140 research outputs found
Resuming elective surgical activity after the COVID-19 wave: what the patients need to know
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus causing coronavirus disease 2019 (COVID-19), infected more than four million people during the first months of 2021, and Italy was reported to have the highest death toll per million population at the beginning of May2. While there is no consensus on the treatment of the disease yet, understanding how the virus and its transmission will behave in the future is a cardinal priority for planning the re-establishment of routine healthcare services, such as surgery, in view of preventing indirectly COVID-19-related deaths due to undelivered care and lack of adequate treatment. Sadly, elective surgery on patients with perioperative SARS-CoV-2 infection, has shown increased mortality risk, therefore increasing anxiety among the population waiting for surgical interventions, as most of the elective activity was suspended due to COVID-19
outbreak
Tracking system based on GEM chambers
GEM chambers are becoming one of the best technology for charge particle tracking fulfilling the challenging requirements of modern experiment at intermediate and high energy, including Parity Violation Electron Scattering experiments. GEM tracker combines high spatial resolution, large active area and pretty good tolerance to high particle flux, at reasonable cost. GEM technology is shortly
presented and a specific application for the high luminosity experiments in Hall A at JLab is discussed. Some alternatives to the GEM are also addressed
The GRAAL high resolution BGO calorimeter and its energy calibration and monitoring system
We describe the electromagnetic calorimeter built for the GRAAL apparatus at
the ESRF. Its monitoring system is presented in detail. Results from tests and
the performance obtained during the first GRAAL experiments are given. The
energy calibration accuracy and stability reached is a small fraction of the
intrinsic detector resolution.Comment: 19 pages, 14 figures, submitted to Nuclear Instruments and Method
Deuteron photo-disintegration with polarised photons in the energy range 30 - 50 MeV
The reaction d(\vec\gamma,np) has been studied using the tagged and polarised
LADON gamma ray beam at an energy 30 - 50 MeV to investigate the existence of
narrow dibaryonic resonances recently suggested from the experimental
measurements in a different laboratory. The beam was obtained by Compton
back-scattering of laser light on the electrons of the storage ring ADONE.
Photo-neutron yields were measured at five neutron angle \vartheta_n = 22,
55.5, 90, 125 and 157 degrees in the center of mass system.Our results do not
support the existence of such resonances.Comment: 16 pages, Latex, 22 figures, 1 table. Nucl. Phys. A to appea
64Cu production by 14 MeV neutron beam
64Cu is an emerging radionuclide of great interest in personalized nuclear medicine. It is produced by a cyclotron via the reaction 64Ni(p,n)64Cu. This production method increased during the last decades, because small biomedical cyclotrons can be easily installed close to the nuclear medicine department of a hospital. As a matter of fact, 64Ni is a very expensive target material. For this reason, an alternative 64Cu production method was investigated at ENEA by using the quasi-monochromatic 14 MeV fusion neutron beam made available at the Frascati Neutron Generator (FNG) located at the ENEA - Frascati Research Center. In particular, two nuclear reactions were studied: 65Cu(n,2n)64Cu and 64Zn(n,p)64Cu. The radiochemical analysis of the activated samples was performed at the ENEA-NMLNWM laboratory located in ENEA-Casaccia Research Center. The activity measurements were carried out at the ENEA-INMRI, located in the ENEA-Casaccia Research Center, with high metrological level conditions and by assuring their traceability to the 64Cu primary activity standard here developed and maintained. A prediction of the 64Cu production by means of the high-brilliance 14 MeV neutron source named Sorgentina is also discussed
Differential cross section measurement of eta photoproduction on the proton from threshold to 1100 MeV
The differential cross section for the reaction p(gamma, eta p) has been
measured from threshold to 1100 MeV photon laboratory energy. For the first
time, the region of the S11(1535) resonance is fully covered in a
photoproduction experiment and allows a precise extraction of its parameters at
the photon point. Above 1000 MeV, S-wave dominance vanishes while a P-wave
contribution is observed whose nature will have to be clarified. These high
precision data together with the already measured beam asymmetry data will
provide stringent constraints on the extraction of new couplings of baryon
resonances to the eta meson.Comment: 10 pages, 5 figures, submitted to Phys. Letters B. Typos corrected.
Some more information on the S11(1535) parameter
Precise Measurement of Sigma Beam Asymmetry for Positive Pion Photoproduction on the Proton from 800 to 1500 Mev
The Sigma beam asymmetry for positive pion photoproduction on the proton has
been measured over an angular range of 40-170 deg at photon energies from 0.8
to 1.5 GeV. The resulting data set includes 237 accurate points, 136 of these
belonging to an almost unexplored domain above 1.05 GeV. Data of such high
precision provide severe constraints for partial wave analyses. The influence
of this experiment on the GW multipole analysis is demonstrated. Significant
changes are found in multipoles connected to the S31(1620) and P13(1720)
resonances. Comparisons using the MAID analysis are also presented.Comment: 11 pages, 4 eps figures. to be published in Physics Letters
Measurement of eta photoproduction on the proton from threshold to 1500 MeV
Beam asymmetry and differential cross section for the reaction gamma+p->eta+p
were measured from production threshold to 1500 MeV photon laboratory energy.
The two dominant neutral decay modes of the eta meson, eta->2g and eta->3pi0,
were analyzed. The full set of measurements is in good agreement with
previously published results. Our data were compared with three models. They
all fit satisfactorily the results but their respective resonance contributions
are quite different. The possible photoexcitation of a narrow state N(1670) was
investigated and no evidence was found.Comment: 18 pages, 14 figures, 4 tables Submitted to EPJ
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