper we describe the SuperAGILE capabilities in detecting Gamma Ray Burst and the AGILE observation of GRB 070724B.

Passive shielding in CUORE

The nature of neutrino mass is one of the friontier problems of fundamental physics. Neutrinoless Double Beta Decay (0νDBD) is a powerful tool to investigate the mass hierarchy and possible extensions of the Standard Model. CUORE is a 1‐Ton next generation experiment, made of 1000 Te bolometers, aiming at reaching a background of 0.01 (possibly 0.001) counts keV−1kg−1y−1 and therefore a mass sensitivity of few tens of meV The background contribution due to environmental neutrons, muon‐induced neutrons in the shieldings and external gamma is discussed.