Status and Plans for the Upgrade of the CERN PS Booster K. Hanke, LIU-PSB WP Holders CERN’s Proton Synchrotron Booster (PSB) is undergoing a massive upgrade program in the frame of the LHC Injectors Upgrade (LIU) project. During the first long LHC shutdown (LS1) some parts of the upgrade have already been implemented, and the machine has been successfully re-commissioned. More work is planned for the upcoming technical stops, notably in 2016/17, while most of the upgrade is planned to take place during the second long LHC shutdown (LS2). We report on the upgrade items already completed and commissioned, the first Run 2 beam performance and give a status of the ongoing design and integration work. Beam tests using a wide band RF system prototype in the CERN PS Booster M.M. Paoluzzi, M.E. Angoletta, A.J. Findlay, M. Haase, M. Jaussi, A. Jones, J.Molendijk Abstract: In the framework of the LHC Injectors Upgrade project (LIU) and in view of a complete replacement of the existing CERN PS Booster (PSB) RF systems, a small scale, wide band prototype cavity was installed in 2012 in the machine. Following the encouraging tests done using that limited device, an almost full scale, RF system prototype has been built and installed in the PSB during the Long Shutdown 1 (LS1). This modular, Finemet® loaded system covers the band 0.5 ÷ 4 MHz corresponding to the h=1 and h=2 frequency ranges. It uses solidstate power stages and includes fast RF feedback for beam loading compensation. New dedicated digital low level electronics implement all loops required for beam acceleration and interfaces with the general PSB control system. It allows using the new equipment at fundamental or second harmonic of the beam revolution frequency as well as operating it in parallel with the existing RF systems. This paper describes the low level and power sections of the project and reports about the achieved results and experience built up so far. Emittance measurements for future LHC beams using the PS Booster measurement line J.L. Abelleira, W. Bartmann, G.P. Di Giovanni, K. Hanke, B. Mikulec. The CERN PS Booster measurement line contains three pairs of SEM grids separated by drift space that measure the beam size in both planes. The combined analysis of these grids allows calculating a value for the transverse beam emittances. The precision of such a measurement depends on the ratio of rms beam size and wire spacing. Within the LIU-PSB upgrade the extraction energy of the PSB will be increased from currently 1.4 GeV to 2 GeV. This will result in smaller transverse beam sizes for certain future beams. In this paper comparative measurements will be presented between wire scanner measurements performed in the PSB rings before extraction and the SEM grid measurements. Systematic errors will be evaluated, and it will be analysed if the present layout of the transverse emittance measurement line will satisfy future requirements. Transverse impedance model of the CERN-PSB C. Zannini, B. Jones, K. Li, G. Rumolo In the framework of the PS-Booster upgrade project an accurate impedance model is needed in order to determine the effect on the beam stability and assess the impact of the new devices before installation in the machine. This paper describes the PSB impedance model which includes resistive wall, indirect space charge, flanges, step transitions, ejection kicker including cables, injection kickers and cavities. Each impedance contribution has been computed for different energies in the PSB cycle. Measurements of the coherent tune shifts have been performed and compared to calculations based on the impedance model. Longitudinal Injection Schemes For the CERN PS Booster at 160 MeV Including Space Charge Effects V. Forte (CERN and Universite’ Blaise Pascal, Clermont-Ferrand, France), E. Benedetto, A. Lombardi (CERN) In the framework of the LHC Injectors Upgrade (LIU) project, the CERN PS Booster will be upgraded to the injection energy of 160 MeV after the connection with Linac4. A multi-turn H- charge exchange injection is foreseen to tailor the initial beam profiles, both in the transverse and in the longitudinal plane. We are here reviewing in details the different longitudinal schemes, from the beam dynamics point of view, taking into account the needs of the large variety of the PS Booster users, spanning in intensity from 5e9 to about 1.6e13 protons per bunch. The baseline of the longitudinal injection has always been the longitudinal stacking with central energy modulation: this scheme has the advantage of filling uniformly the RF bucket, and mitigate transverse space charge, but it requires at least 40 turns of injection. A simpler injection protocol (without energy modulation) is here also analysed more in detail to find the optimum initial conditions in terms of bucket filling and reduction of transverse and longitudinal space charge effects, with the advantage of minimizing the number of turns for the low intensity beams (i.e. for the LHC). Simulations with space charge of the longitudinal capture process from different Linac4 trains are presented in this paper to fix different possible longitudinal injection scenarios during the future commissioning and operation with Linac4. Chromaticity Effects for Space Charge Dominated Beams in the CERN PS Booster V. Forte (CERN and Universite’ Blaise Pascal, Clermont-Ferrand, France), E. Benedetto, F. Schmidt (CERN) In the prospect of the LHC Injectors Upgrade (LIU) project, an extensive campaign is on-going in the CERN PS Booster to study collective effects for the future operation with the 160 MeV injection from the Linac4. In operation, the machine is running with natural chromaticity. This paper focuses on the study of the effects of chromaticity on losses and beam blow-up. Measurement of Resonance Driving Terms in the CERN PS Booster Using AC Dipole M. McAteer, J. Belleman, C. Carli, M. Gasior, B. Mikulec, R. Tomas In order to ensure that the CERN PS Booster will be able to deliver the higher-intensity beams required for high-luminosity LHC operation while adhering to strict limits on beam loss and emittance growth, both linear and nonlinear optics will have to be well-understood and controlled. For this purpose, a campaign has been undertaken to characterize resonance driving terms from analysis of turn-by-turn trajectories with driven coherent transverse oscillations. This paper presents the results of these measurements. Orbit Correction in the CERN PS Booster M. McAteer, E. Benedetto, C. Carli, G.P. Di Giovanni, B. Mikulec, R. Tomas Prior to the Long Shutdown of 2013-2014, control of the closed orbit in the four rings of the CERN PS Booster was achieved by adjusting the alignment of several focusing quadrupoles. Orbit corrector magnets are now available, which made it possible to remove the intentional quadrupole magnet misalignments and control the closed orbit using only the corrector dipoles. This paper summarizes the results of measurements and simulations of closed orbit correction in the PSB. CERN PS Booster Upgrade and LHC beams emittance E. Benedetto, Chiara Bracco; Jose Abelleira; Bettina Mikulec; Giovanni Rumolo; Vincenzo Forte By increasing the CERN PS Booster injection energy from 50 MeV to 160 MeV, the LHC Injector Upgrade Project aims at producing twice as brighter beams for the LHC. Previous measurements showed a linear dependence of the transverse emittance with the beam intensity and space-charge simulations confirmed the linear scaling. This paper is discussing in details the curve dependence on the longitudinal emittance and on the choice of the working point, with a special attention to the Hinjection process and to the beam dynamics in the first 5ms, during the fall of the injection chicane bump. New shaving scheme for low-intensity beams in the CERN PS Booster and feasibility at 160 MeV M. Kowalska (CERN, Geneva, Switzerland, EPFL, Lausanne, Switzerland), E. Benedetto, B. Mikulec, G. Rumolo (CERN, Geneva, Switzerland) The PS Booster is the first synchrotron in the CERN proton accelerator chain, serving all downstream machines. As part of the LHC Injector Upgrade Project, the PSB injection energy will increase from 50 MeV to 160 MeV and a new H- charge-exchange injection scheme will be implemented. Beam losses are a concern due to the increased injection energy, and mitigation scenarios are under investigation. On the other hand it is desirable for low-intensity beams to have the possibility to precisely tailor sub-micron beam emittances through controlled scraping (transverse shaving process) towards a suitable aperture restriction. Challenges are the higher activation potential of the beam and the smaller transverse beam sizes around 160 MeV as compared to 63 MeV, at which the shaving is presently done. This paper describes the proposal of a new shaving scheme, more robust with respect to the steering errors and the choice of the working point, which localizes the scraping losses on the main PS Booster aperture restriction. The robustness of the new method, together with the results of simulations and measurements are discussed for the current (50 MeV) and future (160 MeV) situation.