# Accelerator Physics

Πρόσφατες προσθήκες:
2022-05-24
06:41
 Design of a Very Low Energy Beamline for NA61/SHINE / Mussolini, Carlo Alberto (CERN ; JAI, UK) ; Burrows, Philip N (JAI, UK) ; Charitonidis, Nikolaos (CERN) ; Nagai, Yoshikazu (U. Colorado, Boulder) ; Zimmerman, Eric D (U. Colorado, Boulder) A new, low-energy beamline branch is currently under consideration for the H₂ beamline at the CERN North Area. This new branch would extend the capabilities of the current infrastructure enabling the study of particles in the very low, 1-13 GeV/c, momentum range. [...] Geneva : JACoW, 2021 - 4 p. - Published in : JACoW IPAC 2021 (2021) 4017-4020 Fulltext: PDF; In : 12th International Particle Accelerator Conference (IPAC 2021), Online, 24 - 28 May 2021, pp.4017-4020

2022-05-24
06:41
 Detection and Classification of Collective Beam Behaviour in the LHC / Coyle, Loic (Ecole Polytechnique, Lausanne ; CERN) ; Blanc, Frederic (Ecole Polytechnique, Lausanne) ; Buffat, Xavier (CERN) ; Krymova, Ekaterina (Ecole Polytechnique, Lausanne ; Zurich, ETH) ; Obozinski, Guillaume (Ecole Polytechnique, Lausanne ; Zurich, ETH) ; Pieloni, Tatiana (Ecole Polytechnique, Lausanne ; CERN) ; Schenk, Michael (Ecole Polytechnique, Lausanne ; CERN) ; Solfaroli Camillocci, Matteo (CERN) ; Wenninger, Jorg (CERN) Collective instabilities can lead to a severe deterioration of beam quality, in terms of reduced beam intensity and increased beam emittance, and consequently a reduction of the collider’s luminosity. It is therefore crucial for the operation of the CERN’s Large Hadron Collider to understand the conditions in which they appear in order to find appropriate mitigation measures. [...] Geneva : JACoW, 2021 - 4 p. - Published in : JACoW IPAC 2021 (2021) 4318-4321 Fulltext: PDF; In : 12th International Particle Accelerator Conference (IPAC 2021), Online, 24 - 28 May 2021, pp.4318-4321

2022-05-24
06:41
 A Mechanism for Emittance Growth Based on Non-Linear Islands in LHC / Maclean, Ewen H (CERN) ; Giovannozzi, Massimo (CERN) ; Persson, Tobias H B (CERN) ; Tomás García, Rogelio (CERN) Landau octupoles are used in the LHC to prevent coherent instabilities of the circulating beam. The reduction of their strength occurring during the energy ramp can transport particles in nonlinear islands to larger amplitude. [...] Geneva : JACoW, 2021 - 4 p. - Published in : JACoW IPAC 2021 (2021) 4082-4085 Fulltext: PDF; In : 12th International Particle Accelerator Conference (IPAC 2021), Online, 24 - 28 May 2021, pp.4082-4085

2022-05-21
06:07
 Forced Coupling Resonance Driving Terms / Wegscheider, Andreas (CERN) ; Tomás García, Rogelio (CERN) At the LHC, coupling is routinely measured using forced oscillations of the beam through excitation with an AC-dipole. The driving of the particle motion has an impact on the measurement of resonance driving terms. [...] Geneva : JACoW, 2021 - 4 p. - Published in : JACoW IPAC '21 (2021) 3646-3649 Fulltext: PDF; In : 12th International Particle Accelerator Conference (IPAC 2021), Online, 24 - 28 May 2021, pp.3646-3649

2022-05-21
06:07
 The impact of H$_2$ and N$_2$ on the material properties and secondary electron yield of sputtered amorphous carbon films for anti-multipacting applications / Fernández, H Moreno (CERN) ; Himmerlich, M (CERN) ; Costa Pinto, P (CERN) ; Coroa, J (CERN) ; Sousa, D (Nova U., Lisboa) ; Baris, A (CERN) ; Taborelli, M (CERN) Amorphous carbon thin films were prepared by direct current hollow cathode sputter deposition in Ar discharge with the injection of small amounts of H$_2$ and/or N$_2$. The influence of these additives on the film properties with particular focus on the application as a coating for electron cloud mitigation in particle accelerators is characterized by optical spectroscopy, X-ray photoelectron spectroscopy, and secondary electron yield (SEY) measurements. [...] 2021 - 10 p. - Published in : Appl. Surf. Sci. 542 (2021) 148552

2022-05-21
06:07
 Recent BDSIM Related Developments and Modeling of Accelerators / Nevay, Laurence J (JAI, UK) ; Abramov, Andrey (CERN) ; Alden, Siobhan E (JAI, UK) ; Boogert, Stewart T (JAI, UK) ; D'Alessandro, Gian Luigi (JAI, UK) ; Gibson, Stephen M (JAI, UK) ; Gnacadja, Eustache (Brussels U.) ; Hernalsteens, Cédric (CERN) ; Lefebvre, Helena (JAI, UK) ; Liu, Shan L (DESY) et al. Beam Delivery Simulation (BDSIM) is a program based on Geant4 that creates 3D radiation transport models of accelerators from a simple optical description in a vastly reduced time frame with great flexibility. It also uses ROOT and CLHEP to create a single simulation model that can accurately track all particle species in an accelerator to predict and understand beam losses, secondary radiation, dosimetric quantities and their origin. [...] Geneva : JACoW, 2021 - 4 p. - Published in : JACoW IPAC 2021 (2021) 4208-4211 Fulltext: PDF; In : 12th International Particle Accelerator Conference (IPAC 2021), Online, 24 - 28 May 2021, pp.4208-4211

2022-05-21
06:07
 Could "Flakes" of Neutral Paramagnetic or Dipolar Molecules Explain Beam Losses in the LHC? / Franchetti, Giuliano (Darmstadt, GSI ; Frankfurt U., FIAS) ; Zimmermann, Frank (CERN) "Flakes" of neutral water or oxygen molecules carrying an electric or magnetic dipole moment can be attracted and trapped by the electromagnetic field of the circulating LHC proton beam. The possible presence of such flakes in the vacuum system could explain beam losses and beam instabilities encountered during the 2017 and 2018 LHC runs, and the observed effect of an external magnetic field.. Geneva : JACoW, 2021 - 4 p. - Published in : JACoW IPAC 2021 (2021) 4254-4257 Fulltext: PDF; In : 12th International Particle Accelerator Conference (IPAC 2021), Online, 24 - 28 May 2021, pp.4254-4257

2022-05-16
17:11
 Applications of the Local Observable in Future Optics Measurements in HL-LHC and PETRA III / Wegscheider, Andreas (CERN) ; Tomás García, Rogelio (CERN) Phase advances among four nearby beam position monitors in a circular accelerator can be used to calculate a local observable of quadrupolar lattice imperfections. This work explores the applicability of this local observable to two different circular accelerators: PETRA III, a synchrotron light source, and the LHC, a hadron collider as well as its upgrade project HL-LHC. [...] Geneva : JACoW, 2021 - 4 p. - Published in : JACoW IPAC 2021 (2021) 3642-3645 Fulltext: PDF; In : 12th International Particle Accelerator Conference (IPAC 2021), Online, 24 - 28 May 2021, pp.3642-3645

2022-05-14
01:01
 Renovation of the Beam-Based Feedback Controller in the LHC / Grech, Leander (CERN) ; Alves, Diogo (CERN) ; Calia, Andrea (CERN) ; Hostettler, Michael (CERN) ; Jackson, Stephen (CERN) ; Valentino, Gianluca (U. Malta) ; Wenninger, Jorg (CERN) This work presents an extensive overview of the design choices and implementation of the Beam-Based Feedback System (BBFS) used in operation until the LHC Run 2. The main limitations of the BBFS are listed and a new design called BFCLHC, which uses the CERN Front-End Software Architecture (FESA), framework is proposed. [...] 2022 - 6 p. - Published in : JACoW ICALEPCS 2021 (2022) 671-676 Fulltext: PDF; In : 18th International Conference on Accelerator and Large Experimental Physics Control Systems, Online, 18 - 22 Oct 2021, pp.671-676

2022-05-14
01:01
 Denoising of Optics Measurements Using Autoencoder Neural Networks / Fol, Elena (CERN) ; Tomás García, Rogelio (CERN) Noise artefacts can appear in optics measurements data due to instrumentation imperfections or uncertainties in the applied analysis methods. A special type of semi-supervised neural networks, autoencoders, are widely applied to denoising tasks in image and signal processing as well as to generative modeling. [...] Geneva : JACoW, 2021 - 4 p. - Published in : JACoW IPAC 2021 (2021) 3915-3918 Fulltext: PDF; In : 12th International Particle Accelerator Conference (IPAC 2021), Online, 24 - 28 May 2021, pp.3915-3918