TY - CONF AU - Tarazona, D. AU - Berz, M. AU - Makino, K. AU - Stratakis, D. AU - Syphers, M.J. ED - Schaa, Volker RW ED - Makino, Kyoko ED - Snopok, Pavel ED - Berz, Martin TI - Realistic Modeling of the Muon g-2 Experiment Beamlines at Fermilab J2 - Proc. of ICAP2018, Key West, FL, USA, 20-24 October 2018 CY - Key West, FL, USA T2 - International Computational Accelerator Physics Conference T3 - 13 LA - english AB - The main goal of the Muon g-2 Experiment at Fermilab (E989) is to measure the muon anomalous magnetic moment (a, also dubbed as the "anomaly’’) to unprecedented precision. This new measurement will allow to test the completeness of the Standard Model (SM) and to validate other theoretical models beyond the SM. Simulations of the beamlines from the pion production target to the entrance of the g-2 Storage Ring using COSY INFINITY contribute to the understanding and characterization of the muon beam production in relation to the statistical and systematics uncertainties of the E989 measurement. The effect of nonlinearites from fringe fields and high-order contributions on the beam delivery system performance are considered, as well as interactions with the beamline elements apertures, particle decay channels, spin dynamics, and beamline misalignments. PB - JACoW Publishing CP - Geneva, Switzerland SP - 134 EP - 139 KW - simulation KW - target KW - storage-ring KW - experiment KW - proton DA - 2019/01 PY - 2019 SN - 978-3-95450-200-4 DO - DOI: 10.18429/JACoW-ICAP2018-MOPAF02 UR - http://jacow.org/icap2018/papers/mopaf02.pdf ER - TY - CONF AU - Lunin, A. AU - Khabiboulline, T.N. AU - Solyak, N. AU - Sukhanov, A.I. AU - Yakovlev, V.P. ED - Schaa, Volker RW ED - Makino, Kyoko ED - Snopok, Pavel ED - Berz, Martin TI - Statistical Analysis of the Eigenmode Spectrum in the SRF Cavities with Mechanical Imperfections J2 - Proc. of ICAP2018, Key West, FL, USA, 20-24 October 2018 CY - Key West, FL, USA T2 - International Computational Accelerator Physics Conference T3 - 13 LA - english AB - The superconducting radio frequency (SRF) technology is progressing rapidly over last decades toward high accelerating gradients and low surface resistance making feasible the particle accelerators operation with high beam currents and long duty factors. However, the coherent RF losses due to high order modes (HOMs) excitation becomes a limiting factor for these regimes. In spite of the operating mode, which is tuned separately, the parameters of HOMs vary from one cavity to another due to finite mechanical tolerances during cavities fabrication. It is vital to know in advance the spread of HOM parameters in order to predict unexpected cryogenic losses, overheating of beam line components and to keep stable beam dynamics. In this paper we present the method of generating the unique cavity geometry with imperfections while preserving operating mode frequency and field flatness. Based on the eigenmode spectrum calculation of series of randomly generated cavities we can accumulate the data for the evaluation the HOM statistics. Finally, we describe the procedure for the estimation of the probability of the resonant HOM losses in the SRF resonators. The study of these effects leads to specifications of SC cavity and cryomodule and can significantly impact on the efficiency and reliability of the machine operation PB - JACoW Publishing CP - Geneva, Switzerland SP - 265 EP - 269 KW - cavity KW - HOM KW - SRF KW - linac KW - cryomodule DA - 2019/01 PY - 2019 SN - 978-3-95450-200-4 DO - DOI: 10.18429/JACoW-ICAP2018-TUPAG04 UR - http://jacow.org/icap2018/papers/tupag04.pdf ER - TY - CONF AU - Webb, S.D. AU - Bruhwiler, D.L. AU - Burov, A.V. AU - Cook, N.M. AU - Lebedev, V.A. AU - Nagaitsev, S. ED - Schaa, Volker RW ED - Makino, Kyoko ED - Snopok, Pavel ED - Berz, Martin TI - Theoretical and Computational Modeling of a Plasma Wakefield BBU Instability J2 - Proc. of ICAP2018, Key West, FL, USA, 20-24 October 2018 CY - Key West, FL, USA T2 - International Computational Accelerator Physics Conference T3 - 13 LA - english AB - Plasma wakefield accelerators achieve accelerating gradients on the order of the wave-breaking limit, m c² k_{p}/e, so that higher accelerating gradients correspond to shorter plasma wavelengths. Small-scale accelerating structures, such as plasma and dielectric wakefields, are susceptible to the beam break-up instability (BBU), which can be understood from the Panofsky-Wenzel theorem: if the fundamental accelerating mode scales as b⁻¹ for a structure radius b, then the dipole mode must scale as b⁻³, meaning that high accelerating gradients necessarily come with strong dipole wake fields. Because of this relationship, any plasma-accelerator-based future collider will require detailed study of the trade-offs between extracting the maximum energy from the driver and mitigating the beam break-up instability. Recent theoretical work* predicts the tradeoff between the witness bunch stability and the amount of energy that can be extracted from the drive bunch, a so-called efficiency-instability relation . We will discuss the beam break-up instability and the efficiency-instability relation and the theoretical assumptions made in reaching this conclusion. We will also present preliminary particle-in-cell simulations of a beam-driven plasma wakefield accelerator used to test the domain of validity for the assumptions made in this model. PB - JACoW Publishing CP - Geneva, Switzerland SP - 341 EP - 344 KW - plasma KW - wakefield KW - impedance KW - dipole KW - simulation DA - 2019/01 PY - 2019 SN - 978-3-95450-200-4 DO - DOI: 10.18429/JACoW-ICAP2018-WEPLG03 UR - http://jacow.org/icap2018/papers/weplg03.pdf ER -