Jan Borburgh

160 MeV H - injection into the CERN PSB

The H- beam from the proposed LINAC4 will be injected into the four existing rings of the PS Booster at 160 MeV. A substantial upgrade of the injection region is required, including the modification of the beam distribution system and the construction of a new H- injection system. This paper discusses beam dynamics and hardware requirements and presents the results of optimisation studies of the injection process for different beam characteristics and scenarios. The resulting conceptual design of the injection region is presented, together with the main hardware modifications and performance specifications.

Technical challenges for head-on collisions and extraction at the ILC

An interaction region with head-on collisions is considered as an alternative to the baseline ILC configuration. Progress in the final focus optics design includes engineered large bore superconducting final doublet magnets and their 3D magnetic integration in the detector solenoids. Progress on the beam separation optics is based on technical designs of electrostatic separator and special extraction quadrupoles. The spent beam extraction is realized by a staged collimation scheme relying on realistic collimators.

Machine development studies for PSB extraction at 160 MeV and PSB to PS beam transfer

This paper collects the machine development (MD) activities for the beam transfer studies in 2016 concerning the PSB extraction and the PSB-to-PS transfer. Many topics are covered: from the 160 MeV extraction from the PSB, useful for the future commissioning activities after the connection with Linac4, to new methodologies for measuring the magnetic waveforms of kickers and dispersion reduction schemes at PS injection, which are of great interest for the LHC Injectors Upgrade (LIU) [1] project.

Direct Drive and Eddy Current Septa Magnet Designs for CERN's PSB Extraction at 2 GeV

In the framework of the LIU project, new septa magnets have been designed between CERNs PS booster (PSB) extraction and PS injection. The upgraded devices are to deal with the increased beam energy from 1.4 to 2 GeV at extraction of the PSB. The direct drive recombination septa in the PSB transfer line to the PS and the eddy current PS injection septum together with a bumper at injection have been investigated using finite-element software. For the recombination magnets, an increase in magnet length is sufficient to obtain the required deflection; however, for the PS injection elements, a more novel solution is necessary to also achieve increased robustness to extend the expected lifetime of the pulsed device. The injection septum will share the same vacuum vessel with an injection bumper, and both magnets will be located adjacent to each other. The new PS injection magnet will be the first septum operated at CERN based on eddy current technology. The magnetic modeling of the devices, the comparison of the performance of the present 1.4-GeV devices with the predictions for the upgraded 2-GeV devices, and the solutions retained to achieve the field requirements are described in this paper.

Design and Development of Separation Septa for the CERN PS Booster Upgrade

The CERN PS Booster project foresees the injection of 160 MeV H- ions into the booster from Linac 4. For this substantial upgrade, a system of 5 pulsed magnets (BIDIS) and 3 vertical septa (BISMV) will distribute the Linac pulses into the four-vertically separated Booster injection lines before being injected into the rings. This paper describes the magnetic calculations and the design concept that will be used in the future upgrade of the BISMV. Subsequently the mechanical design of the septa and their integration into the existing transfer line will be discussed.

The CERN PS multi-turn extraction based on beam splittting in stable islands of transverse phase space

The PS Multi-Turn Extraction Study Group M. J. Barnes*, O. E. Berrig, A. Beuret, J. Borburgh, P. Bourquin, R. Brown, J.-P. Burnet, F. Caspers, J.-M. Cravero, T. Dobers, T. Fowler, S. Gilardoni, M. Giovannozzi (Study Group Leader), M. Hourican, W. Kalbreier, T. Kroyer, F. di Maio, M. Martini, V. Mertens, E. Métral, K.-D. Metzmacher, C. Rossi, J.-P. Royer, L. Sermeus, R. Steerenberg, G. Villiger, T. Zickler

Ions for LHC: Beam Physics and Engineering Challenges

The first phase of the heavy ion physics program at the LHC aims to provide lead-lead collisions at energies of 5.5 TeV per colliding nucleon pair and ion-ion luminosity of 1027cm-2s-1. The transformation of CERN’s ion injector complex (Linac3-LEIR-PS-SPS) presents a number of beam physics and engineering challenges, which are described in this paper. In the LHC itself, there are fundamental performance limitations due to various beam loss mechanisms. To study these without risk of damage there will be an initial period of operation with a reduced number of nominal intensity bunches. While reducing the work required to commission the LHC with ions in 2008, this will still enable early physics discoveries.

Design and Construction of the Leir Injection Septa

The Low Energy Ion Ring (LEIR) transforms long pulses from Linac 3 into high brilliance ion bunches for LHC by means of multi-turn injection, electron cooling and accumulation. The LEIR injection comprises a magnetic DC septum followed by an inclined electrostatic septum. The electrostatic septum has been newly designed and built. The magnetic septum is mainly recovered from the former LEAR machine, but required a new vacuum chamber. Dynamic vacua in the 10-12mbar range are required, which are hard to achieve due to the high desorption rate of ions lost on the surface. A new interlock and displacement control system has also been developed. The major technical challenges to meet the magnetic, electrical and vacuum requirements will be discussed.