LIU, ABP-CWG, PBC, miscellaneous ABP-HSC Section meeting, 10.07.2017 https://indico.cern.ch/event/640326/

LIU (LHC Injectors Upgrade) Meeting on LIU Beam Parameter WG on 30 June (Indico link) Discussion on tune variation with injection bump in PS Swing by 0.01 during fall of injection bump (over 2 ms now, 1 ms in future) Could it be responsible for the horizontal emittance blow up observed in the 2016 data of the LHC beam emittance along the injector chain? Needs to be studied in detailed space charge simulations together with mismatch/mis-steering at injection Next meeting at the end of July for a mid-year review of the status of the MDs related to LIU LIU/HL-LHC Executive Committee meeting last week was mainly on HL-LHC questions, however one issue was discussed for LIU Swap of 2021 Pb ion run with 2023 p-p reference run, needed to relieve beam commissioning after LS2 and allow for more time for slip stacking commissioning, still under discussion. Extended LIU summaries for the year 2016 needed for Long article for September issue of the CERN Courier (in the general framework of the CERN upgrade programs) BE Annual Report

PBC (Physics Beyond Colliders) Presentation on non-LHC beam after LIU given at IEFC on 7 July (Indico link) Quick summary of LIU program and performance reach for LIU beams Highlighted that both standard and BCMS beams should be taken into consideration after Chamonix discussions, persisting question on BCMS intensity reach due to limitation in protection devices Preliminary analysis of other types of beams ISOLDE potentially to 1.6e13 p/ring, however limitations to be further studied nTOF could go to >1e13 pot/shot with new target, but also limited by TMCI at transition, RF power for rotation, losses on extraction septum (space charge?) AD could be relieved from transient beam loading due to 1T delay feedbacks, but can it be used? SPS FT physics with Beam Dump Facility will require high intensity (CNGS- like) for slow extraction over 1 s. A few questions on production scheme in PSB, high intensity MTE, losses in LSS2 (SPS) AWAKE will profit from RF upgrade and longitudinal impedance reduction in SPS, but other limitations for INDIV-type beams in pre-injectors? Main question to address is the production of all these beams in the PSB in Linac4 era (potentially double brightness?) and the transport of the achievable intensity/brightness

ABP-CWG Meeting last Thursday 6 July, 2017 (Indico link) Miscellaneous Mixed experience with HTCondor so far, maybe more feedback needed to iterate with IT HPC in CNAF (Bologna) set up: For the moment 12/20 nodes available (32 cores each) Gianni and Annalisa are running e-cloud simulations and using the full cluster, Annalisa presented simple instructions how to submit jobs to this cluster Benchmark jobs as foreseen in Collaboration Agreement have been successfully run (note to be published this week), Continuation of the set up of the cluster is presently under discussion due to gpu need and few options are being explored to make the best use of the available money. However, probably more financing in the order of 50 kCHF will be needed An email will be sent to abp-cwg-all to point to Annalisa’s presentation and provide directions how to obtain an account at the cluster HPCs at CERN also progressing: Order gone out for 2x 72 (2x E5-2630v4 CPU) nodes (20 cores each) – which will mean 1440 cores per cluster

ABP-CWG Meeting last Thursday 6 July, 2017 (Indico link) Presentation on SIRE (S. Papadopoulou) Simplified IBS model without real transport along ring, can take into account arbitrary distributions (not only Gaussian) and fits LHC data well with reasonable running times for most of the machines under consideration (LHC, HL-LHC, CLIC camping rings, FCC) Any improvement to study IBS together in combination with other effects (e.g. space charge, nonlinearities, e-cooling), which could be important for LEIR, PS, SPS with ions, would require important resources Next meeting again on Thursday 20 July with Introduction to CNAF cluster and PyTimber & PyLSA (Riccardo)