PICs in the injector complex - what are we talking about?

This presentation will identify PIC activities for the LHC injector chain, and point out borderline cases to pure consolidation and upgrade. The most important PIC items will be listed for each LIU project (PSB, PS, SPS) and categorized by a) the risk if not performed and b) the implications of doing them. This will in particular address the consequences on performance, schedule, reliability, commissioning time, operational complexity etc. The additional cost of PICs with regard to pure consolidation will be estimated and possible time lines for the implementation of the PICs will be discussed. In this context, it will be evaluated if the PICs can be implemented over several machine stops. ASSUMPTIONS We do not treat in this paper Linac4 and the modifications in the PSB required for the connection of Linac4. Ions will not be treated in this paper either; we refer to the session dedicated on ions. DEFINITION OF PICS In this section we will attempt a definition of Performance Improving Consolidation (PIC) items in comparison with pure Consolidation and Upgrade. Consolidation refers to partial or complete replacement of a system to be performed in order to maintain the present level of performance/availability. Such a 25-year consolidation program was put in place at CERN before the LIU project was launched, and there are numerous items which need to be consolidated in order to ensure reliable operation of the LHC injectors throughout the life time of the LHC, regardless of upgrade scenarios. A typical example is the replacement of the PSB multipole power converters. Pure upgrade refers to the replacement or addition of a system to improve the performance, which would otherwise not be necessary. Examples are the H injection equipment in the PSB, or the modifications of the PS injection for 2 GeV. Performance improving consolidation (PIC) terms the replacement or upgrade of a system justified by consolidation but with the goal of improving performance. An example would be the change of an ageing PSB power supply by a new one which is more reliable and which can also operate at 2 GeV beam energy. Using this definition of PICs, there is significant overlap both towards consolidation and upgrade. Items which fall in these grey areas will be highlighted in the following sections. LIU-PSB In the following sections we list the PIC items of the LIU-PSB project, we address the risks and give a cost and time estimate. Magnets While the modification of the main dipoles (improved water cooling, shimming, retaining plates) is only required for the 2 GeV upgrade and hence a pure upgrade item, some of the magnets in the injection line and in the transfer line to the PS can be considered PIC items. A number of quadrupoles in the BI line are pure consolidation items which need to be changed in all possible scenarios. The partial replacement of magnets in the transfer line to the PS is a combination of consolidation and upgrade and hence a PIC item. The risk of not doing the consolidation consists in magnet failure and unsatisfactory spare situation, in particular for BT.BHZ10. The risks associated with changing the magnets are related to the transport and handling. Presently there is no lifting equipment which can access and handle the heavy dipole magnets. A study is in progress to assess this issue. RF Systems The low-level RF of the PSB is at the same time obsolete and inappropriate for future operation with Linac4 and the new high-level RF system. Recommissioning of the new system will be needed. The renovation of the high-level RF system consists in replacing the C02 and C04 cavities by new Finemet cavities. The old system is obsolete and will not work with Linac4 intensities and 2 GeV. The new RF system can partially be tested before full installation (prototype cavities in ring 3), but since installation of all required cavities will require removal of the present system, a full test cannot be done beforehand. Further to that technical issues need still to be addressed, e.g. impedance. Power Converters The replacement of power converters in the injection line is purely related to Linac4 connection and hence not considered a PIC. However a number of power converters in the rings and notably in the extraction and transfer line can be considered PIC items. Also the main power supply (MPS) can be considered a PIC item, since partial consolidation of the existing MPS would be necessary if it was to continue operation. In particular consolidation of the static VAR compensators (SVC) had been budgeted before the energy upgrade was discussed. Obviously the consolidation part of the budget is small w.r.t. the overall Published by CERN in the Proceedings of RLIUP: Review of LHC and Injector Upgrade Plans, Centre de Convention, Archamps, France, 29–31 October 2013, edited by B. Goddard and F. Zimmermann, CERN–2014–006 (CERN, Geneva, 2014) 978-92-9083-407-6, 0007-8328 – c © CERN, 2014. Published under the Creative Common Attribution CC BY 4.0 Licence. http://dx.doi.org/10.5170/CERN-2014-006.39 39 cost of a new MPS (3 MCHF compared to a total of 15 MCHF, see section Cost). Beam Instrumentation Beam instrumentation is also widely a PIC item, since consolidation needs and increased requirements in the frame of the upgrade project are almost inseparable. Main items are the new wire scanners, the new orbit system and replacement/increased number of BLMs. The shortcomings of the present systems are the insufficient transverse emittance diagnostics (improved precision needed for future high brightness LHC beams) and insufficient BLM coverage for operation with Linac4. As any new development the new systems need to be commissioned and tested, where possible before Linac4 connection. The main risk is that this will not be fully possible, which can impact the commissioning time after LS2. PSB Dump While the injection dumps are only required for Linac4, and therefore a pure upgrade item, the main dump of the PSB can be considered a PIC. The old dump was in place since the construction of the Booster, and is inappropriate for the intensities expected with Linac4 and 2 GeV beam energy. The dump was replaced by a new one during LS1, this item is therefore completed. There is no risk identified for the operation with the new dump. Extraction and Transfer There are reliability and spare issues with some of the extraction and transfer line equipment. This will be addressed at the same time as doing the upgrade to 2 GeV beam energy. The new systems will need to be commissioned, and potential issues with the rise time of the extraction kickers are being addressed. Cooling and Ventilation The present system is obsolete and a complete renovation is planned, taking into account the new requirements of an upgraded Booster. This comprises cooling for the new MPS, the new dump, and increased cooling of the main magnets. The CV system is also closely related to RP issues (evacuation of irradiated air). The renovation of the cooling and ventilation system is a potential time driver for LS2. Transport and Handling Equipment The entire transport and handling equipment must be renovated in order for it to be ready for the upgrade work planned in the PSB. If the renovation is not done, delays are to be expected for LS2. Studies are needed for removal/installation of the new dump (completed), and for the lifting of some equipment e.g. the large bending magnets in the BTM and BT line. In particular for these dipole magnets presently no handling equipment exists, and studies are underway. Cost Table 1 shows the cost overview of the beforehand mentioned LIU-PSB PIC items. Table 1: Cost of LIU-PSB PIC items