Search results for "Accelerator physics"
showing 10 items of 1294 documents
New high-sensitivity searches for neutrons converting into antineutrons and/or sterile neutrons at the HIBEAM/NNBAR experiment at the European Spalla…
2021
Abstract The violation of baryon number, B , is an essential ingredient for the preferential creation of matter over antimatter needed to account for the observed baryon asymmetry in the Universe. However, such a process has yet to be experimentally observed. The HIBEAM/NNBAR program is a proposed two-stage experiment at the European Spallation Source to search for baryon number violation. The program will include high-sensitivity searches for processes that violate baryon number by one or two units: free neutron–antineutron oscillation ( n → n ̄ ) via mixing, neutron–antineutron oscillation via regeneration from a sterile neutron state ( n → [ n ′ , n ̄ ′ ] → n ̄ ), and neutron disappearan…
A comparative study of the behaviour of silver, copper and nickel submitted to a constant high power flux density
2005
In this paper, we present a numerical simulation of three metal cathode (silver, copper and nickel) submitted to a constant flux power flux density ranging between and . The goal is to compare the interface evolution (vaporization and liquefaction rate, appearance time of liquid and vapour, energetic repartition) to predict the behaviour of the cathodes during an electric arc.
Production of titanium ion beams in an ECR ion source
2002
Abstract Intensive highly charged Ti ion beams were successfully produced in the 14 GHz ECR ion source at the Accelerator Laboratory, University of Jyvaskyla (JYFL). The Ti beams were produced using the MIVOC technique, i.e. by allowing the vapor of an organic compound containing titanium to diffuse into the ion source at room temperature. After optimizing the source parameters the intensity of the 48 Ti 11+ ion beam reached a value of 45 μA.
Positron Lifetime in Hostaphan
2006
Positron lifetime measurements in hostaphan RNK, used for encapsulation of Na positron sources, were performed. It was found that the parameter of positron lifetime spectra in hostaphan RNK differ markedly from those for other forms of polyethylene terephthalate. The maximum penetration depth of positrons from RNK hostaphan amounts 0.42 mm. The information gained in the present study is of great importance for experimenters using hostaphan RNK for encapsulation of positron sources.
Nonlinear beam self-cleaning in a coupled cavity composite laser based on multimode fiber
2017
International audience; We study a coupled cavity laser configuration where a passively Q-switched Nd:YAG microchip laser is combined with an extended cavity, including a doped multimode fiber. For appropriate coupling levels with the extended cavity, we observed that beam self-cleaning was induced in the multimode fiber thanks to nonlinear modal coupling, leading to a quasi-single mode laser output. In the regime of beam self-cleaning, laser pulse duration was reduced from 525 to 225 ps. We also observed a Q-switched mode-locked operation, where spatial self-cleaning was accompanied by far-detuned nonlinear frequency conversion in the active multimode fiber.
Neutron halos in the excited states of 12B
2018
The differential cross sections of the 11B(d,p) 12B reaction leading to formation of the 1+ ground state and the 0.95-MeV 2+, 1.67-MeV 2−, 2.62-MeV 1−, 2.72-MeV 0+, and 3.39-MeV 3− excited states of 12B are measured at Ed = 21.5 MeV. The analysis of the data is carried out within the coupled-reaction-channels method for the direct neutron transfer and the Hauser-Feshbach formalism of the statistical compound-nucleus model. The spectroscopic factors, asymptotic normalization coefficients, and rms radii of the last neutron in all states studied are deduced. The existence of the neutron halos in the 1.67-MeV 2− and 2.62-MeV 1− states is found, consistent with the earlier published data. New in…
The effective cross section for double parton scattering within a holographic AdS/QCD approach
2017
A first attempt to apply the AdS/QCD framework for a bottom-up approach to the evaluation of the effective cross section for double parton scattering in proton-proton collisions is presented. The main goal is the analytic evaluation of the dependence of the effective cross section on the longitudinal momenta of the involved partons, obtained within the holographic Soft-Wall model. If measured in high-energy processes at hadron colliders, this momentum dependence could open a new window on 2-parton correlations in a proton.
"fig4: proton dAu" of "Spectra and ratios of identified particles in Au+Au and d+Au collisions at sqrt(s_{NN})=200 GeV"
2020
proton dAu Invariant yields versus $p_T$
Measurement of the cosmic ray proton spectrum from 40 GeV to 100 TeV with the DAMPE satellite
2019
DAMPE satellite has directly measured the cosmic ray proton spectrum from 40 GeV to 100 TeV and revealed a new feature at about 13.6 TeV.
Measurements of the top quark branching ratios into channels with leptons and quarks with the ATLAS detector
2015
Measurements of the branching ratios of top quark decays into leptons and jets using events with t[bar over t] (top antitop) pairs are reported. Events were recorded with the ATLAS detector at the LHC in pp collisions at a center-of-mass energy of 7 TeV. The collected data sample corresponds to an integrated luminosity of 4.6 fb[superscript −1]. The measured top quark branching ratios agree with the Standard Model predictions within the measurement uncertainties of a few percent.