100 research outputs found
Determination of the Boltzmann constant k from the speed of sound in helium gas at the triple point of water
partially_open6The Boltzmann constant k has been determined from a measurement of the speed of sound in helium gas in a quasi-spherical resonator (volume 0.5 l) maintained at a temperature close to the triple point of water (273.16 K). The acoustic velocity c is deduced from measured acoustic resonance frequencies and the dimensions of the quasi-sphere, the latter being obtained via simultaneous microwave resonance. Values of c are extrapolated to the zero pressure limit of ideal gas behaviour. We find J⋅K−1, a result consistent with previous measurements in our group and elsewhere. The value for k, which has a relative standard uncertainty of 1.02 ppm, lies 0.02 ppm below that of the CODATA 2010 adjustment.mixedPitre, L; Risegari, L; Sparasci, F; Plimmer, M D; Himbert, M E; Giuliano Albo, P APitre, L; Risegari, L; Sparasci, F; Plimmer, M D; Himbert, M E; Giuliano Albo, P
The magnetic properties of Hf and Hf in the strong coupling deformed model
This paper reports NMR measurements of the magnetic dipole moments of two
high-K isomers, the 37/2, 51.4 m, 2740 keV state in Hf and the
8, 5.5 h, 1142 keV state in Hf by the method of on-line nuclear
orientation. Also included are results on the angular distributions of gamma
transitions in the decay of the Hf isotope. These yield high
precision E2/M1 multipole mixing ratios for transitions in bands built on the
23/2, 1.1 s, isomer at 1315 keV and on the 9/2, 0.663 ns, isomer at 321
keV. The new results are discussed in the light of the recently reported
finding of systematic dependence of the behavior of the g parameter
upon the quasi-proton and quasi-neutron make up of high-K isomeric states in
this region.Comment: 9 pages, 9 figures, accepted for publication in Physical Review
A New Limit on the Neutrinoless DBD of 130Te
We report the present results of CUORICINO a cryogenic experiment on
neutrinoless double beta decay (DBD) of 130Te consisting of an array of 62
crystals of TeO2 with a total active mass of 40.7 kg. The array is framed
inside of a dilution refrigerator, heavily shielded against environmental
radioactivity and high-energy neutrons, and operated at a temperature of ~8 mK
in the Gran Sasso Underground Laboratory. Temperature pulses induced by
particle interacting in the crystals are recorded and measured by means of
Neutron Transmutation Doped thermistors. The gain of each bolometer is
stabilized with voltage pulses developed by a high stability pulse generator
across heater resistors put in thermal contact with the absorber.
The calibration is performed by means of two thoriated wires routinely
inserted in the set-up. No evidence for a peak indicating neutrinoless DBD of
130Te is detected and a 90% C.L. lower limit of 1.8E24 years is set for the
lifetime of this process. Taking largely into account the uncertainties in the
theoretical values of nuclear matrix elements, this implies an upper boud on
the effective mass of the electron neutrino ranging from 0.2 to 1.1 eV. This
sensitivity is similar to those of the 76Ge experiments.Comment: 4 pages, 2 figure
Quadrupole moment of the 6− isomeric state in 66Cu: Interplay between different nuclear deformation driving forces
AbstractWe have measured the spectroscopic quadrupole moment of the 6− isomeric state in 66Cu to be |Qs|=18.6(12) efm2. This state results from a weak coupling of the πp3/2 and the νg9/2 orbitals, which lead to sizable deformation at oblate and prolate shapes, correspondingly, in the 68Ni region. The interplay between these two different deformation-driving orbitals is observed at N=37 for the 6− state resulting in a most probable oblate shape
Double-beta decay of Te to the first 0 excited state of Xe with CUORICINO
The CUORICINO experiment was an array of 62 TeO single-crystal
bolometers with a total Te mass of kg. The experiment finished
in 2008 after more than 3 years of active operating time. Searches for both
and double-beta decay to the first excited state in
Xe were performed by studying different coincidence scenarios. The
analysis was based on data representing a total exposure of
N(Te)t=y. No evidence for a signal was
found. The resulting lower limits on the half lives are y (90% C.L.), and
y (90%
C.L.).Comment: 6 pages, 4 figure
Experimental study of high energy electron interactions in a superconducting aluminum alloy resonant bar
Peak amplitude measurements of the fundamental mode of oscillation of a
suspended aluminum alloy bar hit by an electron beam show that the amplitude is
enhanced by a factor ~3.5 when the material is in the superconducting state.
This result is consistent with the cosmic ray observations made by the resonant
gravitational wave detector NAUTILUS, made of the same alloy, when operated in
the superconducting state. A comparison of the experimental data with the
predictions of the model describing the underlying physical process is also
presented
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Search for double-β decay of 130Te to the first 0+ excited state of 130Xe with the CUORICINO experiment bolometer array
The CUORICINO experiment was an array of 62 TeO2 single-crystal bolometers with a total 130Te mass of 11.3kg. The experiment finished in 2008 after more than 3 yr of active operating time. Searches for both 0ν and 2ν double-β decay to the first excited 0+ state in 130Xe were performed by studying different coincidence scenarios. The analysis was based on data representing a total exposure of N(130Te)⋅t=9.5×1025yr. No evidence for a signal was found. The resulting lower limits on the half-lives are T2ν12(130Te→130Xe∗)\u3e1.3×1023yr (90% C.L.), and T0ν12(130Te→130Xe∗)\u3e9.4×1023yr (90% CL)
New Cuoricino Results and Status of CUORE
CUORICINO is an array of 62 TeO2 bolometers with a total mass of 40.7 kg (11.2 kg of 130Te), operated at about 10 mK to search for ββ(0ν) of 130Te. The detectors are organized as a 14-story tower and intended as a slightly modified version of one of the 19 towers of the CUORE project, a proposed tightly packed array of 988 TeO2 bolometers (741 kg of total mass of TeO2) for ultralow-background searches on neutrinoless double-beta decay, cold dark matter, solar axions, and rare nuclear decays. Started in April 2003 at the Laboratori Nazionali del Gran Sasso (LNGS), CUORICINO data taking was stopped in November 2003 to repair the readout wiring system of the 62 bolometers. Restarted in spring 2004, CUORICINO is presently the most sensitive running experiment on neutrinoless double-beta decay. No evidence for ββ(0ν) decay has been found so far and a new lower limit, T 1 2/0ν ≥ 1.8 × 1024 yr (90% C.L.), is set, corresponding to 〈m ν〉 ≤ 0.2–1.1 eV, depending on the theoretical nuclear matrix elements used in the analysis. Detector performance, operational procedures, and background analysis results are reviewed. The expected performance and sensitivity of CUORE is also discussed
New CUORICINO Results On the Way to CUORE
CUORE is a 0.75 ton experiment to search for neutrinoless double beta decay of Te130 using 988 TeO2 bolometers. It aims at reaching a sensitivity on the effective neutrino mass of the order of few tens of meV. CUORICINO, a single CUORE tower running since 2003, plays an important role as a stand alone experiment and for developing the future CUORE setup. Present results already achieved and studies that are underway are here presented and discussed
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