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Author Guerrero, C.; Domingo-Pardo, C.; Kappeler, F.; Lerendegui-Marco, J.; Palomo, F.R.; Quesada, J.M.; Reifarth, R.
Title Prospects for direct neutron capture measurements on s-process branching point isotopes Type Journal Article
Year 2017 Publication European Physical Journal A Abbreviated Journal Eur. Phys. J. A
Volume 53 Issue 5 Pages 87 - 5pp
Keywords (up)
Abstract The neutron capture cross sections of several unstable key isotopes acting as branching points in the s-process are crucial for stellar nucleosynthesis studies, but they are very challenging to measure directly due to the difficult production of sufficient sample material, the high activity of the resulting samples, and the actual (n, gamma) measurement, where high neutron fluxes and effective background rejection capabilities are required. At present there are about 21 relevant s-process branching point isotopes whose cross section could not be measured yet over the neutron energy range of interest for astrophysics. However, the situation is changing with some very recent developments and upcoming technologies. This work introduces three techniques that will change the current paradigm in the field: the use of gamma-ray imaging techniques in (n,gamma) experiments, the production of moderated neutron beams using high-power lasers, and double capture experiments in Maxwellian neutron beams.
Address [Guerrero, C.; Lerendegui-Marco, J.; Quesada, J. M.] Univ Seville, Dept Fis Atom Mol & Nucl, E-41012 Seville, Spain, Email: carlos.guerrero@cern.ch
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6001 ISBN Medium
Area Expedition Conference
Notes WOS:000400982700002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3129
Permanent link to this record
 
 
Author n_TOF Collaboration (Lerendegui-Marco, J. et al.); Domingo-Pardo, C.; Tain, J.L.; Tarifeño-Saldivia, A.
Title Radiative neutron capture on Pu-242 in the resonance region at the CERN n_TOF-EAR1 facility Type Journal Article
Year 2018 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 97 Issue 2 Pages 024605 - 21pp
Keywords (up)
Abstract The spent fuel of current nuclear reactors contains fissile plutonium isotopes that can be combined with uranium to make mixed oxide (MOX) fuel. In this way the Pu from spent fuel is used in a new reactor cycle, contributing to the long-term sustainability of nuclear energy. However, an extensive use of MOX fuels, in particular in fast reactors, requires more accurate capture and fission cross sections for some Pu isotopes. In the case of Pu-242 there are sizable discrepancies among the existing capture cross-section measurements included in the evaluations (all from the 1970s) resulting in an uncertainty as high as 35% in the fast energy region. Moreover, postirradiation experiments evaluated with JEFF-3.1 indicate an overestimation of 14% in the capture cross section in the fast neutron energy region. In this context, the Nuclear Energy Agency (NEA) requested an accuracy of 8% in this cross section in the energy region between 500 meV and 500 keV. This paper presents a new time-of-flight capture measurement on Pu-242 carried out at nTOF-EAR1 (CERN), focusing on the analysis and statistical properties of the resonance region, below 4 keV. The Pu-242(n, gamma) reaction on a sample containing 95(4) mg enriched to 99.959% was measured with an array of four C6D6 detectors and applying the total energy detection technique. The high neutron energy resolution of nTOF-EAR1 and the good statistics accumulated have allowed us to extend the resonance analysis up to 4 keV, obtaining new individual and average resonance parameters from a capture cross section featuring a systematic uncertainty of 5%, fulfilling the request of the NEA.
Address [Lerendegui-Marco, J.; Guerrero, C.; Quesada, J. M.; Cortes-Giraldo, M. A.; Praena, J.; Sabate-Gilarte, M.] Univ Seville, Dept Fis Atom Mol & Nucl, E-41012 Seville, Spain, Email: cguerrero4@us.es
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9985 ISBN Medium
Area Expedition Conference
Notes WOS:000424190700001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3474
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Author Babiano-Suarez, V. et al; Lerendegui-Marco, J.; Balibrea-Correa, J.; Caballero, L.; Calvo, D.; Ladarescu, I.; Real, D.; Domingo-Pardo, C.
Title Imaging neutron capture cross sections: i-TED proof-of-concept and future prospects based on Machine-Learning techniques Type Journal Article
Year 2021 Publication European Physical Journal A Abbreviated Journal Eur. Phys. J. A
Volume 57 Issue 6 Pages 197 - 17pp
Keywords (up)
Abstract i-TED is an innovative detection system which exploits Compton imaging techniques to achieve a superior signal-to-background ratio in (n, gamma) cross-section measurements using time-of-flight technique. This work presents the first experimental validation of the i-TED apparatus for high-resolution time-of-flight experiments and demonstrates for the first time the concept proposed for background rejection. To this aim, the Au-197(n, gamma) and Fe-56(n, gamma) reactions were studied at CERN n_TOF using an i-TED demonstrator based on three position-sensitive detectors. Two C6D6 detectors were also used to benchmark the performance of i-TED. The i-TED prototype built for this study shows a factor of similar to 3 higher detection sensitivity than state-of-the-art C6D6 detectors in the 10 keV neutron-energy region of astrophysical interest. This paper explores also the perspectives of further enhancement in performance attainable with the final i-TED array consisting of twenty position-sensitive detectors and newanalysis methodologies based on Machine-Learning techniques.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6001 ISBN Medium
Area Expedition Conference
Notes WOS:000662881100001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4875
Permanent link to this record
 
 
Author Lerendegui-Marco, J.; Balibrea-Correa, J.; Babiano-Suarez, V.; Ladarescu, I.; Domingo-Pardo, C.
Title Towards machine learning aided real-time range imaging in proton therapy Type Journal Article
Year 2022 Publication Scientific Reports Abbreviated Journal Sci Rep
Volume 12 Issue 1 Pages 2735 - 17pp
Keywords (up)
Abstract Compton imaging represents a promising technique for range verification in proton therapy treatments. In this work, we report on the advantageous aspects of the i-TED detector for proton-range monitoring, based on the results of the first Monte Carlo study of its applicability to this field. i-TED is an array of Compton cameras, that have been specifically designed for neutron-capture nuclear physics experiments, which are characterized by gamma-ray energies spanning up to 5-6 MeV, rather low gamma-ray emission yields and very intense neutron induced gamma-ray backgrounds. Our developments to cope with these three aspects are concomitant with those required in the field of hadron therapy, especially in terms of high efficiency for real-time monitoring, low sensitivity to neutron backgrounds and reliable performance at the high gamma-ray energies. We find that signal-to-background ratios can be appreciably improved with i-TED thanks to its light-weight design and the low neutron-capture cross sections of its LaCl3 crystals, when compared to other similar systems based on LYSO, CdZnTe or LaBr3. Its high time-resolution (CRT similar to 500 ps) represents an additional advantage for background suppression when operated in pulsed HT mode. Each i-TED Compton module features two detection planes of very large LaCl3 monolithic crystals, thereby achieving a high efficiency in coincidence of 0.2% for a point-like 1 MeV gamma-ray source at 5 cm distance. This leads to sufficient statistics for reliable image reconstruction with an array of four i-TED detectors assuming clinical intensities of 10(8) protons per treatment point. The use of a two-plane design instead of three-planes has been preferred owing to the higher attainable efficiency for double time-coincidences than for threefold events. The loss of full-energy events for high energy gamma-rays is compensated by means of machine-learning based algorithms, which allow one to enhance the signal-to-total ratio up to a factor of 2.
Address [Lerendegui-Marco, Jorge; Balibrea-Correa, Javier; Babiano-Suarez, Victor; Ladarescu, Ion; Domingo-Pardo, Cesar] Univ Valencia, CSIC, Inst Fis Corpuscular, Valencia, Spain, Email: jorge.lerendegui@ific.uv.es
Corporate Author Thesis
Publisher Nature Portfolio Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2045-2322 ISBN Medium
Area Expedition Conference
Notes WOS:000757537100018 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 5136
Permanent link to this record
 
 
Author Balibrea-Correa, J.; Lerendegui-Marco, J.; Ladarescu, I.; Guerrero, C.; Rodriguez-Gonzalez, T.; Jimenez-Ramos, M.C.; Fernandez-Martinez, B.; Domingo-Pardo, C.
Title Hybrid in-beam PET- and Compton prompt-gamma imaging aimed at enhanced proton-range verification Type Journal Article
Year 2022 Publication European Physical Journal Plus Abbreviated Journal Eur. Phys. J. Plus
Volume 137 Issue 11 Pages 1258 - 18pp
Keywords (up)
Abstract We report on a hybrid in-beam PET and prompt-gamma Compton imaging system aimed at quasi real-time ion-range verification in proton-therapy treatments. Proof-of-concept experiments were carried out at the radiobiology beam line of the CNA cyclotron facility using a set of two synchronous Compton imagers and different target materials. The time structure of the 18 MeV proton beam was shaped with a series of beam-on and beam-off intervals, thereby mimicking a pulsed proton beam on a long time scale. During beam-on intervals, Compton imagingwas performed utilizing the high energy. -rays promptly emitted from the nuclear reactions occurring in the targets. In the course of the beam-off intervals in situ positron-emission tomography was accomplished with the same imagers using the beta+ decay of activated nuclei. The targets used were stacks of different materials covering also various proton ranges and energies. A systematic study on the performance of these two complementary imaging techniques is reported and the experimental results interpreted on the basis ofMonte Carlo calculations. The results demonstrate the possibility to combine both imaging techniques in a concomitant way, where high-efficiency prompt-gamma imaging is complemented with the high spatial accuracy of PET. Empowered by these results we suggest that a pulsed beam with a suitable duty cycle, in conjunction with in situ Compton- and PET-imaging may help to attain complementary information and quasi real-time range monitoring with high accuracy.
Address [Balibrea-Correa, J.; Lerendegui-Marco, J.; Ladarescu, I; Domingo-Pardo, C.] Univ Valencia, CSIC, Inst Fis Corpuscular, Valencia, Spain, Email: javier.balibrea@ific.uv.es
Corporate Author Thesis
Publisher Springer Heidelberg Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2190-5444 ISBN Medium
Area Expedition Conference
Notes WOS:000886327900002 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 5420
Permanent link to this record