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Nanosecond pulsed proton beam: Upgrade of the accelerator-based neutron facility HiSPANOS at CNA (Spain)
Get PDFThe 3 MV Tandem Pelletron accelerator at the Spanish Accelerator Laboratory (CNA) has been recently upgraded to produce pulsed ion beams for neutron Time-Of-Flight (TOF) measurements. The upgrade has consisted of two actions: a pulsing system installed at the low energy part of the Tandem accelerator and a new line fully equipped. The pulsing system provides approximately one nanosecond pulse width of protons with variable repetition rates from kHz down to MHz. The new line is equipped with conventional devices and a pick-up for timing measurements with high resolution. The properties of the whole system have been tested under various working conditions and they are described in some detail
Conceptual design of accelerator driven systems with light ion beams
Get PDFThe superior energy efficiency of light ion beams instead of proton beams for energy production in accelerator driven systems (ADS) is demonstrated. The energy efficiency is characterized by the energy gain calculated as the ratio of the energy released in the target to the energy spent for the beam acceleration. The energy deposited in the target is obtained via Geant4 simulation. A method to calculate the energy spent for the beam acceleration by scaling from the data for a reference beam is presented. The influence of the target structure on the energy efficiency of 0.5 - 4 GeV proton beams and 0.25 1 AGeV light ion beams is studied. The target consists of rods with different composition (metal, oxide, carbide) and different levels of enrichment in order to implement the target with a criticality coefficient keff of 0.96 - 0.97, which ensure safe operation. The influence of the rod dimensions, the coolant and converter on the neutron spectrum and energy released are analysed
The upgrade of the ALICE Inner Tracking System at the CERN LHC
Get PDFIn 2021, for the third run of the CERN Large Hadron Collider (LHC), Pb–Pb collisions will be performed at a centre-of-mass energy per nucleon of √sNN = 5.5 TeV, with an integrated luminosity of 6 × 1027 cm−2s−1 and at an
unprecedented interaction rate of 50 kHz. To fulfil the requirements of its physics program for Run 3 the ALICE experiment at LHC is preparing a major upgrade during the Long Shutdown 2 of LHC in 2019-2020. One of the key elements of the program, is the construction of a new ultra-light and high-resolution Inner Tracking System (ITS) to enhance the determination of the distance of closest approach to the primary vertex, the tracking efficiency at low transverse momenta, and the read-out rate capabilities, with respect to what can be achieved with the current detector. The ITS will consist of seven cylindrical and concentric layers equipped with silicon Monolithic Active Pixel Sensors (MAPS) with a pixel size of the order of 30×30 μm2 built with the TowerJazz 0.18 μm CMOS Imaging process. The ITS upgrade collaboration has finished the R&D of the detector components and has started the production phase
Results of the 1 tonne × year WIMP search with XENON1T
Get PDFAstronomical and cosmological observations indicate that a large amount of the energy content of the Universe is made of dark matter. The most promising dark matter candidates are the so-called WIMPs (Weakly Interacting Massive Particles). The XENON project, at the Gran Sasso National Laboratory (LNGS), consists of a double-phase time projection chamber (TPCs) using ultrapure liquid Xenon as both target and detection medium for dark matter particle
interactions. The WIMPs can be indeed detected via their elastic scattering off Xenon nuclei. The XENON Collaboration is now running the XENON1T experiment, the first ton scale liquid Xenon based TPC, with an active mass inside the TPC of about 2 t. Data were collected in a live time of 279 days of dark matter search up to February 2018. The detector presents the lowest electronic recoil background ever obtained in a dark matter experiment: (82+5
−3(sys) ± 3(stat)) events/(t × yr × keVee). The results allowed to set the most stringent exclusion limits on the
spin-independent WIMP-nucleon interaction cross section for WIMP masses above 6 GeV/c2, with a minimum of 4.1 × 10−47 cm2 for 30 GeV/c2 WIMP mass at 90% confidence level
Investigation of nuclear cluster phenomenology with the relativistic EDF approach
Get PDFRelativistic energy density functionals (REDF) allowed to bring these last years a complementary understanding to the nuclear clustering phenomena. Three steps forwards are reported: i) localisation as a function of the nucleonic
quantum numbers, indicating related cluster effects over the nuclear chart; ii) detailed comparisons with experimental data available on spectroscopy of light nuclei such as 20Ne and 12C and iii) investigation of pairing and quarteting effects within the REDF
Isospin transport phenomena in semiperipheral heavy ion collisions at Fermi energies
Get PDFThe FAZIA collaboration started its physics program in 2015 with a setup consisting of four complete blocks (ISOFAZIA experiment). Results concerning isospin transport phenomena and QP fission for the systems 80Kr + 40,48Ca at 35 MeV/nucleon are discussed. A comparison with the prediction of the AMD model is also presented
Baryon time-like form factors at BESIII
Get PDFThe BESIII experiment, operating at the Beijing e+e− collider BEPCII, has collected large data sets at center-of-mass energies between 2.0 and 4.6 GeV allowing the measurement of baryon electromagnetic form factors in the time-like region employing different experimental techniques. An overview of the BESIII results on proton, hyperon form factors are presented together with future perspectives
Searching for the double γ-decay of the X(17) particle
Get PDFThe e−e+ decay of the candidate new particle X(17) has already been confirmed by previous experiments. However, theoretical models give different predictions for the spin and the parity of this particle. The double γ-decay process
could be an appropriate probe to shed light on such properties. Thus, for the first time, we searched for the γγ decay of X(17) created in nuclear transitions. In this
paper, we report preliminary results of two experiments on the Jπ = 0− → 0+ transition in 4He
FOOT: FragmentatiOn Of Target Experiment
Get PDFThe main goal of the FOOT (FragmentatiOn Of Target) experiment is the measurement of the differential cross sections as a function of energy and direction of the produced fragments in the nuclear interaction between a ion beam (proton, helium, carbon, ...) and different targets (proton, carbon, oxygen, ...). Depending on the beam energy, the purpose of the measurements is twofold: in the [150-400] MeV/u range, the data will be used to evaluate the side effects of the nuclear fragmentation in the hadrontherapy treatment, while in the [700-1000] MeV/u range it will be used to optimize the shielding of spaceships for long term space missions. The experiment has been funded by the INFN since September 2017 and it is currently in the construction phase. An overview of the detector, of the results obtained in several beam tests and of the expected performances will be presented
Measurements of lepton universality at LHCb
Get PDFLepton universality violation would represent a signal of physics beyond the Standard Model. Anomalies have been observed in the measurement of the branching ratios of semileptonic decays of beauty mesons in third-generation leptons. This contribution reports on the measurements of the observable R(D∗−) = B(B0 → D∗−τ +ντ )/B(B0 → D∗−μ+νμ) and R(J/ψ) = B(B+ c → J/ψτ +ντ )/B(B+ c → J/ψμ+νμ) performed at LHCb with data collected during the Run 1 of the LHC