We present an evaluation of the cross section for the reaction
12C(
n,X)
7Be. This reaction is relevant to the formation of cosmogenic background in low-energy real time solar neutrino detectors ...employing carbon-based scintillators. We measured this cross section by using a quasi-monoenergetic (max. 63
MeV) neutron beam at the Centre de Recherches du Cyclotron at Louvain-la-neuve; the produced
7Be nuclei were detected by means of low background germanium gamma spectroscopy at the Laboratori Nazionali del Gran Sasso (LNGS).
The Gran Sasso National Laboratory in Italy (LNGS) is at present the largest deep underground laboratory in the world. LNGS has been in operation for 35 years. It has a rock overburden of 1.4 km ...which reduces the muon flux from cosmic rays by a factor of one million.
A new setup for the underground study of capture reactions Casella, C; Costantini, H; Lemut, A ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2002, Letnik:
489, Številka:
1
Journal Article
Recenzirano
For the study of astrophysically relevant capture reactions in the underground laboratory LUNA a new setup of high sensitivity has been implemented. The setup includes a windowless gas target, a 4
π ...BGO summing crystal, and beam calorimeters. The setup has been recently used to measure the d(p,γ)
3He cross-section for the first time within its solar Gamow peak, i.e. down to 2.5
keV c.m. energy. The features of the optimized setup are described.
180
m
Ta
is the longest-lived metastable state presently known. Its decay has not been observed yet. In this work, we report a new result on the decay of
180
m
Ta
obtained with a 2015.12-g tantalum ...sample measured for 527.7 d with an ultra-low background HPGe detector in the STELLA laboratory of the Laboratori Nazionali del Gran Sasso (LNGS), in Italy. Before the measurement, the sample has been stored deep-underground for ten years, resulting in subdominant background contributions from cosmogenically activated
182
Ta
. We observe no signal in the regions of interest and set half-life limits on the process for the two channels EC and
β
-
:
T
1
/
2
,
EC
>
1.6
×
10
18
year and
T
1
/
2
,
β
-
>
1.1
×
10
18
year (90% C. I.), respectively. We also set the limit on the
γ
de-excitation / IC channel:
T
1
/
2
,
IC
>
4.1
×
10
15
year (90% C. I.). These are, as of now, the most stringent bounds on the decay of
180
m
Ta
worldwide. Finally, we test the hypothetical scenarios of de-excitation of
180
m
Ta
by cosmological Dark Matter and constrain new parameter space for strongly-interacting dark-matter particle with mass up to
10
5
GeV.
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