Search results for "beams"
showing 10 items of 268 documents
Experimental Tests and FEM Model for SFRC Beams under Flexural and Shear Loads
2008
The complete load-vs-displacement curves obtained by four-point-bending tests on Steel Fiber Reinforced Concrete (SFRC) beams are predicted by using a nonlinear finite element code based on the Modified Compression Field Theory (MCFT) and the Disturbed Stress Field Model (DSFM) suitably adapted for SFRC elements. The effect of fibers on the shear-flexure response is taken into account, mainly incorporating tensile stress-strain analytical relationship for SFRC. The numerical results show the effectiveness of the model for prediction of the behavior of the tested specimens reinforced with light amount of stirrups or with fibers only. © 2008 American Institute of Physics.
Measurement of branching fractions and charge asymmetries for exclusive B decays to charmonium
2005
We report measurements of branching fractions and charge asymmetries of exclusive decays of neutral and charged B mesons into two-body final states containing a charmonium state and a light strange meson. The charmonium mesons considered are J/Psi, Psi(2S) and Chi_c1, and the light meson is either K or K*. We use a sample of about 124 million BBbar events collected with the BABAR detector at the PEP-II storage ring at the Stanford Linear Accelerator Center.
Monte Carlo simulations of high-energy electron beams : model validation and dose calculations
2017
Komponenttisäteilytykseen valjastetusta Varian Clinac 2100 C/D -lineaarikiihdyttimestä luotiin Monte Carlo -menetelmiä hyödyntävä simulaatiomalli. Malli luotiin aineen ja säteilyn vuorovaikutuksien laskennalliseen mallintamiseen tarkoitettua Geant4 -ohjelmointityökalupakettia käyttäen. Mallin kyky ennustaa mittaustuloksia kiihdyttimen tuottamasta 20 MeV:in elektronisuihkusta todennettiin laskettuja ja mitattuja tuloksia vertailemalla, ja mallin jatkokehityksen kannalta tärkeimmät toimenpiteet määriteltiin. Lisäksi arvioitiin mallin ennustamaa absorpoitunutta annosta vesi- ja piifantomeissa, sekä laskettiin viitearvo absorpoituneen annoksen ja elektronivuon suhteelle. Lasketut annosprofiilit…
Spatial beam cleaning in quadratic nonlinear medium
2018
We show experimentally that a laser beam scrambled by propagation in a short segment of multimode fiber may be cleaned by the nonlinear propagation in KTP cristal with type-II second-harmonic generation.
The next-generation liquid-scintillator neutrino observatory LENA
2012
We propose the liquid-scintillator detector LENA (Low Energy Neutrino Astronomy) as a next-generation neutrino observatory on the scale of 50 kt. The outstanding successes of the Borexino and KamLAND experiments demonstrate the large potential of liquid-scintillator detectors in low-energy neutrino physics. LENA's physics objectives comprise the observation of astrophysical and terrestrial neutrino sources as well as the investigation of neutrino oscillations. In the GeV energy range, the search for proton decay and long-baseline neutrino oscillation experiments complement the low-energy program. Based on the considerable expertise present in European and international research groups, the …
Precision mass measurements of neutron-rich nuclei between N=50 and 82
2012
Our knowledge of binding energies of neutron-rich nuclei has experienced a major revision during the last five years due to the introduction of Penning-trap based mass measurements. New mass values for nearly 300 nuclides produced in fission with uncertainties of 10 keV or less have become available. The data produced at three Penning trap facilities at Jyvaskyla, CERN-ISOLDE and Argonne cover all isotopic chains from Ni to Pr, except iodine. In this talk some of this data is reviewed and applied using the mass differentials such as two-neutron binding energy and odd-even staggering to probe their sensitivity on changes in nuclear structure and on the strength of the N=82 shell gap and asso…
Dissipative connections of rc frames with prefabricated steel-trussed-concrete beams
2020
In the last thirty years, Hybrid Steel-Trussed Concrete Beams (HSTCBs) have been widely used in civil and industrial constructions and, therefore, their mechanical performance must be evaluated with the aim of guaranteeing adequate dissipation of the seismic energy particularly in the beam-to-column joints. However, one of the most frequent peculiarities of HSTCBs is that of using their own steel joist to cover large spans with reduced depth and, in the case of traditional beam-to-column connections, this requires large amount of steel reinforcement inside the panel zone, often made with large diameter rebars. These characteristics make both the panel zone and the beam end potentially vulne…
The importance of kinematic twists and genuine saturation effects in dijet production at the Electron-Ion Collider
2021
We compute the differential yield for quark anti-quark dijet production in high-energy electron-proton and electron-nucleus collisions at small $x$ as a function of the relative momentum $\boldsymbol{P}_\perp$ and momentum imbalance $\boldsymbol{k}_\perp$ of the dijet system for different photon virtualities $Q^2$, and study the elliptic and quadrangular anisotropies in the relative angle between $\boldsymbol{P}_\perp$ and $\boldsymbol{k}_\perp$. We review and extend the analysis in [1], which compared the results of the Color Glass Condensate (CGC) with those obtained using the transverse momentum dependent (TMD) framework. In particular, we include in our comparison the improved TMD (ITMD…
Collectivity in ${}^{\mathrm{196,198}}$Pb isotopes probed in Coulomb-excitation experiments at REX-ISOLDE
2017
The neutron-deficient ${}^{\mathrm{196,198}}$Pb isotopes have been studied in Coulomb-excitation experiments employing the Miniball γ-ray spectrometer and radioactive ion beams from the REX-ISOLDE post-accelerator at CERN. The reduced transition probabilities of the first excited 2+ states in 196Pb and 198Pb nuclei have been measured for the first time. Values of $B(E2)={18.2}_{-4.1}^{+4.8}$ W.u. and $B(E2)={13.1}_{-3.5}^{+4.9}$ W.u., were obtained, respectively. The experiment sheds light on the development of collectivity when moving from the regime governed by the generalised seniority scheme to a region, where intruding structures, associated with different deformed shapes, start to com…
Rate capability of a cryogenic stopping cell for uranium projectile fragments produced at 1000 MeV/u
2016
At the Low-Energy Branch (LEB) of the Super-FRS at FAIR, projectile and fission fragments will be produced at relativistic energies, separated in-flight, energy-bunched, slowed down and thermalized in a cryogenic stopping cell (CSC) filled with ultra-pure He gas. The fragments are extracted from the stopping cell using a combination of DC and RF electric fields and gas flow. A prototype CSC for the LEB has been developed and successfully commissioned at the FRS Ion Catcher at GSI. Ionization of He buffer gas atoms during the stopping of energetic ions creates a region of high space charge in the stopping cell. The space charge decreases the extraction efficiency of stopping cells since the …