Records |
Author |
Balibrea-Correa, J.; Lerendegui-Marco, J.; Calvo, D.; Caballero, L.; Babiano, V.; Ladarescu, I.; Redondo, M.L.; Tain, J.L.; Tolosa, A.; Domingo-Pardo, C.; Calvino, F.; Casanovas, A.; Tarifeño-Saldivia, A.; Alcayne, V.; Cano-Ott, D.; Martinez, T.; Guerrero, C.; Barbagallo, M.; Macina, D.; Bacak, M. |
Title |
A first prototype of C6D6 total-energy detector with SiPM readout for neutron capture time-of-flight experiments |
Type |
Journal Article |
Year |
2021 |
Publication |
Nuclear Instruments & Methods in Physics Research A |
Abbreviated Journal |
Nucl. Instrum. Methods Phys. Res. A |
Volume |
985 |
Issue |
|
Pages |
164709 - 8pp |
Keywords |
Silicon photomultiplier; Radiation detectors; Time-of-flight; Radiative capture; Total energy detector; Pulse-height weighting technique |
Abstract |
Low efficiency total-energy detectors (TEDs) are one of the main tools for neutron capture cross section measurements utilizing the time-of-flight (TOF) technique. State-of-the-art TEDs are based on a C6D6 liquid-scintillation cell optically coupled to a fast photomultiplier tube. The large photomultiplier tube represents yet a significant contribution to the so-called neutron sensitivity background, which is one of the most conspicuous sources of uncertainty in this type of experiments. Here we report on the development of a first prototype of a TED based on a silicon-photomultiplier (SiPM) readout, thus resulting in a lightweight and much more compact detector. Apart from the envisaged improvement in neutron sensitivity, the new system uses low voltage (+28 V) and low current supply (-50 mA), which is more practical than the-kV supply required by conventional photomultipliers. One important difficulty hindering the earlier implementation of SiPM readout for this type of detector was the large capacitance for the output signal when all pixels of a SiPM array are summed together. The latter leads to long pulse rise and decay times, which are not suitable for time-of-flight experiments. In this work we demonstrate the feasibility of a Schottky-diode multiplexing readout approach, that allows one to preserve the excellent timing properties of SiPMs, hereby paving the way for their implementation in future neutron TOF experiments. |
Address |
[Balibrea-Correa, J.; Lerendegui-Marco, J.; Calvo, D.; Caballero, L.; Babiano, V; Ladarescu, I; Redondo, M. Lopez; Tain, J. L.; Tolosa, A.; Domingo-Pardo, C.] Univ Valencia, Inst Fis Corpuscular, CSIC, Valencia, Spain, Email: dacaldia@ific.uv.es; |
Corporate Author |
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Thesis |
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Publisher |
Elsevier |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0168-9002 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
|
Notes |
WOS:000592358200019 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
4638 |
Permanent link to this record |
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Author |
Massimi, C.; Cristallo, S.; Domingo-Pardo, C.; Lederer-Woods, C. |
Title |
n_TOF: Measurements of Key Reactions of Interest to AGB Stars |
Type |
Journal Article |
Year |
2022 |
Publication |
Universe |
Abbreviated Journal |
Universe |
Volume |
8 |
Issue |
2 |
Pages |
100 - 19pp |
Keywords |
s process; MACS; time of flight |
Abstract |
In the last 20 years, the neutron time-of-flight facility nTOF at CERN has been providing relevant data for the astrophysical slow neutron capture process (s process). At nTOF, neutron-induced radiative capture (n,gamma) as well as (n,p) and (n,alpha) reaction cross sections are measured as a function of energy, using the time-of-flight method. Improved detection systems, innovative ideas and collaborations with other neutron facilities have lead to a considerable contribution of the n_TOF collaboration to studying the s process in asymptotic giant branch stars. Results have been reported for stable and radioactive samples, i.e.,Mg- 24,Mg-25,Mg-26, Al-26, S-33,Fe- 54,Fe-57, Ni-58,Ni-59,Ni-62,Ni-63, Ge-70,Ge-72,Ge-73, Zr-90,Zr-91,Zr-92,Zr-93,Zr-94,Zr-96, La-139, Ce-140, Pm-147, Sm-151,Gd- 154,Gd-155,Gd-157, Tm-171, Os-186,Os-187,Os-188, Au-197, Tl-203,Tl-204,Pb- 204,Pb-206,Pb-207 and Bi-209 isotopes, while others are being studied or planned to be studied in the near future. In this contribution, we present an overview of the most successful achievements, and an outlook of future challenging measurements, including ongoing detection system developments. |
Address |
[Massimi, Cristian] Univ Bologna, Dept Phys & Astron, I-40127 Bologna, Italy, Email: cristian.massimi@unibo.it; |
Corporate Author |
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Thesis |
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Publisher |
Mdpi |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
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ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000762514400001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
5144 |
Permanent link to this record |
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Author |
n_TOF Collaboration (Mazzone, A. et al); Babiano-Suarez, V; Caballero, L.; Domingo-Pardo, C.; Ladarescu, I; Tain, J.L. |
Title |
Measurement of the Gd-154(n, gamma) cross section and its astrophysical implications |
Type |
Journal Article |
Year |
2020 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
Volume |
804 |
Issue |
|
Pages |
135405 - 6pp |
Keywords |
s process; Gd-154; Neutron time of flight; n_TOF |
Abstract |
The neutron capture cross section of Gd-154 was measured from 1 eV to 300 keV in the experimental area located 185 m from the CERN n_TOF neutron spallation source, using a metallic sample of gadolinium, enriched to 67% in Gd-154. The capture measurement, performed with four C6D6 scintillation detectors, has been complemented by a transmission measurement performed at the GELINA time-of-flight facility (JRC-Geel), thus minimising the uncertainty related to sample composition. An accurate Maxwellian averaged capture cross section (MACS) was deduced over the temperature range of interest for s process nucleosynthesis modelling. We report a value of 880(50) mb for the MACS at kT = 30 keV, significantly lower compared to values available in literature. The new adopted Gd-154(n, gamma) cross section reduces the discrepancy between observed and calculated solar s-only isotopic abundances predicted by s-process nucleosynthesis models. |
Address |
[Mazzone, A.; Barbagallo, M.; Colonna, N.; Damone, L. A.; Tagliente, G.; Variale, V.] Ist Nazl Fis Nucl, Bari, Italy, Email: Cristian.Massimi@bo.infn.it |
Corporate Author |
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Thesis |
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Publisher |
Elsevier |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0370-2693 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000548740300022 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
4464 |
Permanent link to this record |
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Author |
n_TOF Collaboration (Massimi, C. et al.); Domingo-Pardo, C.; Giubrone, G.; Tain, J.L. |
Title |
Neutron spectroscopy of Mg-26 states: Constraining the stellar neutron source Ne-22(alpha, n)Mg-25 |
Type |
Journal Article |
Year |
2017 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
Volume |
768 |
Issue |
|
Pages |
1-6 |
Keywords |
s Process; alpha+Ne-22; Neutron spectroscopy |
Abstract |
This work reports on accurate, high-resolution measurements of the Mg-25(n, gamma)Mg-26 and Mg-25(n, tot) cross sections in the neutron energy range from thermal to about 300 keV, leading to a significantly improved Mg-25(n, gamma)Mg-26 parametrization. The relevant resonances for n+Mg-25 were characterized from a combined R-matrix analysis of the experimental data. This resulted in an unambiguous spin/parity assignment of the corresponding excited states in Mg-26. With this information experimental upper limits of the reaction rates for Ne-22(alpha, n)Mg-25 and Ne-22(alpha, gamma)Mg-26 were established, potentially leading to a significantly higher (alpha, n)/(alpha, gamma) ratio than previously evaluated. The impact of these results has been studied for stellar models in the mass range 2 to 25 M-circle dot. (C) 2017 The Author(s). Published by Elsevier B.V. |
Address |
[Massimi, C.; Barbagallo, M.; Becvar, F.; Bisterzok, S.; Castelluccio, D. M.; Eleftheriadis, C.; Finocchiaro, P.; Kokkoris, M.; Marganiec, J.; Plompen, A.; Praena, J.; Rubbia, C.; Weiss, C.] Ist Nazl Fis Nucl, Bologna, Italy, Email: cristian.massimi@bo.infn.it |
Corporate Author |
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Thesis |
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Publisher |
Elsevier Science Bv |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0370-2693 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
|
Notes |
WOS:000400677700001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
3112 |
Permanent link to this record |
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|
Author |
Domingo-Pardo, C. |
Title |
i-TED: A novel concept for high-sensitivity (n,gamma) cross-section measurements |
Type |
Journal Article |
Year |
2016 |
Publication |
Nuclear Instruments & Methods in Physics Research A |
Abbreviated Journal |
Nucl. Instrum. Methods Phys. Res. A |
Volume |
825 |
Issue |
|
Pages |
78-86 |
Keywords |
Radiative neutron capture; Neutron time-of-flight; Cross-section; Pulse-height weighting technique; Compton imaging |
Abstract |
A new method for measuring (n, gamma) cross-sections aiming at enhanced signal-to-background ratio is presented. This new approach is based on the combination of the pulse-height weighting technique with a total energy detection system that features gamma-ray imaging capability (i-TED). The latter allows one to exploit Compton imaging techniques to discriminate between true capture gamma-rays arising from the sample under study and background gamma-rays coming from contaminant neutron (prompt or delayed) captures in the surrounding environment. A general proof-of-concept detection system for this application is presented in this paper together with a description of the imaging method and a conceptual demonstration based on Monte Carlo simulations. |
Address |
[Domingo-Pardo, C.] Univ Valencia, CSIC, Inst Fis Corpuscular, E-46003 Valencia, Spain |
Corporate Author |
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Thesis |
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Publisher |
Elsevier Science Bv |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0168-9002 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000376713700010 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
no |
Call Number |
IFIC @ pastor @ |
Serial |
2686 |
Permanent link to this record |