Clustering in low density nuclear matter has been investigated using the NIMROD multidetector at Texas A&M University. Thermal coalescence modes were employed to extract densities, ρ, and ...temperatures, T, for evolving systems formed in collisions of 47A MeV (40)Ar+(112)Sn, (124)Sn and (64)Zn+(112)Sn, (124)Sn. The yields of d, t, (3)He, and (4)He have been determined at ρ=0.002 to 0.03 nucleons/fm(3) and T=5 to 11 MeV. The experimentally derived equilibrium constants for α particle production are compared with those predicted by a number of astrophysical equations of state. The data provide important new constraints on the model calculations.
Pulse shape discrimination with fast digitizers Cester, D.; Lunardon, M.; Nebbia, G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
06/2014, Letnik:
748
Journal Article
Recenzirano
The pulse shape discrimination (PSD) between neutrons and gamma rays in liquid scintillators is studied by using the charge integration method with fast digitizers having different technical ...characteristics. The use of the Figure of Merit (FoM) to verify the PSD capability is discussed. The dependence of the FoM on the digitizer sampling rate and resolution is experimentally determined. The effects due to the type of source and the irradiation geometry are also evidenced and discussed.
Measuring the variability of incoming neutrons locally would be usefull for the cosmic‐ray neutron sensing (CRNS) method. As the measurement of high energy neutrons is not so easy, alternative ...particles can be considered for such purpose. Among them, muons are particles created from the same cascade of primary cosmic‐ray fluxes that generate neutrons at the ground. In addition, they can be easily detected by small and relatively inexpensive detectors. For these reasons they could provide a suitable local alternative to incoming corrections based on remote neutron monitor data. The reported measurements demonstrated that muon detection system can detect incoming cosmic‐ray variations locally. Furthermore the precision of this measurement technique is considered adequate for many CRNS applications.
Plain Language Summary
The measurement of the variability of the incident neutron flux is of fundamental importance for the cosmic‐ray neutron sensing technique. This type of measurement is not easy to use to have local and instantaneous values. For this reason in this work it is reported how this type of information can be obtained through the measurement of the flux of cosmic muons, which are correlated with the flux of cosmic neutrons. This type of measurement, being easier to perform, allows you to have a local and real time value in a very simple way.
Key Points
Incoming correction in cosmic‐ray neutron sensing observations based on local muon measurements at ground
In-medium binding energies and Mott points for d, t, 3He and α clusters in low-density nuclear matter have been determined at specific combinations of temperature and density in low-density nuclear ...matter produced in collisions of 47A MeV 40Ar and 64Zn projectiles with 112Sn and 124Sn target nuclei. The experimentally derived values of the in-medium modified binding energies are in good agreement with recent theoretical predictions based upon the implementation of Pauli blocking effects in a quantum statistical approach.
Radio Pharmaceutical Therapy (RPT) comes forth as a promising technique to treat a wide range of tumors while ensuring low collateral damage to nearby healthy tissues. This kind of cancer therapy ...exploits the radiation following the decay of a specific radionuclide to deliver a lethal dose to tumor tissues. In the framework of the ISOLPHARM project of INFN, 111Ag was recently proposed as a promising core of a therapeutic radiopharmaceutical. In this paper, the production of 111Ag via neutron activation of 110Pd-enriched samples inside a TRIGA Mark II nuclear research reactor is studied. The radioisotope production is modeled using two different Monte Carlo codes (MCNPX and PHITS) and a stand-alone inventory calculation code FISPACT-II, with different cross section data libraries. The whole process is simulated starting from an MCNP6-based reactor model producing the neutron spectrum and flux in the selected irradiation facility. Moreover, a cost-effective, robust and easy-to-use spectroscopic system, based on a Lanthanum Bromo-Chloride (LBC) inorganic scintillator, is designed and characterized, with the aim of using it, in the future, for the quality control of the ISOLPHARM irradiated targets at the SPES facility of the Legnaro National Laboratories of INFN. natPd and 110Pd-enriched samples are irradiated in the reactor main irradiation facility and spectroscopically characterized using the LBC-based setup and a multiple-fit analysis procedure. Experimental results are compared with theoretical predictions of the developed models, showing that inaccuracies in the available cross section libraries prevent an accurate reproduction of the generated radioisotope activities. Nevertheless, models are normalized to our experimental data allowing for a reliable planning of the 111Ag production in a TRIGA Mark II reactor.
•111Ag proposed in ISOLPHARM-INFN project as a promising core of radiopharmaceutical.•Temporary 111Ag production via neutron activation inside a TRIGA Mark II reactor.•Spectroscopic characterization of the production with a dedicated LBC-based setup.•Monte Carlo model and benchmark with experimental data to plan the 111Ag production.•Future 111Ag production with high-specific activity at the Italian SPES-ISOL facility.
Accelerator-based techniques with electromagnetic mass separation are considered among the most innovative and promising strategies to produce non-conventional radionuclides for nuclear medicine. ...Such approach was successfully used at CERN, where the dedicated MEDICIS facility was built, and at TRIUMF, where the ISAC radioactive beam facility was used to produce unconventional α-emitters. In such framework, the Legnaro National Laboratories of the Italian Institute of Nuclear Physics (INFN-LNL) proposed the ISOLPHARM project (ISOL technique for radioPHARMaceuticals), which will exploit radionuclides producible with the SPES (Selective Production of Exotic Species) ISOL (Isotope Separation On-Line) facility to develop novel radiopharmaceuticals. The ISOL technique utilizes the irradiation with a primary beam of particles/nuclei of a production target where radionuclides are produced. A radioactive ion beam is subsequently extracted from the production target unit, and transported up to an analyzing magnet, where non-isobaric contaminants are filtered out. The so-obtained purified radioactive beam is dumped onto an implantation substrate, referred as collection target. Then, the desired nuclides can be chemically harvested from the collected isobars, and the isotopically pure atom collection can be employed to radiolabel high specific activity radiopharmaceuticals. Metallic deposition targets in the form of coated metal foils were mostly used at TRIUMF and CERN. At ISOLPHARM, a different approach is under investigation which foresees the use of soluble cold-pressed collection targets, possibly facilitating the chemical purification process of the collected radionuclides. In this study, the production and characterization of some of the ISOLPHARM collection targets is presented, in particular, soluble salts (NaCl and NaNO3) and organic materials widely used for pharmaceutical tablets production are considered. All such materials proved to be potentially suitable as collection targets, since solid samples were easily produced and resulted compatible with the vacuum conditions required for the ion implantation process. Furthermore, some of the selected substrates were used for proof-of-concept deposition tests with stable silver, to prove their suitability as ISOLPHARM deposition substrates for silver-111, a promising candidate for radiotherapy. Such tests highlighted possible scenarios useful for the development of new alternative materials, as the use of insoluble organic targets.
•ISOL based techniques for the production of medical radionuclides require the use of an implantation target.•Generally, implantation targets are metallic foil, ISOLPHARM at INFN-LNL proposes saline or organic substrates.•NaCl, NaNO3, cellulosic and dextrates substrates were produced by direct compression.•All samples were characterized in terms of density, mechanical strength, disaggregation and vacuum compatibility.•Implantation depth calculations and tests with the deposition of Ag + ions were performed.
Here, we report about the synthesis of Cobalt‐Copper (CC) mixed oxides prepared by electrodeposition and thermal annealing, and coated with PEDOT:PSS (CCP) for supercapacitor electrodes. The ...electrodes’ morphology and electrochemical performance were investigated by combining XRD, XPS, SEM, cyclic voltammetry, and galvanostatic charge/discharge tests. The initial capacity of the CC electrode was 26 mAh/g at a scan rate of 5 mV/s with a coulombic efficiency of 92 %. The CC electrode featured a capacity retention of 81 % at a constant current density of 1 A/g after 5000 cycles. CCP electrodes slightly reduced the specific capacity but increased both coulombic efficiency and cyclic stability. CCP1 electrode featured a specific capacity of 21 mAh/g at 5 mV/s scan rate with better coulombic efficiency 95 % along with capacity retention of 92.3 % over 5000 cycles. Increasing the amount of PEDOT:PSS lowered the CC electrodes’ specific capacity, but significantly improved the capacity retention up to 100 %.
The effect of PEDOT:PSS on the cyclic stability of cobalt‐copper mixed oxides synthesized by electrochemical deposition has been studied. Electrodes containing PEDOT:PSS exhibited a capacity retention that increased with the amount of PEDOT:PSS, from 92 % up to 100 %. Cobalt‐copper mixed oxides electrode retained only 81 % of its initial capacity after 5000 cycles. Increasing PEDOT:PSS significantly improved the cyclic stability and capacity retention after 5000 cycles up to 100 %.
In this work we present the characterization of a large area 200 mm ×200 mm EJ-444 scintillation detector to be used for monitoring gross alpha and beta activity in tap water plants. Specific tests ...were performed in order to determine the best setup to read-out the light from the detector side. The possibility to stack many detectors and get a compact device with total active area of the order of 1 m 2 has been explored. Alpha/beta discrimination, efficiency and homogeneity tests were carried out with alpha and beta sources. Background from ambient radioactivity was measured as well. Alpha/beta real-time monitoring in drinking water is a goal of the EU project TAWARA_RTM.
A low cost 2/3 of 4π detector for the study of Ps decay Pino, F.; Fontana, C.L.; Lunardon, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2019, Letnik:
942
Journal Article
Recenzirano
Odprti dostop
A large area low-cost detector for detailed studies of ortho-Positronium formation and decay is being designed. The detector will be made of four modules each consisting of a thin slab of YAP(Ce) ...scintillator read out by a multi-anode flat panel photomultiplier tube. The proposed configuration will provide a position sensitive detector capable of recording, on an event-by-event basis, both the 2γ and the 3γ decay channels, for immediate information on the 2γ/3γ ratio. It will as well provide a 3D density distribution of the decay vertexes, thus enabling angular and velocity distribution measurements. In this paper we present the results of measurements performed on one module of the detector using conventional electronics, as well as Monte Carlo simulations on the performances of the system. Using a series of laboratory gamma sources we deduced values of energy and spatial resolution.
•Low-cost detector for detailed studies of ortho-Positronium formation.•YAP:Ce slap coupled to a multi-anode photomultiplier as position sensitive detector.•Center-of-mass based method to reconstruct the position of the photon interaction.•Spatial and energy resolution studies of a position sensitive detector.•Distribution of photon interaction points by Monte Carlo simulations.
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