-
P. Belli,
R. Bernabei,
S.V. Budakovsky,
F. Cappella,
R. Cerulli,
F.A. Danevich, S. d'Angelo,
A. Incicchitti,
M. Laubenstein,
D.V. Poda,
O.G. Polischuk,
V.I. Tretyak
[show abstract]
[hide abstract]
ABSTRACT: The radioactive contamination of two 26 g samples of low background lithium iodide crystal scintillators doped by europium and enriched in 7Li to 99.9% (7LiI(Eu)) has been investigated by scintillation method at the sea level, and by ultra-low background HPGe γ spectrometry deep underground. No radioactive contamination was detected. In particular, the contamination of the crystal scintillators by 226Ra and 228Th does not exceed 1 mBq/kg, and the activity of 40K is less than 0.5 Bq/kg.
Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 03/2013; 704:40–43. · 1.21 Impact Factor
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D. V. Poda,
A. S. Barabash,
P. Belli,
R. Bernabei,
R. S. Boiko,
V. B. Brudanin,
F. Cappella,
V. Caracciolo,
S. Castellano,
R. Cerulli, [......],
S. Nisi,
R. B. Podviyanuk,
O. G. Polischuk,
A. P. Shcherban,
V. N. Shlegel,
D. A. Solopikhin,
V. I. Tretyak,
V. I. Umatov,
Ya. V. Vasiliev,
V. D. Virich
[show abstract]
[hide abstract]
ABSTRACT: Cadmium tungstate crystal scintillators enriched in 106Cd and 116Cd were
developed. The produced scintillators exhibit good optical and scintillation
properties, and a low level of radioactive contamination. Experiments to search
for double beta decay of 106Cd and 116Cd are in progress at the Gran Sasso
National Laboratories of the INFN (Italy). Prospects to further improve the
radiopurity of the detectors by recrystallization are discussed.
Radiation Measurements 03/2013; · 1.18 Impact Factor
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P. Belli,
R. Bernabei,
F. Cappella,
R. Cerulli,
F. A. Danevich, S. d'Angelo,
A. Incicchitti,
G. P. Kovtun,
N. G. Kovtun,
M. Laubenstein,
D. V. Poda,
O. G. Polischuk,
A. P. Shcherban,
D. A. Solopikhin,
J. Suhonen,
V. I. Tretyak
[show abstract]
[hide abstract]
ABSTRACT: An experiment to search for double beta decay processes in 96Ru and 104Ru,
which are accompanied by gamma rays, has been realized in the underground Gran
Sasso National Laboratories of the I.N.F.N. (Italy). Ruthenium samples with
masses of about (0.5-0.7) kg were measured with the help of ultra-low
background high purity Ge gamma ray spectrometry. After 2162 h of data taking
the samples were deeply purified to reduce the internal contamination of 40K.
The last part of the data has been accumulated over 5479 h. New improved half
life limits on 2\beta+/\epsilon \beta+/2\epsilon\ processes in 96Ru have been
established on the level of 10^{20} yr, in particular for decays to the ground
state of 96Mo: T1/2(2\nu 2\beta+) > 1.4 10^{20} yr, T1/2(2\nu \epsilon\beta+) >
8.0 10^{19} yr and T1/2(0\nu 2K) > 1.0 10^{21} yr (all limits are at 90% C.L.).
The resonant neutrinoless double electron captures to the 2700.2 keV and 2712.7
keV excited states of 96Mo are restricted as: T1/2(0\nu KL) > 2.0 10^{20} yr
and T1/2(0\nu 2L) > 3.6 10^{20} yr, respectively. Various two neutrino and
neutrinoless 2\beta\ half lives of 96Ru have been estimated in the framework of
the QRPA approach. In addition, the T1/2 limit for 0\nu 2\beta- transitions of
104Ru to the first excited state of 104Pd has been set as > 6.5 10^{20} yr.
Physical Review C 02/2013; 87(3):034607. · 3.31 Impact Factor
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F. Cappella,
R. Bernabei,
P. Belli,
V. Caracciolo,
R. Cerulli, S. d'Angelo,
A. Di Marco,
A. Incicchitti,
F.A. Danevich,
D.V. Poda,
V.I. Tretyak
[show abstract]
[hide abstract]
ABSTRACT: In the anisotropic scintillators the light output and the pulse shape for heavy particles (p, α, nuclear recoils) depend on the direction with respect to the crystal axes; the response to γ/β radiation is isotropic instead. This feature offers the possibility to study the directionality approach, which is applicable in the particular case of those Dark Matter candidate particles inducing just nuclear recoils. Among the anisotropic scintillators, the ZnWO4 has unique features, which make it an excellent candidate for this type of research, and there is still plenty of room for the improvement of its performances. In this paper the possibility of a low background pioneer experiment (named ADAMO—Anisotropic detectors for DArk Matter Observation) to exploit deep underground the directionality approach by using anisotropic ZnWO4 scintillators is discussed.
European Physical Journal C 01/2013; 73:2276. · 3.63 Impact Factor
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P. Belli,
R. Bernabei,
F. Cappella,
R. Cerulli,
F. A. Danevich, S. d'Angelo,
A. Di Marco,
A. Incicchitti,
G. P. Kovtun,
N. G. Kovtun,
M. Laubenstein,
D. V. Poda,
O. G. Polischuk,
A. P. Shcherban,
V. I. Tretyak
[show abstract]
[hide abstract]
ABSTRACT: A search for double-beta decay of osmium has been realized for the first time
with the help of an ultra-low background HPGe gamma detector at the underground
Gran Sasso National Laboratories of the INFN (Italy). After 2741 h of data
taking with a 173 g ultra-pure osmium sample limits on double-beta processes in
184Os have been established at the level of T_{1/2} about 10^{14}-10^{17} yr.
Possible resonant double-electron captures in 184Os were searched for with a
sensitivity T_{1/2} about 10^{16} yr. A half-life limit T_{1/2} > 5.3 10^{19}
yr was set for the double-beta decay of 192Os to the first excited level of
192Pt. The radiopurity of the osmium sample has been investigated and
radionuclides 137Cs, 185Os and 207Bi were detected in the sample, while
activities of 40K, 60Co, 226Ra and 232Th were limited at the mBq/kg level.
European Physical Journal A 01/2013; 49:24. · 2.19 Impact Factor
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P. Belli,
R. Bernabei,
R. S. Boiko,
V. B. Brudanin,
F. Cappella,
V. Caracciolo,
R. Cerulli,
D. M. Chernyak,
F. A. Danevich, S. d'Angelo, [......],
D. Prosperi,
A. P. Shcherban,
V. N. Shlegel,
D. A. Solopikhin,
Yu. G. Stenin,
J. Suhonen,
A. V. Tolmachev,
V. I. Tretyak,
Ya. V. Vasiliev,
R. P. Yavetskiy
[show abstract]
[hide abstract]
ABSTRACT: Several experiments were performed during last years at underground (3600 m
w.e.) Laboratori Nazionali del Gran Sasso (LNGS) of the INFN (Italy) to search
for resonant 2$\varepsilon0\nu$ captures in 96Ru, 106Cd, 136Ce, 156Dy, 158Dy,
180W, 184Os, 190Pt with the help of HP Ge semiconductor detectors, and ZnWO4
and 106CdWO4 crystal scintillators. No evidence for r-2$\varepsilon0\nu$ decays
was found, and only T_{1/2} limits were established in the range of
10^{14}-10^{21} yr.
Journal of Physics Conference Series 07/2012; 375:042024.
-
[show abstract]
[hide abstract]
ABSTRACT: A search for the double beta decay of zinc and tungsten isotopes has been
performed with the help of radiopure ZnWO4 crystal scintillators (0.1-0.7 kg)
at the Gran Sasso National Laboratories of the INFN. The total exposure of the
low background measurements is 0.529 kg yr. New improved half-life limits on
the double beta decay modes of 64Zn, 70Zn, 180W, and 186W have been established
at the level of 10^{18}-10^{21} yr. In particular, limits on double electron
capture and electron capture with positron emission in 64Zn have been set:
T_{1/2}(2\nu 2K) > 1.1 10^{19} yr, T_{1/2} (0\nu 2\epsilon) > 3.2 10^{20} yr,
T_{1/2} (2\nu \epsilon \beta^+) > 9.4 10^{20} yr, and T_{1/2} (0\nu \epsilon
\beta^+) > 8.5 10^{20} yr, all at 90% C.L. Resonant neutrinoless double
electron capture in 180W has been restricted on the level of T_{1/2} (0\nu
2\epsilon) > 1.3 10^{18} yr. A new half-life limit on alpha transition of 183W
to the metastable excited level 1/2^- 375 keV of 179Hf has been established:
T_{1/2} > 6.7 10^{20} yr.
Journal of Physics G Nuclear and Particle Physics 10/2011; 38(11):115107. · 4.18 Impact Factor
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P. Belli,
R. Bernabei,
F. Cappella,
R. Cerulli,
F. A. Danevich, S D'Angelo,
M. L. Di Vacri,
A. Incicchitti,
M. Laubenstein,
S. S. Nagorny,
S. Nisi,
A.V. Tolmachev,
V. I. Tretyak,
R.P. Yavetskiy
[show abstract]
[hide abstract]
ABSTRACT: A search for double $\beta$ decay of dysprosium was realized for the first
time with the help of an ultra low-background HP Ge $\gamma$ detector. After
2512 h of data taking with a 322 g sample of dysprosium oxide limits on double
beta processes in $^{156}$Dy and $^{158}$Dy have been established on the level
of $T_{1/2}\geq 10^{14}-10^{16}$ yr. Possible resonant double electron captures
in $^{156}$Dy and $^{158}$Dy were restricted on a similar level. As a
by-product of the experiment we have measured the radioactive contamination of
the Dy$_2$O$_3$ sample and set limits on the $\alpha$ decay of dysprosium
isotopes to the excited levels of daughter nuclei as $T_{1/2}\geq 10^{15} -
10^{17}$ yr.
03/2011;
-
P. Belli,
R. Bernabei,
F. Cappella,
R. Cerulli,
F. A. Danevich,
A. M. Dubovik, S D'Angelo,
E. N. Galashov,
B. V. Grinyov,
A. Incicchitti, [......],
F. Nozzoli,
D. V. Poda,
R. B. Podviyanuk,
O. G. Polischuk,
D. Prosperi,
V. N. Shlegel,
V. I. Tretyak,
I. A. Tupitsyna,
Ya. V. Vasiliev,
Yu. Ya. Vostretsov
[show abstract]
[hide abstract]
ABSTRACT: The radioactive contamination of ZnWO4 crystal scintillators has been
measured deep underground at the Gran Sasso National Laboratory (LNGS) of the
INFN in Italy with a total exposure 3197 kg x h. Monte Carlo simulation,
time-amplitude and pulse-shape analyses of the data have been applied to
estimate the radioactive contamination of the ZnWO4 samples. One of the ZnWO4
crystals has also been tested by ultra-low background gamma spectrometry. The
radioactive contaminations of the ZnWO4 samples do not exceed 0.002 -- 0.8
mBq/kg (depending on the radionuclide), the total alpha activity is in the
range: 0.2 - 2 mBq/kg. Particular radioactivity, beta active 65Zn and alpha
active 180W, has been detected. The effect of the re-crystallization on the
radiopurity of the ZnWO4 crystal has been studied. The radioactive
contamination of samples of the ceramic details of the set-ups used in the
crystals growth has been checked by low background gamma spectrometry. A
project scheme on further improvement of the radiopurity level of the ZnWO4
crystal scintillators is briefly addressed.
Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 01/2011; 626–627:31–38. · 1.21 Impact Factor
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P Belli,
R Bernabei,
R S Boiko,
F Cappella,
R Cerulli,
F A Danevich, S d'Angelo,
A Incicchitti,
V V Kobychev,
B N Kropivyansky, [......],
P G Nagornyi,
S S Nagorny,
S Nisi,
F Nozzoli,
D V Poda,
D Prosperi,
O G Polischuk,
V I Tretyak,
I M Vyshnevskyi,
S S Yurchenko
[show abstract]
[hide abstract]
ABSTRACT: Sample of 100MoO3 with molybdenum enriched in 100Mo to 99.5% and mass of 1199 g was measured deep underground (3600 m w.e.) in the Laboratori Nazionali del Gran Sasso of INFN, Italy; during 17249 h with a low-background set-up with 4 HP Ge detectors. After 2β2ν decay of 100Mo to the 0+1 excited level of 100Ru (Eexc = 1131 keV), two γ quanta of 540 keV and 591 keV should be emitted in deexcitation process. Both these γ's are observed in the accumulated data as in coincidence spectrum as well in 1-dimensional sum spectrum. Measured half life is T1/2 = (7.0+1.1−0.8) × 1020 yr, in agreement with positive results obtained in previous experiments.
Journal of Physics Conference Series 02/2010; 203(1):012142.
-
[show abstract]
[hide abstract]
ABSTRACT: A small CeCl3 crystal (6.9 g) was measured deep underground (3600 m w.e.) at the Gran Sasso National Laboratories of the INFN (Italy) with a low background HP Ge detector (244 cm3) during 1280 h. The crystal is not polluted by 232Th, 40K, 60Co, 137Cs (limits were set on the activity at a level of 0.05–1 Bq/kg), but contains radioactive 138La (0.68 Bq/kg) and, probably, is polluted by 235U and 238U (0.3–0.7 Bq/kg). The half life limits for different double β processes in 136Ce and in 138Ce were set in the range of (1–6)×1015 yr. In particular, the 2ε captures in 136Ce to various excited levels of 136Ba were considered for the first time. The limits for the resonant neutrinoless transitions to the 2392.1 keV and 2399.9 keV levels of 136Ba are: T1/2>2.4×1015 yr and T1/2>4.1×1015 yr at 90% C.L., respectively.
Nuclear Physics A. 04/2009; 824:101-114.
-
P. Belli,
R. Bernabei,
F. Cappella,
R. Cerulli,
F. A. Danevich, S. d'Angelo,
A. Incicchitti,
V. V. Kobychev,
S. S. Nagorny,
F. Nozzoli,
V. M. Mokina,
D. V. Poda,
D. Prosperi,
V. I. Tretyak
[show abstract]
[hide abstract]
ABSTRACT: The search for double-β processes in 108Cd and 114Cd was realized by using data of the low-background experiment with the CdWO4 crystal scintillator at the Gran Sasso National Laboratories of the INFN. New improved half-life limits on double-beta processes
were established, in particular T
1/2
0ν2ɛ( ^108Cd ) ≥ 1.0(2.7)×1018 yr, T
1/2
2ν2β( ^114Cd ) ≥ 1.3(2.1)×1018 yr, and T
1/2
0ν2β( ^114Cd ) ≥ 1.1(2.5)×1021 yr at 90(68)% C.L.
European Physical Journal A 05/2008; 36(2):167-170. · 2.19 Impact Factor
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P Belli,
R Bernabei,
F Cappella,
R Cerulli,
F A Danevich, S D'Angelo,
A Incicchitti,
V V Kobychev,
S S Nagorny,
F Nozzoli,
V M Mokina,
D V Poda,
D Prosperi,
V I Tretyak
[show abstract]
[hide abstract]
ABSTRACT: The search for double-beta processes in (108)Cd and (114)Cd was realized by using data of the low-background experiment with the CdWO(4) crystal scintillator at the Gran Sasso National Laboratories of the INFN. New improved half-life limits on double-beta processes were established, in particular T(1/2)(0 nu 2 epsilon)((108)Cd) >= 1.0(2.7) x 10(18) yr, T(1/2)(2 nu 2 beta)((114)Cd) >= 1.3(2.1) x 10(18) yr, and T(1/2)(0 nu 2 beta)((114)Cd) >= 1.1(2.5) x 10(21) yr at 90(68)% C.L.
European Physical Journal A 05/2008; 36(2):167-170. · 2.19 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: The very forward region of the experiment UA1 at the CERN p Collider will be equipped with calorimeters to detect photons and hadrons of energy 5-250 GeV. To localize electromagnetic showers large cell drift chambers will be housed between the modula of the calorimeters. The image of showers will be recorded in two projections by measuring continuously with fast analog to digital converters the drift time and the charge division along the wires. A prototype chamber made up of two 19 cm long drift cells, divided by two rows of 70 cm long anode wires has been built in Rome and tested at CERN with single ionizing particles and showers of energy 5-50 GeV. Results as a function of the shower energy and the ionization rate are reported.
Physica Scripta 01/2007; 23(4B):662. · 1.20 Impact Factor
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M. Altmann,
M. Balata,
P. Belli,
E. Bellotti,
R. Bernabei,
E. Burkert,
C. Cattadori,
R. Cerulli,
M. Chiarini,
M. Cribier, [......],
S. Nisi,
J. Oehm,
L. Pandola,
F. Petricca,
W. Potzel,
H. Richter,
S. Schoenert,
M. Wallenius,
M. Wojcik,
L. Zanotti
[show abstract]
[hide abstract]
ABSTRACT: We report the complete GNO solar neutrino results for the measuring periods GNO III, GNO II, and GNO I. The result for GNO III (last 15 solar runs) is (1σ) or (1σ) with errors combined. The GNO experiment is now terminated after altogether 58 solar exposure runs that were performed between 20 May 1998 and 9 April 2003. The combined result for GNO (I + II + III) is (1σ) or (1σ) with errors combined in quadrature. Overall, gallium based solar observations at LNGS (first in GALLEX, later in GNO) lasted from 14 May 1991 through 9 April 2003. The joint result from 123 runs in GNO and GALLEX is [69.3±5.5(incl. syst)] SNU (1σ). The distribution of the individual run results is consistent with the hypothesis of a neutrino flux that is constant in time. Implications from the data in particle- and astrophysics are reiterated.
Physics Letters B. 05/2005;
-
GNO Collaboration,
M. Altmann,
M. Balata,
P. Belli,
E Bellotti,
R. Bernabei,
E. Burkert,
C. Cattadori,
G. Cerichelli,
M. Chiarini, [......],
T. Kirsten,
T. Lachenmaier,
J. Lanfranchi,
M. Laubenstein,
D. Motta,
W. Rau,
H. Richter,
S. Waenninger,
M. Wojcik,
L Zanotti
[show abstract]
[hide abstract]
ABSTRACT: We report the first GNO solar neutrino results for the measuring period GNOI, solar exposure time May 20, 1998 till January 12, 2000. In the present analysis, counting results for solar runs SR1 - SR19 were used till April 4, 2000. With counting completed for all but the last 3 runs (SR17 - SR19), the GNO I result is [65.8 +10.2 -9.6 (stat.) +3.4 -3.6 (syst.)]SNU (1sigma) or [65.8 + 10.7 -10.2 (incl. syst.)]SNU (1sigma) with errors combined. This may be compared to the result for Gallex(I-IV), which is [77.5 +7.6 -7.8 (incl. syst.)] SNU (1sigma). A combined result from both GNOI and Gallex(I-IV) together is [74.1 + 6.7 -6.8 (incl. syst.)] SNU (1sigma). Comment: submitted to Physics Letters B, June 2000. PACS: 26.65. +t ; 14.60 Pq. Corresponding author: till.kirsten@mpi-hd.mpg.de ; bellotti@mi.infn.it
06/2000;
-
Geoffrey T J Arnison,
Alan Astbury,
Bernard Aubert,
Cesare Bacci,
R. Bernabei,
Alain-Arthur Bézaguet,
R K Böck,
T J V Bowcock,
M Calvetti,
T Carroll, [......],
P M Watkins,
J Wilson,
Michel Jean Paul Yvert,
Erwin Zurfluh,
T W Markiewicz,
M Pimiä,
J Ciborowski,
M Loret,
J J Malosse,
William Hugh Muirhead
-
Geoffrey T J Arnison,
Alan Astbury,
Bernard Aubert,
Cesare Bacci,
R. Bernabei,
Alain-Arthur Bézaguet,
R K Böck,
T J V Bowcock,
M Calvetti,
T Carroll, [......],
E Tscheslog,
Jorma Tuominiemi,
J P Vaille,
J Vrana,
V Vuillemin,
H Wahl,
P M Watkins,
J Wilson,
Michel Jean Paul Yvert,
Erwin Zurfluh
-
Geoffrey T J Arnison,
Alan Astbury,
Bernard Aubert,
Cesare Bacci,
R. Bernabei,
Alain-Arthur Bézaguet,
R K Böck,
T J V Bowcock,
M Calvetti,
T Carroll, [......],
E Tscheslog,
Jorma Tuominiemi,
J P Vialle,
J Vrana,
V Vuillemin,
H Wahl,
P M Watkins,
J Wilson,
Michel Jean Paul Yvert,
Erwin Zurfluh
-
Geoffrey T J Arnison,
Alan Astbury,
Bernard Aubert,
Cesare Bacci,
R. Bernabei,
Alain-Arthur Bézaguet,
R K Böck,
T J V Bowcock,
M Calvetti,
T Carroll, [......],
V Vuillemin,
H Wahl,
P M Watkins,
J Wilson,
Michel Jean Paul Yvert,
Erwin Zurfluh,
T W Markiewicz,
M Pimiä,
Michel Rabany,
Giuseppe Vismara
