Home Supervised theses Invited talks Conference Pub. CERN notes
  1. R. Tomas Garcia, ``Farey Fractions with equal numerators and the rank of unit fractions'', Integers 24 #A63, 2024
  2. R. Tomas et al., ``Optics for Landau damping with minimized octupolar resonances in the LHC'', JINST 19 T05010, 2024
  3. N. Mounet, R. Tomas et al., ``High intensity beam dynamics assessment and challenges for HL-LHC'', JINST 19, T05016, 2024. DOI: 0.1088/1748-0221/19/05/T05016
  4. D. Di Croce et al., ``Optimizing dynamic aperture studies with active learning'', JINST, 19 P04004 DOI 10.1088/1748-0221/19/04/P04004 (2024).
  5. C. Garcia-Jaimes et al, ``Exploring Fcc-ee Optics Designs with Combined Function Magnets'', J. Phys.: Conf. Ser. 2687 022007 (2024) DOI 10.1088/1742-6596/2687/2/022007
  6. C. Garcia-Jaimes et al, ``Impact of Dipole Quadrupolar Errors in Fcc-ee'', J. Phys.: Conf. Ser. 2687 022006 (2024) DOI 10.1088/1742-6596/2687/2/022006
  7. M. Hofer and R. Tomas, ``Impact of two-dimensional decoherence on the measurement of resonance driving terms'', J. Phys.: Conf. Ser. 2687 062006 (2024)DOI 10.1088/1742-6596/2687/6/062006
  8. S. Yammine et al., ``Experimental Program of the HL-LHC Inner Triplet String Test at CERN'', IEEE Transactions on Applied Superconductivity, vol. 34, issue 5, 2024. DOI: 10.1109/TASC.2023.3349356
  9. A. Babaev, T. Barklow, O. Karacheban, W. Kozanecki, I. Kralik, A. Mehta, G. Pasztor, T. Pieloni, D. Stickland, C. Tambasco, R. Tomas and J. Wanczyk, ``Impact of beam-beam effects on absolute luminosity calibrations at the CERN Large Hadron ColliderImpact of beam-beam effects on absolute luminosity calibrations at the CERN Large Hadron Collider'', EPJ C, Vol. 84, 17, (2024).
  10. Joschua Dilly et al., ``First operational dodecapole correction in the LHC''
    Phys. Rev. Accel. Beams 26, 121001. Published 5 December 2023.
  11. Andrii Pastushenko, Rogelio Tomas, and Angeles Faus-Golfe, ``Optics design with longer L* for the final focus system of Compact Linear Collider 380 GeV''
    Phys. Rev. Accel. Beams 26, 091003. Published 26 September 2023.
  12. Felix Soubelet, Tobias Persson, Rogelio Tomas, Oznur Apsimon, and Carsten P. Welsch , ``Rigid waist shift: A new method for local coupling corrections in the LHC interaction regions''
    Phys. Rev. Accel. Beams 26, 051001 (May 2023).
  13. Tessa K Charles, Bernhard Holzer, Rogelio Tomas, Katsunobu Oide, Léon van Riesen-Haupt and Frank Zimmermann , ``Alignment & stability challenges for FCC-ee''
    EPJ Techniques and Instrumentation vol. 10, Article number: 8 (2023).
  14. A. Bazzani, F. Capoani, M. Giovannozzi, and R. Tomas , ``Nonlinear cooling of an annular beam distribution''
    Phys. Rev. Accel. Beams 26, 024001 (2023).
  15. R. Tomas et al, ``Operational scenario of first high luminosity LHC run''
    J. Phys.: Conf. Ser. 2420 012003 (2023).
  16. E. H. Maclean et al, ``Prospects for beam-based study of dodecapole nonlinearities in the CERN High-Luminosity Large Hadron Collider''
    Eur. Phys. J. Plus (2022) 137:1249.
  17. N. Fuster-Martinez et al, ``Aperture measurements with ac dipoles and movable collimators in the Large Hadron Collider''
    Phys. Rev. Accel. Beams 25, 101002, October 2022.
  18. H. Garcia Morales et al, ``Phase advance constraint in K modulation for precise beta-function determination''
    Phys. Rev. Accel. Beams 25, 041002, April 2022.
  19. J. Keintzel et al, ``Experimental beam tests for FCC-ee''
    PoS Vol. 398.
  20. R. Tomas, ``Partial Franel Sums''
    Journal of Integer Sequences, Vol. 25 (2022) Article 22.1.5.
  21. P. Arpaia et al, ``Beam Measurements and Machine Learning at the CERN Large Hadron Collider''
    IEEE Instrumentation & Measurement Magazine, Volume: 24, Issue: 9 (2021) .
  22. V. Cilento et al, ``Dual beam delivery system serving two interaction regions for the Compact Linear Collider''
    Phys. Rev. Accel. Beams 24, 071001 (2021) .
  23. R. Calaga et al, ``First demonstration of the use of crab cavities on hadron beams''
    Phys. Rev. Accel. Beams 24, 062001 (2021) .
  24. R. Yang, A. Pastushenko, V. Cilento, K. Kubo, T. Naito, T. Okugi, N. Terunuma, and R. Tomas ``Momentum bandwidth of the KEK Accelerator Test Facility 2''
    Phys. Rev. Accel. Beams 24, 051001 (2021) .
  25. E. Fol, R. Tomás and G. Franchetti, ``Supervised learning-based reconstruction of magnet errors in circular accelerators''
    The European Physical Journal Plus vol. 136, Article number: 365 (2021) .
  26. E. Fol, R. Tomás, J. Coello de Portugal, and G. Franchetti, ``Detection of faulty beam position monitors using unsupervised learning''
    Phys. Rev. Accel. Beams 23, 102805, 2020.
  27. J. Keintzel, R. Tomás, R. Bruce, M. Giovannozzi, T. Risselada, and F. Zimmermann, ``Lattice and optics options for possible energy upgrades of the Large Hadron Collider''
    Phys. Rev. Accel. Beams 23, 101602, 2020.
  28. M. Hofer and R. Tomas, ``Effect of local linear coupling on linear and nonlinear observables in circular accelerators''
    Phys. Rev. Accel. Beams 23, 094001, 2020.
  29. R. Tomas, ``Equalities between greatest common divisors involving three coprime pairs''
    Notes on Number Theory and Discrete Mathematics, Volume 26, 2020, Number 3, Pages 5-7. DOI: 10.7546/nntdm.2020.26.3.5-7
  30. P. Arpaia et al, ``Machine learning for beam dynamics studies at the CERN Large Hadron Collider''
    NIM A, V. 985, 2020.
  31. R. Yang et al, ``Tuning the ultralow beta* optics at the KEK Accelerator Test Facility 2''
    Phys. Rev. Accel. Beams 23, 071003, May 2020.
  32. J. Orgen et al, ``Tuning the Compact Linear Collider 380 GeV final-focus system using realistic beam-beam signals''
    Phys. Rev. Accel. Beams 23, 051002, May 2020.
  33. A. Wegscheider and R. Tomas, ``Local observable for linear lattice imperfections in circular accelerators''
    Phys. Rev. Accel. Beams 23, 054002, May 2020.
  34. A. Garcia-Tabares, et al, ``Optics-measurement-based beam position monitor calibrations in the LHC insertion regions''
    Phys. Rev. Accel. Beams 23, 042801, April 2020.
  35. J. Coello, R. Tomas, et al, ``New local optics measurements and correction techniques for the LHC and its luminosity upgrade''
    Phys. Rev. Accel. Beams 23, 041001, April 2020.
  36. R. Tomas, J. Keintzel and S. Papadopoulou ``Emittance growth from luminosity burn-off in future hadron colliders''
    Phys. Rev. Accel. Beams 23, 031002, March 2020.
  37. P. Thrane, R. Tomas et al, ``Measuring beta* in SuperKEKB with K modulation''
    Phys. Rev. Accel. Beams 23, 012803, January 2020.
  38. J. Coello, R. Tomas et al, ``Impact of flux jumps in future colliders''
    Phys. Rev. Accel. Beams 23, 011001, January 2020.
  39. A. Abada, et al, ``HE-LHC: The High-Energy Large Hadron Collider''
    The European Physical Journal Special Topics, vol 228, issue 5, pages 1109-1382 (2019).
  40. A. Abada, et al, ``FCC-hh: The Hadron Collider''
    The European Physical Journal Special Topics, 228, issue 4, 2019
  41. E.H. Maclean, et al., ``New approach to LHC optics commissioning for the nonlinear era''
    Phys. Rev. Accel. Beams 22, 061004, 2019
  42. A. Abada, et al, ``FCC-ee: The Lepton Collider''
    The European Physical Journal Special Topics, 228, issue 2, 2019
  43. A. Abada et al, ``FCC Physics Opportunities''
    The European Physical Journal C, 79, issue 6, 2019
  44. T.H.B. Persson, R. Tomas and, E.H. Maclean, ``Suppression of amplitude dependent closest tune approach and its behavior under forced oscillations''
    Phys. Rev. Accel. Beams 22, 051001 (2019)
  45. F.S. Carlier, R. Tomas, E.H. Maclean, and T.H.B. Persson, ``First experimental demonstration of forced dynamic aperture measurements with LHC ac dipoles''
    Phys. Rev. Accel. Beams 22, 031002 (2019)
  46. R. Tomas, M. Benedikt, M. Hofer, J. Keintzel and F. Zimmermann, ``Towards future colliders''
    PoS Vol. 321 LHCP2018
    DOI: https://doi.org/10.22323/1.321.0268
  47. J. Abelleira et al ``High-Energy LHC design''
    Journal of Physics: Conference Series 1067 (2), 022009
  48. E. Marin, A. Latina, D. Schulte, R. Tomas, J. Pfingstner, ``Tuning of clic-final focus system 3 tev baseline design under static and dynamic imperfections''
    Journal of Physics: Conference Series 1067 (2), 022014
  49. Luis Eduardo Medina Medrano, R. Tomas, Gianluigi Arduini, Mauro Napsuciale Mendívil, ``Assessment of the performance of High Luminosity LHC operational scenarios: integrated luminosity and effective pile-up density''
    Canadian Journal of Physics, Vol. 0 (2018)
    https://doi.org/10.1139/cjp-2018-0291
  50. D.R. Bett et al, ``Compensation of orbit distortion due to quadrupole motion using feed-forward control at KEK ATF''
    NIM-A (2018)
    https://doi.org/10.1016/j.nima.2018.03.037
  51. Aysegul Usun Simitcioglu, Ilhan Tapan, R. Tomas, J. Barranco, M. Beckmann, ``Beam offsets impact on the polarization in the CLIC Beam Delivery System''
    Canadian Journal of Physics Vol. 0, January (2018) https://doi.org/10.1139/cjp-2017-0251
  52. E. Marin, A. Latina, R. Tomas, and D. Schulte, ``Final focus system tuning studies towards Compact Linear Collider feasibility''
    Phys. Rev. Accel. Beams 21, 011003 (2018)
  53. Fabien Plassard, Andrea Latina, Eduardo Marin, Rogelio Tomás, and Philip Bambade, ``Quadrupole-free detector optics design for the Compact Linear Collider final focus system at 3 TeV''
    Phys. Rev. Accel. Beams 21, 011002 (2018)
  54. Javier Fernando Cardona, Alba Carolina Garcia Bonilla, and Rogelio Tomas Garcia, "Local correction of quadrupole errors at LHC interaction regions using action and phase jump analysis on turn-by-turn beam position data"
    Phys. Rev. Accel. Beams 20, 111004 (2017)
  55. A. Wegscheider, A. Langner, R. Tomas and A. Franchi, "Analytical N beam position monitor method"
    Phys. Rev. Accel. Beams 20, 111002 (2017)
  56. R. Tomas, X. Buffat, S. White, J. Barranco, P. Gonçalves Jorge, and T. Pieloni, "Beam-beam amplitude detuning with forced oscillations"
    Phys. Rev. Accel. Beams 20, 101002 (2017)
  57. Roman Martin, Maria Ilaria Besana, Francesco Cerutti, Andy Langner, Rogelio Tomas, Emilia Cruz-Alaniz, and Barbara Dalena, "Interaction region design driven by energy deposition"
    Phys. Rev. Accel. Beams 20, 081005 (2017)
  58. L. Malina, J. Coello de Portugal, T. Persson, P.K. Skowronski, R. Tomas, A. Franchi, and S. Liuzzo, "Improving the precision of linear optics measurements based on turn-by-turn beam position monitor data after a pulsed excitation in lepton storage rings"
    Phys. Rev. Accel. Beams 20, 082802 (2017)
  59. S. Fartoukh et al, "Experimental validation of the Achromatic Telescopic Squeezing (ATS) scheme at the LHC"
    IOP Conf. Series: Journal of Physics: Conf. Series 874 012010 (2017)
  60. T. Persson, F. Carlier, J. Coello de Portugal, A. Garcia-Tabares Valdivieso, A. Langner, E.H. Maclean, L. Malina, P. Skowronski, B. Salvant, R. Tomas, and A.C. Garcia Bonilla, "LHC optics commissioning: A journey towards 1% optics control",
    Phys. Rev. Accel. Beams, 20, 061002 (2017)
  61. Rogelio Tomas, Masamitsu Aiba, Andrea Franchi, and Ubaldo Iriso, "Review of linear optics measurement and correction for charged particle accelerators",
    Phys. Rev. Accel. Beams, 20, 054801 (2017)
  62. F. Carlier and R. Tomas, "Accuracy and feasibility of the beta* measurement for LHC and High Luminosity LHC using k-modulation",
    Phys. Rev. Accel. Beams, 20, 011005 (2017)
  63. G. Arduini et al, "High Luminosity LHC: challenges and plans",
    Journal of Instrumentation, Volume 11, (2016)
  64. J. Barranco Garcia, R. De Maria, A. Grudiev, R. Tomas Garcia, R. B. Appleby and D. R. Brett, "Long term dynamics of the high luminosity Large Hadron Collider with crab cavities",
    Phys. Rev. Accel. Beams 19, 101003 (2016)
  65. M. Patecki, D. Bett, E. Marin, F. Plassard, R. Tomas, K. Kubo, S. Kuroda, T. Naito, T. Okugi, T. Tauchi, and N. Terunuma, "Probing half beta*y optics in the Accelerator Test Facility 2",
    Phys. Rev. Accel. Beams 19, 101001 (2016)
  66. A. Langner, G. Benedetti, M. Carla, U. Iriso, Z. Marti, J. Coello de Portugal, and R. Tomas, "Utilizing the N beam position monitor method for turn-by-turn optics measurements",
    Phys. Rev. Accel. Beams 19, 092803 (2016)
  67. R. Tomas, T.H.B Persson and E.H. Maclean, "Amplitude dependent closest tune approach",
    Phys. Rev. Accel. Beams 19, 071003 (2016)
  68. E. Todesco et al, "The Magnetic Model of the LHC at 6.5 TeV",
    IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, VOL. 26, NO. 4, JUNE 2016(2016)
  69. D. Andreea Popescua and R. Tomas Garcia, "Multivariate Polynomial Multiplication on GPU",
    Procedia Computer Science Volume 80, 2016, Pages 154-165
  70. N. Biancacci and R. Tomas, "Using ac dipoles to localize sources of beam coupling impedance",
    Phys. Rev. Accel. Beams 19, 054001 (2016)
  71. O.R. Blanco, R. Tomas, and P. Bambade, "Beam focusing limitation from synchrotron radiation in two dimensions",
    Phys. Rev. Accel. Beams 19, 021002 (2016)
  72. S. Kuroda et al, "ATF2 for Final Focus Test Beam for Future Linear Colliders",
    Nuclear and Particle Physics Proceedings Volumes 273-275 (2016).
  73. E.H. Maclean, R. Tomas, M. Giovannozzi, and T.H.B. Persson "First measurement and correction of nonlinear errors in the experimental insertions of the CERN Large Hadron Collider"
    Phys. Rev. ST Accel. Beams 18, 121002 (2015)
  74. E. Cruz-Alaniz, D. Newton, R. Tomas and M. Korostelev, "Design of the large hadron electron collider interaction region"
    Phys. Rev. ST Accel. Beams 18, 111001 (2015)
  75. A. Langner and R. Tomas, "Optics measurement algorithms and error analysis for the proton energy frontier"
    Phys. Rev. ST Accel. Beams 18, 031002 2015
  76. R. Tomas et al, "FCC study: parameters and optics for hadron and lepton colliders"
    Nuclear and Particle Physics Proceedings 273-275. ICHEP 2014
  77. J. Pfingstner et al, "Mitigation of ground motion effects in linear accelerators via feed-forward control"
    Phys. Rev. ST Accel. Beams, 17, 122801 2014
  78. Hector Garcia Morales and Rogelio Tomas Garcia, "Final-focus systems for multi-TeV linear colliders"
    Phys. Rev. ST Accel. Beams, 17, 101001 2014
  79. Marcin Patecki and Rogelio Tomas, "Effects of quadrupole fringe fields in final focus systems for linear colliders"
    Phys. Rev. ST Accel. Beams, 17, 101002 2014
  80. D.R. Brett et al , "Accurate crab cavity modeling for the high luminosity Large Hadron Collider"
    Phys. Rev. ST Accel. Beams, 17, 104001, 2014
  81. E. H. Maclean, R. Tomas, F. Schmidt, and T.H.B. Persson, "Measurement of nonlinear observables in the Large Hadron Collider using kicked beams"
    Phys. Rev. ST Accel. Beams, 17, 081002, August 2014
  82. T. Persson and R. Tomas, "Improved control of the betatron coupling in the Large Hadron Collider"
    Phys. Rev. ST Accel. Beams, 17, 051004 2014
  83. Y. Inntjore Levinsen, B. Dalena, R. Tomas, and D. Schulte, "Impact of detector solenoid on the Compact Linear Collider luminosity performance"
    Phys. Rev. ST Accel. Beams, 17, 051002 2014
  84. Bruce Yee-Rendon et al, "Simulations of fast crab cavity failures in the high luminosity Large Hadron Collider"
    Phys. Rev. ST Accel. Beams, 17, 051001 2014
  85. T. Okugi et al, "Linear and second order optics corrections for the KEK Accelerator Test Facility final focus beam line"
    Phys. Rev. ST Accel. Beams 17, 023501 (2014)
  86. E. Marin, R. Tomas et al, "Design and high order optimization of the Accelerator Test Facility lattices"
    Phys. Rev. ST Accel. Beams 17, 021002 (2014)
  87. R. Tomas, "From Farey sequences to resonance diagrams"
    Phys. Rev. ST Accel. Beams 17, 014001 (2014)
  88. G.R. White et al, "Experimental validation of a novel compact focusing scheme for future energy-frontier linear lepton colliders"
    Phys. Rev. Lett. 112, 034802 (2014)
  89. A. Seryi, R. Tomas et al, "Experimental and theoretical progress of linear collider final focus design and ATF2 facility"
    NIM-A, Volume 740, (2014)
  90. X. Shen, S. Y. Lee, M. Bai, S. White, G. Robert-Demolaize, Y. Luo, A. Marusic and R. Tomas, "Application of independent component analysis to ac dipole based optics measurement and correction at the Relativistic Heavy Ion Collider",
    Phys. Rev. ST Accel. Beams 16, 111001, November 2013.
  91. T. Persson, Y. Levinsen, R. Tomas, E. Maclean, "Chromatic coupling correction in the Large Hadron Collider",
    Phys. Rev. ST Accel. Beams 16, 081003, September 2013.
  92. S. White, E. Maclean, R. Tomas, "Direct amplitude detuning measurement with AC dipole",
    Phys. Rev. ST Accel. Beams 16, 071002, July 2013.
  93. J. L. Abelleira Fernandez et al, "A Large Hadron Electron Collider at CERN Report on the Physics and Design Concepts for Machine and Detector",
    J. Phys. G: Nucl. Part. Phys. 39 075001
  94. Javier Barranco Garcia, E. Marin, and R. Tomas, "Luminosity studies in a traveling waist regime in the Compact Linear Collider",
    Phys. Rev. ST Accel. Beams 16, 041001, Published 4 April 2013
  95. R. Tomas, T. Bach, R. Calaga, A. Langner, Y. I. Levinsen, E. H. Maclean, T. H. B. Persson, P. K. Skowronski, M. Strzelczyk, G. Vanbavinckhove, and R. Miyamoto "Record low beta beating in the LHC",
    Phys. Rev. ST Accel. Beams 15, 091001, Published 28 September 2012
  96. B. Dalena, J. Barranco, A. Latina, E. Marin, J. Pfingstner, D. Schulte, J. Snuverink, R. Tomas, and G. Zamudio, ``Beam delivery system tuning and luminosity monitoring in the Compact Linear Collider'',
    Phys. Rev. ST Accel. Beams 15, 051006, Published 30 May 2012
  97. K. Ohmi, R. Tomas et al, ``Response of colliding beam-beam system to harmonic excitation due to crab-cavity rf phase modulation'',
    Phys. Rev. ST Accel. Beams 14, 111003 (2011).
  98. A. Franchi et al, ``Vertical emittance reduction and preservation in electron storage rings via resonance driving terms correction'',
    Phys. Rev. ST Accel. Beams 14, 034002 (2011).
  99. R. Tomas et al, ``LHC optics model, measurements and corrections'',
    Phys. Rev. ST Accel. Beams 13, 121004 (2010).
  100. P. Bambade et al. (ATF Collaboration), "Present status and first results of the final focus beam line at the KEK Accelerator Test Facility"
    Phys. Rev. ST Accel. Beams 13, 042801, Published 21 April 2010
  101. Yi-Peng Sun, Ralph Assmann, Rogelio Tomas, and Frank Zimmermann, "Crab dispersion and its impact on the CERN Large Hadron Collider collimation",
    Phys. Rev. ST Accel. Beams 13, 031001, Published 12 March 2010
  102. R. Tomas, Overview of the Compact Linear Collider" ,
    Phys. Rev. ST Accel. Beams 13, 014801, Published 11 January 2010
  103. Yi-Peng Sun, Ralph Assmann, Javier Barranco, Rogelio Tomas, Thomas Weiler, Frank Zimmermann, Rama Calaga, and Akio Morita, "Beam dynamics aspects of crab cavities in the CERN Large Hadron Collider"
    Phys. Rev. ST Accel. Beams 12, 101002, Published 14 October 2009
  104. M. Aiba, S. Fartoukh, A. Franchi, M. Giovannozzi, V. Kain, M. Lamont, R. Tomas, G. Vanbavinckhove, J. Wenninger, F. Zimmermann, R. Calaga, and A. Morita, ``First beta-beating measurement and optics analysis for the CERN Large Had ron Collider'',
    Phys. Rev. ST Accel. Beams 12, 081002 (2009).
  105. R. Tomas, M. Giovannozzi, and R. de Maria, ``Nonlinear correction scheme s for the phase 1 LHC insertion region upgrade and dynamic aperture studies'',
    Phys. Rev. ST Accel. Beams 12, 011002 (2009).
  106. A. Franchi, E. Metral and R. Tomas, ``Emittance sharing and exchange driven by linear betatron coupling in circular accelerators'',
    Phys. Rev. ST Accel. Beams 10, 064003 (2007).
  107. A. Franchi, R. Tomas, and F. Schmidt, "Magnet strength measurement in circular accelerators from beam position monitor data",
    Phys. Rev. ST Accel. Beams 10, 074001 (2007).
  108. M. Benedikt, A. Faus-Golfe, F. Schmidt, R. Tomas, P. Urschutz, "Driving Term Experiments at CERN",
    Phys. Rev. ST Accel. Beams 10, 034002 (2007).
  109. R. Tomas, ``Nonlinear optimization of beam lines'',
    Phys. Rev. ST Accel. Beams 9, 081001 (2006).
  110. R. Tomas, M. Bai, R. Calaga, W. Fischer, A. Franchi and G. Rumolo, ``Measurement of global and local resonance terms'',
    Phys. Rev. ST Accel. Beams 8, issue 2, 024001 (2005).
  111. R. Calaga, R. Tomas and A. Franchi, ``Betatron coupling: Merging the Ha miltonian and Matrix approaches'',
    Phys. Rev. ST Accel. Beams 8, 034001 (2005).
  112. R. Tomas, ``Adiabaticity of the ramping process of an ac dipole'',
    Phys. Rev. ST Accel. Beams 8, 024401 (2005).
  113. G. Rumolo and R. Tomas ``Decoherence of a longitudinally kicked beam with chromaticity'',
    NIM-A 528 (2004) 670-676.
  114. R. Calaga and R. Tomas ``Statistical analysis of RHIC beam position monitors performance'',
    Phys. Rev. ST Accel Beams, volume 7, 042801 (2004).
  115. R. Tomas "Normal Form of Particle Motion under the Influence of an AC Dipole",
    Phys. Rev. ST Accel Beams, volume 5 54001 (2002).