# CERN Published Articles

2014-08-19
07:40
 Gravity and axions from a random UV QFT / Kiritsis, Elias It is postulated that the UV QFT is enormous and random. The coupling of the Standard Model to such QFT is analyzed. [...] arXiv:1408.3541; CCTP-2014-14; CERN-PH-TH-2014-153.- 2014 - 39 p. - Published in : EPJ Web Conf. 71 (2014) 00068 Fulltext: PDF; External link: Preprint

2014-08-12
15:37
 Recent Developments at the High-Charge PHIN Photoinjector and the CERN Photoemission Laboratory / Hessler, C ; Chevallay, E ; Doebert, S ; Fedosseev, V ; Martini, I ; Martyanov, M ; Perillo Marcone, A ; Sroka, S The high-charge PHIN photoinjector has originally been developed to study the feasibility of a photoinjector option for the drive beam of the CLIC Test Facility 3 (CTF3) at CERN and is now being used to inevestigate the feasibility of a drive beam photoinjector for CLIC. In this paper recent R&D; efforts to improve the parameters of the existing system towards CLIC requirements will be discussed. [...] CERN-ACC-2014-0193.- Geneva : CERN, 2014 - 4 p. Fulltext: PDF; In : 5th International Particle Accelerator Conference , Dresden, Germany, 15 - 20 Jun 2014, pp.4

2014-08-12
15:21
 FEM Analysis of Beam-Coupling Impedance and RF Contacts Criticality of the LHC UA9 Piezo Goniometer / Danisi, A ; Zannini, C ; Passarelli, A ; Masi, A ; Losito, R ; Salvant, B The UA9 piezo-goniometer has been designed to guarantee micro-radians-accuracy angular positioning of a silicon crystal for a crystal collimation experiment in the LHC, and to minimize the impact on the LHC beam coupling impedance. This paper presents a Finite Element Method (FEM) study of the device, in both parking and operational positions, to evaluate its impact on the LHC impedance budget. [...] CERN-ACC-2014-0192.- Geneva : CERN, 2014 - 4 p. Fulltext: PDF; In : 5th International Particle Accelerator Conference , Dresden, Germany, 15 - 20 Jun 2014, pp.4

2014-08-12
15:13
 Theoretical Analysis of Metamaterial Insertions for Resistive-Wall Beam-Coupling Impedance Reduction / Danisi, A ; Zannini, C ; Masi, A ; Losito, R ; Salvant, B Resistive-wall impedance usually constitutes a significant percentage of the total beam-coupling impedance budget of an accelerator. Reduction techniques often entail high electrical-conductivity coatings. [...] CERN-ACC-2014-0191.- Geneva : CERN, 2014 - 4 p. Fulltext: PDF; In : 5th International Particle Accelerator Conference , Dresden, Germany, 15 - 20 Jun 2014, pp.4

2014-08-12
15:03
 FLUKA Simulation of Particle Fluences to ALICE due to LHC Injection Kicker Failures / Shetty, N V ; Bracco, C ; Di Mauro, A ; Lechner, A ; Leogrande, E ; Uythoven, J The counter-rotating beams of the LHC are injected in insertion regions which also accommodate the ALICE and LHCb experiments. An assembly of beam absorbers ensures the protection of machine elements in case of injection kicker failures, which can affect either the injected or the stored beam. [...] CERN-ACC-2014-0190.- Geneva : CERN, 2014 - 4 p. Fulltext: PDF; In : 5th International Particle Accelerator Conference , Dresden, Germany, 15 - 20 Jun 2014, pp.4

2014-08-12
14:44
 Energy Deposition and Quench Level Calculations for Millisecond and Steady-State Quench Tests of LHC Arc Quadrupoles at 4 TeV / Shetty, N V ; Auchmann, B ; Chetvertkova, V ; Lechner, A ; Priebe, A ; Sapinski, M ; Verweij, A ; Wollmann, D In 2013, beam-induced quench tests with 4 TeV protons were performed to probe the quench level of LHC arc quadrupole magnets at timescales corresponding to millisecond beam losses and steady-state losses. As the energy deposition in magnet coils cannot be measured directly, this study presents corresponding FLUKA simulations as well as estimates of quench levels derived with the QP3 code. [...] CERN-ACC-2014-0189.- Geneva : CERN, 2014 - 5 p. Fulltext: PDF; In : 5th International Particle Accelerator Conference , Dresden, Germany, 15 - 20 Jun 2014, pp.5

2014-08-12
12:02
 Experiments of Laser Pointing Stability in Air and in Vacuum to Validate Micrometric Positioning Sensor / Stern, G ; Mainaud-Durand, H ; Piedigrossi, D ; Sandomierski, J ; Sosin, M ; Geiger, A ; Guillaume, S Aligning accelerator components over 200m with 10 μm accuracy is a challenging task within the Compact Linear Collider (CLIC) study. A solution based on laser beam in vacuum as straight line reference is proposed. [...] CERN-ACC-2014-0188.- Geneva : CERN, 2014 - 4 p. Fulltext: PDF; In : 5th International Particle Accelerator Conference , Dresden, Germany, 15 - 20 Jun 2014, pp.4

2014-08-07
16:40
 Mechanical Engineering and Design of Novel Collimators for HL-LHC / Carra, F ; Bertarelli, A ; Dallocchio, A ; Gentini, L ; Gradassi, P ; Maitrejean, G ; Manousos, A ; Mariani, N ; Mounet, N ; Quaranta, E et al. In view of High Luminosity LHC (HL-LHC) upgrades, collimator materials may become a limit to the machine performance: the high RF impedance of Carbon-Carbon composites used for primary and secondary collimators can lead to beam instabilities, while the Tungsten alloy adopted in tertiary collimators exhibits low robustness in case of beam-induced accidents. An R&D; program has been pursued to develop new materials overcoming such limitations. [...] CERN-ACC-2014-0184.- Geneva : CERN, 2014 - 5 p. Fulltext: PDF; In : 5th International Particle Accelerator Conference , Dresden, Germany, 15 - 20 Jun 2014, pp.5

2014-08-07
16:16
 High Power Molten Targets for Radioactive Ion Beam Production: from Particle Physics to Medical Applications / De Melo Mendonca, T M Megawatt-class molten targets, combining high material densities and good heat transfer properties are being considered for neutron spallation sources, neutrino physics facilities and radioactive ion beam production. For this last category of facilities, in order to cope with the limitation of long diffusion times affecting the extraction of short-lived isotopes, a lead-bismuth eutectic (LBE) target loop equipped with a diffusion chamber has been proposed and tested offline during the EURISOL design study. [...] CERN-ACC-2014-0183.- Geneva : CERN, 2014 - 4 p. Fulltext: PDF; In : 5th International Particle Accelerator Conference , Dresden, Germany, 15 - 20 Jun 2014, pp.4

2014-08-07
15:31
 The AWAKE Experimental Facility at CERN / Gschwendtner, E ; Bohl, T ; Bracco, C ; Butterworth, A ; Cipiccia, S ; Doebert, S ; Fedosseev, V ; Feldbaumer, E ; Hessler, C ; Hofle, W et al. AWAKE, an Advanced Wakefield Experiment is launched at CERN to verify the proton driven plasma wakefield acceleration concept. Proton bunches at 400 GeV/c will be extracted from the CERN SPS and sent along a 750 m long proton line to a plasma cell, a Rubidium vapour source, where the proton beam drives wakefields reaching accelerating gradients of several gigavolts per meter. [...] CERN-ACC-2014-0182.- Geneva : CERN, 2014 - 5 p. Fulltext: PDF; In : 5th International Particle Accelerator Conference , Dresden, Germany, 15 - 20 Jun 2014, pp.5