Professor Adrian Oeftiger: Publications

Self-consistent long-term dynamics of space charge driven resonances in 2D and 3D

Physical Review Accelerators and Beams American Physical Society (APS) 24:2 (2021) 024201

Authors:

Ingo Hofmann, Adrian Oeftiger, Oliver Boine-Frankenheim

Beam quality and beam loss predictions with space charge for SIS100

Journal of Instrumentation IOP Publishing 15:07 (2020) p07020-p07020

Authors:

V Kornilov, A Oeftiger, O Boine-Frankenheim, V Chetvertkova, S Sorge, P Spiller

Proof-of-principle direct measurement of Landau damping strength at the Large Hadron Collider with an anti-damper

ArXiv 2003.04383 (2020)

Authors:

SA Antipov, D Amorim, N Biancacci, X Buffat, E Métral, N Mounet, A Oeftiger, D Valuch

Overview of the CERN PSB-to-PS transfer line optics matching studies in view of the LHC Injectors Upgrade project

HB2018 - Proceedings of the 61st ICFA Advanced Beam Dynamics Workshop on High-Intensity and High-Brightness Hadron Beams (2018) 272-277

Authors:

V Forte, S Albright, W Bartmann, GP Di Giovanni, MA Fraser, C Hessler, A Huschauer, A Oeftiger

Abstract:

At injection into the CERN Proton Synchrotron (PS) a significant horizontal emittance blow-up of the present high brightness beams for the LHC is observed. A partial contribution to this effect is suspected to be an important mismatch between the dispersion function in the transfer line from the PS Booster (PSB) and the ring itself. This mismatch will be unacceptable in view of the beam parameters requested by the LHC Injectors Upgrade (LIU) project with high longitudinal emittance and momentum spread. To deliver the requested beam parameters the PSB-to-PS transfer line will be upgraded and the optics in the line changed to improve he matching from all the four PSB rings. A re-matching campaign from the PSB ring 3 has been carried out to evaluate the impact of the present optics mismatch as a source of emittance growth both in simulations and measurements.

Requirements and results for quadrupole mode measurements

HB2018 - Proceedings of the 61st ICFA Advanced Beam Dynamics Workshop on High-Intensity and High-Brightness Hadron Beams (2018) 393-398

Abstract:

Direct space charge may be quantified, and hence the beam brightness observed, by measuring the quadrupolar beam modes in the CERN Proton Synchrotron (PS). The spectrum of the transverse beam size oscillations (i.e. the quadrupolar beam moment) contains valuable information: the betatron envelope modes and the coherent dispersive mode indicate optics mismatch, while their frequency shifts due to space charge allow a direct measurement thereof. To measure the quadrupolar beam moment we use the Base-Band Q-meter system of the PS which is based on a four electrode stripline pick-up. Past experiments with quadrupolar pick-ups often investigated coasting beams, where the coherent betatron and dispersion modes correspond to single peaks in the tune spectrum. In contrast, long bunched beams feature bands of betatron modes: the mode frequencies shift depending on the transverse space charge strength which varies with the local line charge density. By using the new transverse feedback (TFB) in the PS as a quadrupolar RF exciter, we measured the quadrupolar beam transfer function. The beam response reveals the distinct band structure of the envelope modes as well as the coherent dispersive mode.

91̽��