Global study of 9 Be + p at 2.72 A MeV

Background: In our recent experiment, 9 Be + p at 5.67 A MeV, the breakup decay rates to the three configurations, α + α + n , 8 Be ∗ + n and 5 He + 4 He of 9 Be , were observed and quantified in the proton recoil spectra, in a full kinematics approach. Unfolding step by step the accessibility to the above configurations, it will require similar experiments at lower or/and higher energies. It will also require the interpretation of the data in a theoretical framework. Three-body models for the structure of 9 Be have been developed and applied to reactions with heavy targets. Further research on lighter targets is required for the best establishment of the model. Such models are relevant for the calculation of the corresponding radiative capture reaction rate, α ( α , γ ) 9 Be followed by 9 Be ( α , n ) 12 C . The last is essential for the r -process abundance predictions. Purpose: Investigate the breakup decay rate of 9 Be + p at 2.72 A MeV, where the direct configuration α + α + n is mainly accessible. Compare and interpret data at this low energy and at the higher energy of 5.67 A MeV into a four-body continuum discretized coupled-channel formalism. Point out and discuss couplings to continuum. Methods: Our experimental method includes an exclusive breakup measurement in a full kinematic approach of 9 Be incident on a proton target at 24.5 MeV ( 2.72 A MeV). Complementary the elastic scattering is measured and other reaction channels are evaluated from previous measurements under the same experimental conditions. The interpretation of present data at 2.72 A MeV and previous data at 5.67 A MeV, are considered in a four-body continuum discretized coupled channel (CDCC) approach, using the transformed harmonic oscillator method for the three-body projectile. Results: An elastic scattering angular distribution at 2.72 A MeV is measured, which compares very well with CDCC calculations, indicating a strong coupling to continuum. At the same energy, the breakup and total reaction cross sections are measured as σ break = 2.5 ± 1 mb and σ tot = 510 ± L 90 mb , in good agreement with the calculated values of 3.7 and 433 mb, respectively. Further on, into the same theoretical framework, the elastic scattering and breakup cross section data at 5.67 A MeV are found in very good agreement with the CDCC calculations. Conclusions: It was confirmed in a global experimental framework that four-body CDCC calculations can describe very well the data even at low energies. Coupling to continuum is very strong despite the small measured breakup cross section. Moreover, the present results support further our three-body model for the structure of 9 Be , validating relevant radiative reaction rates obtained previously.Programa de investigación e innovación de la Unión Europea HORIZON2020 No. 654002-ENSAR2European Research Council (ERC) 714625Ministerio de Ciencia, Innovación y Universidades de España. PGC2018-095640-B-I00Ministerio de España de Economía y Competitividad y Fondo de Desarrollo de la Unión Europea (FEDER) FIS2017- 88410-PFondos SID 2019 (Università degli Studi di Padua, Italia) CASA_SID19_0

Identification of medium mass (A=60-80) ejectiles from 15 MeV/nucleon peripheral heavy-ion collisions with the MAGNEX large-acceptance spectrometer

An approach to identify medium-mass ejectiles from peripheral heavy-ion reactions in the energy region of 15 MeV/nucleon is developed for data obtained with a large acceptance magnetic spectrometer. This spectrometer is equipped with a focal plane multidetector, providing position, angle, energy loss and residual energy of the ions along with measurement of the time-of-flight. Ion trajectory reconstruction is performed at high order and ion mass is obtained with a resolution of better than 1/150. For the unambiguous particle identification however, the reconstruction of both the atomic number Z and the ionic charge q of the ions is critical and it is suggested, within this work, to be performed prior to mass identification. The new proposed method was successfully applied to MAGNEX spectrometer data, for identifying neutron-rich ejectiles related to multinucleon transfer generated in the 70Zn+ 64Ni collision at 15 MeV/nucleon. This approach opens up the possibility of employing heavy-ion reactions with medium-mass beams below the Fermi energy (i.e., in the region 15-25 MeV/nucleon) in conjunction with large acceptance ray tracing spectrometers, first, to study the mechanism(s) of nucleon transfer in these reactions and, second, to produce and study very neutron-rich or even new nuclides in previously unexplored regions of the nuclear landscape.Comment: 6 pages, 6figure

Characterization of a gas detector prototype based on Thick-GEM for the MAGNEX focal plane detector

A new gas detector prototype for the upgrade of the focal plane detector of the MAGNEX large-acceptance magnetic spectrometer has been developed and tested in view of the NUMEN project. It has been designed to operate at low gas pressure for detecting medium to heavy ions in the energy range between 15 and 60 AMeV. It is a drift chamber based on Multi-layer Thick-GEM (M-THGEM) as electron multiplication technology. Tests with two different M-THGEM layouts have been performed using both a radioactive $\alpha$-particle source and accelerated heavy-ion beams. The characterization of the detector in terms of measured currents that flow through the electrodes as a function of different parameters, including applied voltages, gas pressure and rate of incident particle, is described. The gain and ion backflow properties have been studied

Reexamination of 6Li + p elastic scattering in inverse kinematics

Elastic-scattering measurements have been performed for the Li6+p system in inverse kinematics at the energies of 16, 20, 25, and 29 MeV. The heavy ejectile was detected by the large acceptance MAGNEX spectrometer at the Laboratori Nazionali del Sud in Catania, Italy. The results are considered in a Jeukenne-Lejeune-Mahaux and a continuum discretized coupled-channel calculation framework

Does clinical method mask significant VTE-related mortality and morbidity in malignant disease?

After more than 150 years of a recognised link between cancer and vascular thromboembolic events (VTE), and despite a greatly improved understanding of its pathophysiology, epidemiology and treatment, the management of patients with cancer and VTE is still limited. Limitations can be related to the thromboembolism itself, the underlying cancer, or to the management process. There is significant literature that deals with the first two, but very little regarding the systems we use, or how the inadequacies in documentation, identification and classification of VTE affect the cancer patients themselves. This review aims to raise awareness of this neglected area and stimulate research that may lead to improvements in patient care

Background estimate in heavy-ion two-body reactions measured by the MAGNEX spectrometer

The MAGNEX magnetic spectrometer is nowadays used in the experimental measurements of rare quasi-elastic reactions between heavy ions at intermediate energy within the NUMEN project. The small cross sections involved in such processes under the large yields due to competitive reaction channels have motivated an accurate control of the background sources. In such view, the not ideal particle identification could introduce spurious contributions which have been identified and evaluated in the present analysis

The NUMEN heavy ion multidetector for a complementary approach to the neutrinoless double beta decay

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 will be on the challenging experimental apparatus currently under construction in order to fulfil the requirements of the NUMEN experiment. The overall structure of the technological improvement to the cyclotron, along with the newly developed detection systems required for tracking and identifying the reaction products and their final excitation level are described

The NUMEN heavy ion multidetector for a complementary approach to the neutrinoless double beta decay

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 will be on the challenging experimental apparatus currently under construction in order to fulfil the requirements of the NUMEN experiment. The overall structure of the technological improvement to the cyclotron, along with the newly developed detection systems required for tracking and identifying the reaction products and their final excitation level are described