# Accelerator Physics

2017-08-08
22:18
 H$^{-}$ ion source for CERN's Linac4 accelerator: simulation, experimental validation and optimization of the hydrogen plasma / Mattei, Stefano Linac4 is the new negative hydrogen ion (H$^-$) linear accelerator of the European Organization for Nuclear Research (CERN) [...] CERN-THESIS-2017-109 - Lausanne : EPFL, 2017-07-25. - 139 p.

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2017-08-01
16:57
 PSB Chromaticity Correction in both Planes / Bartosik, Hannes (CERN) ; Schmidt, Frank (CERN) In view of the LHC injector upgrade program (LIU[1]), all LHC pre-accelerators and in particular the CERN Booster (PSB) are being reviewed for potential lattice optics and equipment optimizations. [...] CERN-ACC-NOTE-2017-0047. - 2017. - 6 p. Full text

2017-07-28
06:17
 Characterization of resonant impedances of CERN-SPS gate valves / Kaltenbacher, Thomas (CERN) ; Repond, Joel (CERN) ; Vollinger, Christine (CERN) For the CERN High Luminosity LHC project, a doubling of bunch intensity is foreseen. However, this intensity increase is currently limited by the LHC injector chain, in part due to longitudinal multi-bunch instabilities in the SPS. [...] 2017 - 7 p. - Published in : J. Phys. : Conf. Ser. 874 (2017) 012073

2017-07-28
06:17
 Multiparametric response of the HL-LHC Dynamic Aperture in presence of beam-beam effects / Pellegrini, D (CERN) ; Fartoukh, S (CERN) ; Karastathis, N (CERN) ; Papaphilippou, Y (CERN) We performed extended simulations of HL-LHC dynamic aperture in the presence of beam-beam effects in the weak-strong approximation, evaluating the contributions of parameters such as: bunch intensity, crossing angle, chromaticity, current in the Landau octupoles and multipole errors. From the beam dynamics point of view, the main difference between the LHC (until 2017) and the HL-LHC is the deployment of the achromatic telescopic squeezing (ATS) optics, allowing not only for a smaller β* reach, but also modifying the phase advances between the lattice correctors (sextupoles, octupoles) and the main IPs, and increasing the peak β functions in the arcs. [...] 2017 - 5 p. - Published in : J. Phys. : Conf. Ser. 874 (2017) 012007

2017-07-27
06:48
 Conceptual design of a pre-booster ring for $FCC e^+ e^-$ injector / Etisken, O (Ankara U.) ; Papaphilippou, Y (CERN) ; Ciftci, A K (Izmir U. Economics, Izmir) The $FCC e^+ e^-$ injector complex needs to produce and to transport a high-intensity $e^+/e^-$ beam at a fast repetition rate of about 0.1 Hz for topping up the collider at its collision energy. A basic parameter set exists for all the collider energies, assuming a 10 GeV linac operating with a large number of bunches being accumulated in the existing SPS, which serves as pre-accelerator and damping ring before the bunches are transferred to the high-energy booster. [...] 2017 - 7 p. - Published in : J. Phys. : Conf. Ser. 874 (2017) 012014

2017-07-27
06:48
 Experimental validation of the Achromatic Telescopic Squeezing (ATS) scheme at the LHC / Fartoukh, S (CERN) ; Bruce, R (CERN) ; Carlier, F (CERN) ; De Portugal, J Coello (CERN) ; Garcia-Tabares, A (CERN) ; Maclean, E (CERN) ; Malina, L (CERN) ; Mereghetti, A (CERN) ; Mirarchi, D (CERN) ; Persson, T (CERN) et al. The Achromatic Telescopic Squeezing scheme offers new techniques to deliver unprecedentedly small beam spot size at the interaction points of the ATLAS and CMS experiments of the LHC, while perfectly controlling the chromatic properties of the corresponding optics (linear and non-linear chromaticities, off-momentum beta-beating, spurious dispersion induced by the crossing bumps). The first series of beam tests with ATS optics were achieved during the LHC Run I (2011/2012) for a first validation of the basics of the scheme at small intensity. [...] 2017 - 7 p. - Published in : J. Phys. : Conf. Ser. 874 (2017) 012010

2017-07-27
06:48
 Multiparametric response of the LHC Dynamic Aperture in presence of beam-beam effects / Pellegrini, D (CERN) ; Antoniou, F (CERN) ; Fartoukh, S (CERN) ; Iadarola, G (CERN) ; Papaphilippou, Y (CERN) We performed extended simulations of LHC dynamic aperture (DA) in the presence of beam-beam effects in the weak-strong approximation, evaluating the contributions of parameters such as: tunes, optics, bunch intensity, crossing angle, emittance, chromaticity and current in the Landau octupoles. Here we present a summary of these studies, giving an overview of the amplitude of the LHC operational space and pointing out the remaining margins for mitigation of instabilities. [...] 2017 - 6 p. - Published in : J. Phys. : Conf. Ser. 874 (2017) 012006

2017-07-27
06:47
 Quench Level of the HL-LHC $Nb_3Sn$ IR Quadrupoles / Breschi, Marco (Bologna U.) ; Felcini, Enrico (Bologna U.) ; Bottura, Luca (CERN) The scope of the Large Hadron Collider Hi-Lumi Project at CERN includes the installation of several superconducting magnets wound with $Nb_3Sn$ Rutherford cables. The quench level of these magnets (i.e. [...] 2016 - 5 p. - Published in : IEEE Trans. Appl. Supercond. 27 (2017) 4002105 In : Applied Superconductivity Conference, Denver, CO, USA, 4 - 9 Sep 2016, pp.4002105

2017-07-26
06:24
 Optical diffraction radiation for position monitoring of charged particle beams / Kieffer, R (CERN) ; Bravin, E (CERN) ; Lefevre, T (CERN) ; Mazzoni, S (CERN) ; Bergamaschi, M (Royal Holloway, U. of London) ; Karataev, P (Royal Holloway, U. of London) ; Kruchinin, K (Royal Holloway, U. of London) ; Billing, M (Cornell U., CLASSE) ; Conway, J (Cornell U., CLASSE) ; Shanks, J (Cornell U., CLASSE) et al. In the framework of the future linear collider collaboration (CLIC, ILC), non-intercepting beam monitoring instruments are under development for very low emittance and high charge density beams. Optical diffraction radiation (ODR) was studied and developed during the last years focussing on beam size measurements. [...] 2017 - 4 p. - Published in : Nucl. Instrum. Methods Phys. Res., B 402 (2017) 88-91 Fulltext: PDF;

2017-07-22
13:26
 Computation of Optics Distortions due to Beam-Beam Interactions in the FCC-hh / Goncalves Jorge, Patrik CERN-THESIS-2016-317 -

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