Search results for "BEAM"
showing 10 items of 2126 documents
Search for Magnetic Monopoles and Stable High-Electric-Charge Objects in 13 Tev Proton-Proton Collisions with the ATLAS Detector
2020
We thank CERN for the very successful operation of the LHC, aswell as the support staff fromour institutionswithout whom ATLAS could not be operated efficiently. We acknowledge the support of ANPCyT, Argentina; YerPhI, Armenia; ARC, Australia; FWF, BMWFW, Austria; ANAS, Azerbaijan; SSTC, Belarus; CNPq, FAPESP, Brazil; NSERC, CFI, NRC, Canada; CERN; CONICYT, Chile; CAS, NSFC, MOST, China; COLCIENCIAS, Colombia; VSC CR, MSMT CR, MPO CR, Czech Republic; DNSRC, DNRF, Denmark; IN2P3-CNRS, CEA-DRF/IRFU, France; SRNSFG, Georgia; MPG, HGF, BMBF, Germany; GSRT, Greece; RGC, Hong Kong SAR, Hong Kong China; Benoziyo Center, ISF, Israel; INFN, Italy; JSPS, MEXT, Japan; JINR; CNRST, Morocco; NWO, Nether…
Steering of a Sub-GeV electron beam through planar channeling enhanced by rechanneling
2014
We report the observation of efficient steering of a 855 MeV electron beam at MAMI (MAinzer MIkrotron) facilities by means of planar channeling and volume reflection in a bent silicon crystal. A $30.5\text{ }\text{ }\ensuremath{\mu}\mathrm{m}$ thick plate of (211) oriented Si was bent to cause quasimosaic deformation of the (111) crystallographic planes, which were used for coherent interaction with the electron beam. The experimental results are analogous to those recorded some years ago at energy higher than 100 GeV, which is the only comparable study to date. Monte Carlo simulations demonstrated that rechanneling plays a considerable role in a particle's dynamics and hinders the spoiling…
Six-dimensional measurements of trains of high brightness electron bunches
2015
Trains of ultrashort electron pulses with THz repetition rate, so-called comblike beams, are assuming an ever growing interest in plasma-based acceleration. In particle-driven plasma wakefield acceleration (PWFA), a train of driver bunches with separation of the order of plasma wavelength, i.e., 300 μm, resonantly excites a plasma wake, which accelerates a trailing witness bunch, injected at the accelerating phase. Comblike beams have great potentialities in different fields of applications. In particular, radiation sources, such as free-electron lasers and THz radiation, take advantage from the possibility to tailor electron beams modulated both in time and energy, to customize emission ba…
Evaluation of radiation stability of electron beam irradiated Nafion® and sulfonated poly(ether ether ketone) membranes
2022
Proton exchange membranes (PEM), which have been commonly used in fuel cells have raised interest for the application in harsh environments involving ionizing radiation. Therefore, radiation stability and ability to sustain their functionality under the radiation environment are of great interest. Within this study, electron beam irradiation in dose range from 50 to 500kGy was used to evaluate the effects of radiation on the physico-chemical and mechanical properties of two types of PEM: commercial Nafion®117 and sulfonated poly(ether-ether-ketone) (SPEEK) with high degree of sulfonation (DS = 0.75±0.5). SPEEK membrane presented higher mechanical and thermal stability compared to that of Na…
Measurement of the SMC muon beam polarisation using the asymmetry in the elastic scattering off polarised electrons
2000
A muon beam polarimeter was built for the SMC experiment at the CERN SPS, for beam energies of 100 and 190 GeV. The beam polarisation is determined from the asymmetry in the elastic scattering off the polarised electrons of a ferromagnetic target whose magnetisation is periodically reversed. At muon energies of 100 and 190 GeV the measured polarisation is P-mu = -0.80 +/- 0.03 (stat.) +/- 0.02 (syst.) and P-mu = - 0.797 +/- 0.011 (stat.) +/- 0.012 (syst.), respectively. These results agree with measurements of the beam polarisation using a shape analysis of the decay positron energy spectrum. (C) 2000 Elsevier Science B.V. All rights reserved.
Electron and photon performance measurements with the ATLAS detector using the 2015-2017 LHC proton-proton collision data
2019
This paper describes the reconstruction of electrons and photons with the ATLAS detector, employed for measurements and searches exploiting the complete LHC Run 2 dataset. An improved energy clustering algorithm is introduced, and its implications for the measurement and identification of prompt electrons and photons are discussed in detail. Corrections and calibrations that affect performance, including energy calibration, identification and isolation efficiencies, and the measurement of the charge of reconstructed electron candidates are determined using up to 81 fb−1 of proton-proton collision data collected at √s=13 TeV between 2015 and 2017.
The TRAPSENSOR facility: an open-ring 7 tesla Penning trap for laserbased precision experiments
2019
APenning-trap facility for high-precision mass spectrometry based on a novel detection method has been built. This method consists in measuring motional frequencies of singly-charged ions trapped in strong magnetic fields through the fluorescence photons from laser-cooled 40Ca+ ions, to overcome limitations faced in electronic single-ion detection techniques. The key element of this facility is an open-ring Penning trap coupled upstream to a preparation Penning trap similar to those used at Radioactive Ion Beam facilities. Here we present a full characterization of the trap and demonstrate motional frequency measurements of trapped ions stored by applying external radiofrequency fields in r…
Development of a New Clusterization Method for the GEM-TPC Detector
2022
The Facility for Antiproton and Ion Research FAIR, in Darmstadt Germany, will be one of the largest accelerator laboratories worldwide. The Superconducting FRagment Separator (Super-FRS)* is one of its main components. The Super-FRS can produce, separate and deliver high-energy radioactive beams with intensities up to 1e11 ions/s, covering projectiles from protons up to uranium and it can be used as an independent experimental device. The Gas Electron Multiplier-based Time Projection Chambers (GEM-TPC) in twin configuration is a newly developed beam tracking detector capable of providing spatial resolution of less than 1 mm with a tracking efficiency close to 100% at 1 MHz counting rate. Th…
Effect of electron-beam irradiation on structure of ultra high molecular weight polyethylene used in medical implants
2004
Określono wpływ napromieniania strumieniem elektronów dawką równoważną stosowanej w praktyce podczas sterylizacji radiacyjnej endoprotez chirurgicznych (26 kGy) oraz dwukrotnie większą (2 . 26 kGy) na zmianę struktury PE-UHMW o nazwie handlowej „,Chirulen 1120”' (tabela 1) służącego do otrzymywania panewek endoprotez biodrowych. Metodą FT-IR zbadano zmiany strukturalne polimeru, stwierdzając głównie występowanie skutków jego utlenienia (wzrost udziału grup karbonylowych typu ketonowego, estrowego i nadestrowego, grup hydroksylowych oraz winylowych) (rys. 1). Metodą GPC stwierdzono, że napromienianie powoduje także częściową degradację makrocząsteczek (zmniejszenie ciężaru cząsteczkowego o j…
Energy efficiency in wireless networks
2013
Tämä pro gradu -työ on sekundääritutkimuksena tehty kirjallisuuskatsaus energiatehokkuuden tarkastelusta langattomissa verkoissa. Työssä tarkastellaan erilaisia mobiiliverkkojen energiansäästömahdollisuuksia. Pääpaino työssä on suunnattu erityisesti 3G ja LTE -verkkoihin, kuitenkin eksoottisempiakaan verkkoja unohtamatta. Työ alkaa erilaisten mobiiliverkkojen energiansäästösyiden ja tutkimusmotivaattoreiden tunnistamisella ja jatkuu langattomien verkkojen energian kulutuksen jaotuksella, sekä erilaisten energiansäästömahdollisuuksien vertailuilla. Työn empiirisessä osassa nostetaan lisäksi esille lyhyt Octave-simulaatio kollaboroivan mobiilipilven noodien energiansa…