Horia Petrascu | Horia Hulubei National Institute for Physics and Nuclear Engineering Bucharest (original) (raw)

Papers by Horia Petrascu

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2013

The next generation of 4p detector arrays for heavy ion studies will largely use Pulse Shape Anal... more The next generation of 4p detector arrays for heavy ion studies will largely use Pulse Shape Analysis to push the performance of silicon detectors with respect to ion identification. Energy resolution and pulse shape identification capabilities of silicon detectors under prolonged irradiation by energetic heavy ions have thus become a major issue. In this framework, we have studied the effects of irradiation by energetic heavy ions on the response of neutron transmutation doped (nTD) silicon detectors. Sizeable effects on the amplitude and the risetime of the charge signal have been found for detectors irradiated with large fluences of stopped heavy ions, while much weaker effects were observed by punchingthrough ions. The robustness of ion identification based on digital pulse shape techniques has been evaluated.

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2012

Abstract The response of silicon–silicon–CsI(Tl) and silicon–CsI(Tl) telescopes to fragments prod... more Abstract The response of silicon–silicon–CsI(Tl) and silicon–CsI(Tl) telescopes to fragments produced in nuclear interactions has been studied. The telescopes were developed within the FAZIA collaboration. The capabilities of two methods are compared: (a) the standard Δ E – E technique and (b) the digital Pulse Shape Analysis technique (for identification of nuclear fragments stopped in a single Si-layer). In a test setup, nuclear fragments covering a large range in nuclear charge, mass and energy were detected. They were produced in nuclear reactions induced by a 35A MeV beam of 129Xe impinging on various targets. It was found that the Δ E – E correlations allow the identification of all isotopes up to Z ∼ 25 . With the digital Pulse Shape Analysis it is possible to fully distinguish the charge of stopped nuclei up to the maximum available Z (slightly over that of the beam, Z=54).

International Journal of Modern Physics A

NUMEN proposes an innovative technique to access the nuclear matrix elements entering the express... more NUMEN proposes an innovative technique to access the nuclear matrix elements entering the expression of the lifetime of the double beta decay by cross-section measurements of heavy-ion induced Double Charge Exchange (DCE) reactions. Despite the fact that the two processes, namely neutrinoless double beta decay and DCE reactions, are triggered by the weak and strong interaction respectively, important analogies are suggested. The basic point is the coincidence of the initial and final state many-body wave functions in the two types of processes and the formal similarity of the transition operators. The main experimental tools for this project are the K800 Superconducting Cyclotron and MAGNEX spectrometer at the INFN-LNS laboratory. However, the tiny values of DCE cross-sections and the resolution requirements demand beam intensities much higher than those manageable with the present facility. The on-going upgrade of the INFN-LNS facilities promoted by the POTLNS a project in this per...

Development of a VME (Versa Module Eurocard) complex neutron measurement system using a neutron a... more Development of a VME (Versa Module Eurocard) complex neutron measurement system using a neutron array detector based on time of flight method (TOF) at IFIN-HH Tandem accelerator for investigation of neutron-neutron correlations by the interferometry techniques of two identical particles is described. This is based on the fact that the n-n correlation function is extremely sensitive against the space-time dimensions of the area from which the neutrons were emitted. The new features include the use of an array detector with 81 scintillators, a compact multipurpose reaction chamber, a multi-entrances high voltage source, a VME coincidence data acquisition and a standard network of a fast/slow coincidence electronics. In particular, the details of design, fabrication and assembly of components engaged in the setup are presented. Selected experiments planned with the setup are mentioned and briefly discussed. The quantitative determination of the detection’s threshold for neutrons energy...

EPJ Web of Conferences

The possibility to use a special class of heavy-ion induced direct reactions, such as double char... more The possibility to use a special class of heavy-ion induced direct reactions, such as double charge exchange reactions, is discussed in view of their application to extract information that may be helpful to determinate the nuclear matrix elements entering in the expression of neutrinoless double beta decay half-life. The strategies adopted in the experimental campaigns performed at INFN - Laboratori Nazionali del Sud are briefly described, emphasizing the advantages of the multi-channel approach to nuclear reaction data analysis.

Universe

Neutrinos are so far the most elusive known particles, and in the last decades many sophisticated... more Neutrinos are so far the most elusive known particles, and in the last decades many sophisticated experiments have been set up in order to clarify several questions about their intrinsic nature, in particular their masses, mass hierarchy, intrinsic nature of Majorana or Dirac particles. Evidence of the Neutrinoless Double-Beta Decay (NDBD) would prove that neutrinos are Majorana particles, thus improving the understanding of the universe itself. Besides the search for several large underground experiments for the direct experimental detection of NDBD, the NUMEN experiment proposes the investigation of a nuclear mechanism strongly linked to this decay: the Double Charge Exchange reactions (DCE). As such reactions share with the NDBD the same initial and final nuclear states, they could shed light on the determination of the Nuclear Matrix Elements (NMEs), which play a relevant role in the decay. The physics of DCE is described elsewhere in this issue, while the focus of this paper wi...

Universe

Double charge exchange (DCE) reactions could provide experimentally driven information about nucl... more Double charge exchange (DCE) reactions could provide experimentally driven information about nuclear matrix elements of interest in the context of neutrinoless double-β decay. To achieve this goal, a detailed description of the reaction mechanism is mandatory. This requires the full characterization of the initial and final-state interactions, which are poorly known for many of the projectile-target systems involved in future DCE studies. Among these, we intend to study the 20Ne + 130Te and 18O + 116Sn systems at 15.3 AMeV, which are particularly relevant due to their connection with the 130Te→130Xe and 116Cd→116Sn double-β decays. We measure the elastic and inelastic scattering cross-section angular distributions and compare them with theoretical calculations performed in the optical model, one-step distorted wave Born approximation, and coupled-channel approaches using the São Paulo double-folding optical potential. A good description of the experimental data in the whole explored...

Frontiers in Astronomy and Space Sciences

The goal of NUMEN project is to access experimentally driven information on Nuclear Matrix Elemen... more The goal of NUMEN project is to access experimentally driven information on Nuclear Matrix Elements (NME) involved in the neutrinoless double beta decay (0νββ) by accurate measurements of the cross sections of heavy-ion induced double charge-exchange reactions. In particular, the (18O, 18Ne) and (20Ne, 20O) reactions are adopted as tools for β+β+ and β−β− decays, respectively. The experiments are performed at INFN–Laboratory Nazionali del Sud (LNS) in Catania using the Superconducting Cyclotron to accelerate the beams and the MAGNEX magnetic spectrometer to detect the reaction products. The measured cross sections are very low, limiting the present exploration to few selected isotopes of interest in the context of typically low-yield experimental runs. In order to make feasible a systematic study of all the candidate nuclei, a major upgrade of the LNS facility is foreseen to increase the experimental yield by more than two orders of magnitude. To this purpose, frontier technologies ...

EPJ Web of Conferences

The possibility to use a special class of heavy-ion induced direct reactions, such as double char... more The possibility to use a special class of heavy-ion induced direct reactions, such as double charge exchange reactions, is discussed in view of their application to extract information that may be helpful to determinate the nuclear matrix elements entering in the expression of neutrinoless double beta decay half-life. The methodology of the experimental campaign presently running at INFN - Laboratori Nazionali del Sud is reported andthe experimental challenges characterizing such activity are described.

Proceedings of 55th International Winter Meeting on Nuclear Physics — PoS(BORMIO2017)

Symmetries and Order: Algebraic Methods in Many Body Systems: A symposium in celebration of the career of Professor Francesco Iachello

The NUMEN project aims at accessing experimentally driven information on Nuclear Matrix Elements ... more The NUMEN project aims at accessing experimentally driven information on Nuclear Matrix Elements (NME) involved in the half-life of the neutrinoless double beta decay (0), by high-accuracy measurements of the cross sections of Heavy Ion (HI) induced Double Charge Exchange (DCE) reactions. Particular interest is given to the (18 O, 18 Ne) and (20 Ne, 20 O) reactions as tools for + + and-decays, respectively. First evidence about the possibility to get quantitative information about NME from experiments is found for both kind of reactions. In the experiments, performed at INFN-Laboratory Nazionali del Sud (LNS) in Catania, the beams are accelerated by the Superconducting Cyclotron (CS) and the reaction products are detected by the MAGNEX magnetic spectrometer. The measured cross sections are challengingly low, limiting the present exploration to few selected isotopes of interest in the context of typically low-yield experimental runs. A major upgrade of the LNS facility is foreseen in order to significantly increase the experimental yield, thus making feasible a systematic study of all the cases of interest. Frontiers technologies are going to be developed, to this purpose, for the accelerator and the detection systems. In parallel, advanced theoretical models are developed aiming at extracting the nuclear structure information from the measured cross sections.

Proceedings of Neutrino Oscillation Workshop — PoS(NOW2018)

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2013

Data on the spectroscopy of 5H and 7He from recent experiments with radioactive beams in Dubna an... more Data on the spectroscopy of 5H and 7He from recent experiments with radioactive beams in Dubna and in RIKEN are presented.

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2013

Physical Review C, 2006

For the first time to our knowledge the target screening effect on the pre-emission of halo neutr... more For the first time to our knowledge the target screening effect on the pre-emission of halo neutrons from Li11 has been quantitatively analyzed. Our work has been performed in the 7.5 15 MeV neutron energy range. In this range the target nuclei are likely to behave as opaque, and therefore the sharp-cutoff calculations are most appropriate for the target screening

Physical Review C, 2004

The recent experiment with a new array detector aiming the investigation of halo neutron pair pre... more The recent experiment with a new array detector aiming the investigation of halo neutron pair pre-emission in Si( 11 Li , fusion) is described. A new approach for testing the true n-n coincidences against cross-talk has been worked out. An experimental evidence for residual correlation of the pre-emitted halo neutrons is presented. The results obtained in building the nn correlation

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2013

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2012

International Journal of Modern Physics A

EPJ Web of Conferences

Universe

Frontiers in Astronomy and Space Sciences

EPJ Web of Conferences

The possibility to use a special class of heavy-ion induced direct reactions, such as double char... more The possibility to use a special class of heavy-ion induced direct reactions, such as double charge exchange reactions, is discussed in view of their application to extract information that may be helpful to determinate the nuclear matrix elements entering in the expression of neutrinoless double beta decay half-life. The methodology of the experimental campaign presently running at INFN - Laboratori Nazionali del Sud is reported andthe experimental challenges characterizing such activity are described.

Proceedings of 55th International Winter Meeting on Nuclear Physics — PoS(BORMIO2017)

Symmetries and Order: Algebraic Methods in Many Body Systems: A symposium in celebration of the career of Professor Francesco Iachello

Proceedings of Neutrino Oscillation Workshop — PoS(NOW2018)

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2013

Physical Review C, 2006

Physical Review C, 2004