# SPS and CNGS

2019-10-22
17:27
 Possible Mitigations of Longitudinal Intensity Limitations for HL-LHC Beam in the CERN SPS / Repond, Joel The Super Proton Synchrotron (SPS) at CERN is the injector of the Large Hadron Collider (LHC), the world's largest particle collider. The High-Luminosity LHC (HL-LHC) project is a major step forward in the improvement of the LHC performances and it requires a doubling of the nominal bunch intensity of the current LHC beam. [...] CERN-THESIS-2019-173.- Lausanne : École polytechnique fédérale de Lausanne, 2019-10-11 - 198 p. Fulltext: PDF; External link: Approve this document (restricted)

2019-10-22
10:48
 MD 3292: Measurements of Landau Damping by Means of BTF Measurements / Tambasco, Claudia (EPFL - Ecole Polytechnique Federale Lausanne (CH)) ; Amorim, David (Universite Grenoble-Alpes (FR)) ; Buffat, Xavier (CERN) ; Bruce, Roderik (CERN) ; Gasior, Marek (CERN) ; Levens, Tom (CERN) ; Mereghetti, Alessio (CERN) ; Metral, Elias (CERN) ; Mounet, Nicolas (CERN) ; Pieloni, Tatiana (EPFL - Ecole Polytechnique Federale Lausanne (CH)) et al. The methodology applied in previous MDs has shown the possibility of using BTFs measurements to estimate the transverse Landau Damping of the beams for different machine conﬁgurations. [...] CERN-ACC-NOTE-2019-0045. - 2019. - 10 p. Full text

2019-10-22
10:41
 MD 3290: Instability threshold measurements in the presence of a controlled external excitation / Tambasco, Claudia (EPFL - Ecole Polytechnique Federale Lausanne (CH)) ; Barranco, Javier (EPFL - Ecole Polytechnique Federale Lausanne (CH)) ; Buffat, Xavier (CERN) ; Metral, Elias (CERN) ; Mounet, Nicolas (CERN) ; Levens, Tom (CERN) ; Pieloni, Tatiana (EPFL - Ecole Polytechnique Federale Lausanne (CH)) During the MD 2722 an unexpected instability was observed at ﬂat top energy during BTF measurements. [...] CERN-ACC-NOTE-2019-0044. - 2019. - 6 p. Full text

2019-10-22
06:18
 Numerical and experimental evaluation of the DQW crab cavity cryomodule thermal budget / Cano-Pleite, Eduardo (CERN) ; Brodzinski, Krzysztof (CERN) ; Capatina, Ofelia (CERN) ; Carra, Federico (CERN) One of the key devices of the HL-LHC project are SRF Crab Cavities. A cryomodule with two Double Quarter Wave (DQW) crab cavities has been fabricated at CERN in 2017 and successfully tested with beam in the Super Proton Synchrotron (SPS) in 2018. [...] 2019 - 4 p. - Published in : 10.18429/JACoW-IPAC2019-MOPTS092 Preprint: PDF; In : 10th International Particle Accelerator Conference, Melbourne, Australia, 19 - 24 May 2019, pp.MOPTS092

2019-10-22
06:18
 Mechanical robustness of HL-LHC collimator designs / Carra, Federico (CERN) ; Bertarelli, Alessandro (CERN) ; Gobbi, Giorgia (CERN) ; Guardia-Valenzuela, Jorge (CERN ; U. Zaragoza (main)) ; Guinchard, Michael (CERN) ; Harden, Fiona (CERN) ; Pasquali, Michele (CERN) ; Redaelli, Stefano (CERN) ; Skordis, Eleftherios (CERN) Two new absorbing materials were developed as collimator inserts to fulfil the requirements of HL-LHC higher brightness beams: molybdenum-carbide graphite (MoGr) and copper-diamond (CuCD). These materials were tested under intense beam impacts at CERN HiRadMat facility in 2015, when full jaw prototypes were irradiated. [...] 2019 - 4 p. - Published in : 10.18429/JACoW-IPAC2019-MOPTS091 Preprint: PDF; In : 10th International Particle Accelerator Conference, Melbourne, Australia, 19 - 24 May 2019, pp.MOPTS091

2019-10-22
06:18
 Beam-based measurement of the skew-sextupolar component of the radio frequency field of a HL-LHC-type crab-cavity / Carlà, Michele (CERN) ; Alekou, Androula (CERN ; U. Manchester (main)) ; Bartosik, Hannes (CERN) ; Carver, Lee (CERN ; U. Liverpool (main)) Two High Luminosity Large Hadron Collider (LHC) type crab-cavities have been installed in the CERN SPS for testing purposes. An attempt to characterize the skew-sextupolar component of the radio frequency field of the crab-cavity ($a_3$) has been carried out by means of beam-based techniques using turn-by-turn monitoring of the betatron motion. [...] 2019 - 4 p. - Published in : 10.18429/JACoW-IPAC2019-MOPTS090 Fulltext from publisher: PDF; In : 10th International Particle Accelerator Conference, Melbourne, Australia, 19 - 24 May 2019, pp.MOPTS090

2019-10-22
06:18
 Transverse beam dynamics studies with high intensity LHC beams in the SPS / Carlà, Michele (CERN) ; Bartosik, Hannes (CERN) ; Beck, Mario (CERN) ; Carver, Lee (CERN ; U. Liverpool (main)) ; Kain, Verena (CERN) ; Kotzian, Gerd (CERN) ; Li, Kevin (CERN) ; Rumolo, Giovanni (CERN) ; Zannini, Carlo (CERN) In order to reach the target beam parameters of the LHC injectors upgrade (LIU), about twice the presently operational intensity of LHC type beams has to be achieved. Although the planned upgrade of the main RF system will occur during the long shutdown, a series of measurements have been performed to assess the beam dynamics challenges with these very high intensity beams on the long SPS injection plateau. [...] 2019 - 4 p. - Published in : 10.18429/JACoW-IPAC2019-MOPTS089 Fulltext from publisher: PDF; In : 10th International Particle Accelerator Conference, Melbourne, Australia, 19 - 24 May 2019, pp.MOPTS089

2019-10-22
06:18
 Transverse emittance studies at extraction of the CERN PS Booster / Antoniou, Fanouria (CERN) ; Albright, Simon (CERN) ; Asvesta, Foteini (CERN) ; Bartosik, Hannes (CERN) ; Di Giovanni, Gian Piero (CERN) ; Forte, Vincenzo (CERN) ; Fraser, Matthew (CERN) ; Valdivieso, Ana (CERN) ; Huschauer, Alexander (CERN) ; Mikulec, Bettina (CERN) et al. Transverse emittance discrepancy in the beam transfer between the Proton Synchrotron Booster (PSB) and the Proton Synchrotron (PS) is observed in operational conditions for the LHC beams at CERN. The ongoing LHC Injectors Upgrade (LIU) project requires a tight budget for beam degradation along the injector chain and therefore the reason for this emittance discrepancy needs to be understood. [...] 2019 - 4 p. - Published in : 10.18429/JACoW-IPAC2019-MOPTS087 Fulltext from publisher: PDF; In : 10th International Particle Accelerator Conference, Melbourne, Australia, 19 - 24 May 2019, pp.MOPTS087

2019-10-22
06:18
 A two-mode model to study the effect of space charge on TMCI in the "long-bunch" regime / Métral, Elias (CERN) Using a two-mode approach for the Transverse Mode-Coupling Instability (TMCI) in the “short-bunch” regime (where the mode-coupling takes place between the modes 0 and – 1, such as in the CERN LHC), both a reactive damper (ReaD) and Space Charge (SC) are expected to be beneficial: the ReaD would shift the mode 0 up while SC would shift the mode – 1 down, but in both cases the coupling (and related instability) would occur at higher intensities. However, the situation is more involved in the “long-bunch” regime (where the mode-coupling takes place between higher-order modes, such as in the CERN SPS). [...] 2019 - 4 p. - Published in : 10.18429/JACoW-IPAC2019-MOPGW088 Fulltext from publisher: PDF; In : 10th International Particle Accelerator Conference, Melbourne, Australia, 19 - 24 May 2019, pp.MOPGW088

2019-10-22
06:18
 Verification by RF measurements of new HOM mitigation scheme developed for future SPS 33-cell accelerating structures / Kramer, Patrick (CERN ; RWTH Aachen U.) ; Farricker, Aaron (CERN) ; Vollinger, Christine (CERN) Longitudinal higher-order modes (HOMs) at a frequency of around 630 MHz in the 200 MHz travelling wave RF structures currently limit the beam intensities in the CERN SPS to less than that required by the High Luminosity (HL-) LHC. In the framework of the LHC Injectors Upgrade (LIU) project, the performance of the already existing HOM damping scheme for these standing wave modes must be improved. [...] 2019 - 3 p. - Published in : 10.18429/JACoW-IPAC2019-MOPGW076 Fulltext from publisher: PDF; In : 10th International Particle Accelerator Conference, Melbourne, Australia, 19 - 24 May 2019, pp.MOPGW076