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This note contains a condensed summary of the various beam tests which took place in 2022 in order to validate the machine configuration planned to be deployed for the 2023 proton run of the LHC, including in particular a combined ramp and anti-telescopic squeeze, the rotation of the external crossing angle in LHCb, and beam operation with up to 1.8 × 1011 p/b.

The High Luminosity Large Hadron Collider (HL--LHC) will require unprecedented orbit stability at the low-beta experiments, ATLAS and CMS. Because the effect of seismic noise might become a relevant source of luminosity loss, several studies have been conducted to characterize the actual ground motion in the LHC tunnel. In preparation for the official groundbreaking of the civil engineering work for the high luminosity upgrade, which started on 15 June 2018 in parallel to LHC beam operation, seismic sensors were installed to permanently monitor the ground stability close to these experiments. Compactor work and shaft excavation were expected to induce vibrations in the accelerator magnets that would cause orbit disturbance, beam loss, and potentially premature beam dumps. This paper summarises the observations made on the LHC beams and uses this data to benchmark estimates of the impact of low-frequency vibrations on the closed orbit at the main interaction points and collimators. The impact of ground motion on HL--LHC operation is then estimated using the expected operational scenario and the estimated mechanical stability of the new HL--LHC triplet magnets that is based on recent measurements of mechanical magnet transfer functions.

Following new findings in beam dynamics and the latest HL-LHC project decisions, an operational scenario has been developed for the first HL-LHC run, Run 4. This new scenario is presented in this document along with the motivations for the proposed changes and performance estimates.

Understanding and mitigating particle losses in the Large Hadron Collider (LHC) is essential for both machine safety and efficient operation. Abnormal loss distributions are telltale signs of abnormal beam behaviour or incorrect machine configuration. By leveraging the advancements made in the field of Machine Learning, a novel data-driven method of detecting anomalous loss distributions during machine operation has been developed. A neural network anomaly detection model was trained to detect Unidentified Falling Object events using stable beam, Beam Loss Monitor (BLM) data acquired during the operation of the LHC. Data-driven models, such as the one presented, could lead to significant improvements in the autonomous labelling of abnormal loss distributions, ultimately bolstering the ever ongoing effort toward improving the understanding and mitigation of these events., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

In this contribution we provide a summary of the LHC hardware commissioning campaign following the second CERN Long Shutdown (LS2), initially targeting the nominal LHC energy of 7 TeV. A summary of the test procedures and tools used for testing the LHC superconducting circuits is given, together with statistics on the successful test execution. The paper then focuses on the experience and observations during the main dipole training campaign, describing the encountered problems, the related analysis and mitigation measures, ultimately leading to the decision to reduce the energy target to 6.8 TeV. The re-commissioning of two powering sectors, following the identified problems, is discussed in detail. The paper concludes with an outlook to the future hardware commissioning campaigns, discussing the lessons learnt and possible strategies moving forward., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

This work presents an extensive overview of the design choices and implementation of the Beam-Based Feedback System (BBFS) used in operation until the LHC Run 2. The main limitations of the BBFS are listed and a new design called BFCLHC, which uses the CERN Front-End Software Architecture (FESA), framework is proposed. The main implementation details and new features which improve upon the usability of the new design are then emphasised. Finally, a hardware agnostic testing framework developed by the LHC operations section is introduced., Proceedings of the 18th International Conference on Accelerator and Large Experimental Physics Control Systems, ICALEPCS2021, Shanghai, China

A new scenario for the first operational run of the HL-LHC era (Run 4) has been recently developed to accommodate a period of performance ramp-up to achieve an annual integrated luminosity close to the nominal HL-LHC design. The operational scenario in terms of beam parameters and machine settings, as well as the different phases, are described here along with the impact of potential delays on key hardware components., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

This document summarises the LHC Machine Development session on colliding at β∗ = 1 m and squeezing with colliding beams to β∗ = 25 cm in IP 1 and 5 using the capabilities of the LumiServer. To do so, the beams were brought into collision at the end of the ramp without playing the regular squeeze to 30 cm. Once in collision, the β∗ levelling functionality of the LumiServer was used to squeeze and de-squeeze the beams in two cycles between β∗ = 1 m and β∗ = 25 cm. After each squeeze step, a luminosity optimization scan was performed in IP 1 and 5 to assess the orbit stability, ensuring that the beams remained in collisions.

After its second successful run period, the Large Hadron Collider (LHC) shut down for three years with the plan of being recommissioned in 2022 for a three-year physics production period, the Run 3. The future restart of the machine coincides with the completion of the LHC Injectors Upgrade (LIU) project, offering to the LHC the opportunity and the challenge to operate with up to two times higher beam brightness, pending the complete installation of the High-Luminosity LHC (HL-LHC), which should take place in Long Shutdown 3 (LS3). In this context, Run 3 is clearly a transition between the LHC and the HL-LHC, with key ingredients which will be made available, either gradually (LIU beam) or immediately (ATS optics). Run 3 shall therefore be exploited not only for performance, but also as a full scale demonstrator of the HL-LHC in terms of beams, optics and beam manipulation (e.g. β∗ levelling over a very large dynamic range). To this aim, the so-called LHC configuration, namely the optics, needs to be adapted in order to cope or mitigate constraints of different nature, from beam brightness limitations due to the machine impedance, to specific desiderata of some LHC experiments. After reviewing these constraints, including the intensity limitations coming from the existing hardware, the beam parameters targeted for the LHC in Run 3 are given. A possible solution for the machine configuration will then be described, and analyzed from various perspectives, which should not limit the machine performance over the full Run 3, and should enable to double the integrated luminosity delivered so far to the two high luminosity insertions of the LHC.

This work presents an extensive overview of the design choices and implementation of the Beam-Based Feedback System (BBFS) used in operation until the LHC Run 2. The main limitations of the BBFS are listed and a new design called BFCLHC, which uses the CERN Front-End Software Architecture (FESA), framework is proposed. The main implementation details and new features which improve upon the usability of the new design are then emphasised. Finally, a hardware agnostic testing framework developed by the LHC operations section is introduced., peer-reviewed

In this report we assess the feasibility for installation of the $Nb_{3}$Sn MBH S2 magnet in the LHC and conclude on possible performance limitations.

Collective instabilities can lead to a severe deterioration of beam quality, in terms of reduced beam intensity and increased beam emittance, and consequently a reduction of the collider’s luminosity. It is therefore crucial for the operation of the CERN’s Large Hadron Collider to understand the conditions in which they appear in order to find appropriate mitigation measures. Using bunch-by-bunch and turn-by-turn beam amplitude data, courtesy of the transverse damper’s observation box (ObsBox), a novel machine learning based approach is developed to both detect and classify these instabilities. By training an autoencoder neural network on the ObsBox amplitude data and using the model’s reconstruction error, instabilities and other phenomena are separated from nominal beam behaviour. Additionally, the latent space encoding of this autoencoder offers a unique image like representation of the beam amplitude signal. Leveraging this latent space representation allows us to cluster the various types of anomalous signals., Proceedings of the 12th International Particle Accelerator Conference, IPAC2021, Campinas, SP, Brazil

The protection of the tertiary collimators (TCTs) and the LHC triplet aperture in case of a so-called asynchronous beam dump relies on the correct retraction between the TCTs and the dump region absorbers. A new method to validate this retraction has been proposed, and a proof-of-principle experiment was performed at the LHC. The method uses a long orbit bump to mimic the change of the beam trajectory caused by an asynchronous firing of the extraction kickers. It can, thus, be performed with circulating beam. This paper reports on the performed beam measurements, compares them with expectations and discusses the potential benefits of the new method for machine protection., Proceedings of the 12th International Particle Accelerator Conference, IPAC2021, Campinas, SP, Brazil

This paper highlights the outcome of the 2018 round ATS MD program, which aimed at demonstrating the feasibility of a combined ramp and telescopic squeeze as a potential key ingredient to operate the machine in Run 3, with much brighter and more energetic beams with respect to Run 2. The machine configuration which was used is first described in terms of hypercycle, optics transitions, and dedicated beam gymnastics. The various commissioning steps which were needed to obtain the green light for an intensity ramp up are described, in particular the optics measurements and corrections, the triplet aperture measurements, and the collimation-related activities. The main results are illustrated in terms of octupole threshold minimization, beam lifetime in the ramp with the machine filled with several hundred of nominal bunches or 8b4e bunch trains, and long-range beam-beam mitigation with lattice octupoles. A dedicated instability study on possible variants for the adjust beam process is also reported.

Luminosity levelling by β∗ is the baseline scenario for HL-LHC and will possibly be used in 2018 LHC operation. In this MD, we commissioned a novel controls approach to β∗ levelling using improved LSA trims and automatic orchestration. Compared to the regular squeeze using sequences, this approach is aimed to be minimally invasive to LHC operation in Stable Beams. Using this tool, we demonstrated the feasibility of β∗ levelling between 1 m and 30 cm.

The betatron tune in the Large Hadron Collider (LHC) is measured using a Base-Band-Tune (BBQ) system. Processing of these BBQ signals is often perturbed by 50Hz noise harmonics present in the beam. This causes the tune measurement algorithm, currently based on peak detection, to provide incorrect tune estimates during the acceleration cycle with values that clearly oscillate between neighbouring harmonics. The LHC tune feedback cannot be used to its full extent in these conditions as it relies on stable and reliable tune estimates. In this work we present two alternative tune measurement algorithms, designed to mitigate this problem by ignoring small frequency bands around the 50Hz harmonics and estimating the tune from spectra with gaps. One is based on Gaussian Processes and the other is based on a weighted moving average. We compare the tune estimates of the new and present algorithms and put forward a proposal that can be implemented during the renovation of the BBQ system for the next physics run of the LHC., Proceedings of the 9th International Beam Instrumentation Conference, IBIC2020, Santos, Brazil

Orbit correction in accelerators typically make use of a linear model of the machine, called the Response Matrix (RM), that relates local beam deflections to position changes. The RM is used to obtain a Pseudo-Inverse (PI), which is used in a feedback configuration, where positional errors from the reference orbit as measured by Beam Position Monitors (BPMs) are used to calculate the required change in the current flowing through the Closed Orbit Dipoles (CODs). The calculation of the PIs from the RMs is a crucial part in the LHC’s Orbit Feedback Controller (OFC), however in the present implementation of the OFC this calculation is omitted as it takes too much time to calculate and thus is unsuitable in a real-time system. As a temporary solution the LHC operators pre-calculate the new PIs outside the OFC, and then manually upload them to the OFC in advance. In this paper we aim to find a solution to this computational bottleneck through hardware acceleration in order to act automatically and as quickly as possible to COD and/or BPM failures by re-calculating the PIs within the OFC. These results will eventually be used in the renovation of the OFC for the LHC’s Run 3., Proceedings of the 17th International Conference on Accelerator and Large Experimental Physics Control Systems, ICALEPCS2019, New York, NY, USA

Electron cloud (e-cloud) effects are among the main performance limitations for the operation of the Large Hadron Collider (LHC) with 25 ns bunch spacing. A large number of electrons impacting on the beam-screens of the superconducting magnets induces significant heat load, reaching values close to the full cooling capacity available from the cryogenic system. A number of Machine Development (MD) sessions in 2018 was dedicated to characterizing the heat load as a function of beam and machine parameters, investigating in particular its distribution along the ring and its dependence on the filling pattern, bunch population and bunch length. The main results of these measurements have been compared against simulations performed with the PyECLOUD code in order to validate the underlying model.

Since the beginning of the LHC commissioning, harmonics of 50 Hz have been observed in the beam spectrum. Several observations during the 2018 proton run show that these harmonics are the result of a real beam excitation, rather than an artifact of the instrumentation system. As many of these components reside in the vicinity of the betatron tune, their presence can complicate the tune measurement and tracking during operation and potentially lead to beam losses and emittance growth. This note summarizes the program of the first LHC Machine Development (MD) (Fills 7342 and 7343) dedicated to the investigation of this effect. The aim of this study is to reproduce some of the observations acquired during End-of-Fill experiments and parasitic observations, as well as to simulate the impact of dipolar noise on the beam with controlled ADT excitations.

In the very unlikely event of a non-working beam dumping system in the LHC, the up to 360 MJ (680 MJ for HiLumi) of beam energy per beam can be dissipated in the collimation system as a last alternative to an extraction into the beam dump. As this is a procedure with many machine protection implications, it was tested in a dedicated MD before detailed steps and parameters could be established for an eventual operational use. This note summarizes the results of tests with proton beams, at injection energy and 6.5 TeV, which demonstrate the possibility of disposing of the full beam and will allow defining such parameters.

Orbit correction in accelerators typically make use of a linear model of the machine, called the Response Matrix(RM), that relates local beam deflections to position changes.The RM is used to obtain a Pseudo-Inverse (PI), which is used in a feedback configuration, where positional errors from the reference orbit as measured by Beam Position Monitors (BPMs) are used to calculate the required change in the current flowing through the Closed Orbit Dipoles (CODs).The calculation of the PIs from the RMs is a crucial part in the LHC’s Orbit Feedback Controller (OFC), however in the present implementation of the OFC this calculation is omitted as it takes too much time to calculate and thus is unsuitable in a real-time system. As a temporary solution the LHC operators pre-calculate the new PIs outside the OFC, and then manually upload them to the OFC in advance. In this paper we aim to find a solution to this computational bottleneck through hardware acceleration in order to act automatically and as quickly as possible to COD and/or BPM failures by re-calculating the PIs within the OFC. These results will eventually be used in the renovation of the OFCfor the LHC’s Run 3., peer-reviewed

On 25 July 2018 partially stripped lead ions with one remaining electron (208Pb81+) were injected, accelerated and stored in the LHC for the first time in the scope of MD3284. Lifetimes of about 20 hours at injection and 50 hours at 6.5 TeV proton equivalent energy could be observed. The MD revealed that losses in cell 11R7 (dispersion suppressor adjacent to the collimation insertion in point 7) are stronger than expected. This note summarises the detailed programme and results of the MD.

The paper reports on the first high-intensity beam tests obtained with flat optics in 2018 (MD2148). This new machine configuration is described in terms of hypercycle, optics transitions, and dedicated beam gymnastics. The various commissioning steps which were needed to obtain the green light for an intensity ramp up are highlighted, in particular the optics measurements and corrections, the triplet aperture measurements, and the collimation-related activities. First collision of trains took place in the second 2018 LHC MD block. The main results are given in terms of luminosity, long-range beam-beam mitigation with lattice octupoles, and corresponding crossing angle reach.

Between 2015 and 2018 the LHC was operated with protons at beam energies of 6.5 TeV with an integrated production of 160 fb-1 both ATLAS and CMS in proton operation. The peak proton performance exceeded twice the design luminosity thanks to very small transverse beam emittances and beta* of 30 cm. The nominal bunch spacing of 25 ns was used for high intensity operation, initially with the standard 25 ns beam and from 2016 onwards with BCMS and 8b4e beams. New features such as combined ramp and squeeze, crossing angle and levelling as well as ATS optics (Achromatic Telescopic Squeeze) were introduced in regular operation between 2016 and 2018. Lead ion, mixed proton-lead, intermediate proton energy, vdm calibration and high-beta runs were also performed with a large diversity of configurations and beam energies. This note summarizes LHC operation during Run 2 and documents in detail the congurations and performances achieved for the various operation modes.

This report discusses the feasibility and limitations for operating the LHC and HL-LHC at the ultimate beam energy of 7.5 TeV, corresponding to a main dipole magnetic field of 8.93 T and an operating current of 12748 A.

The official groundbreaking of the civil engineering (CE) work for the high luminosity upgrade of the LHC started on 15 June 2018 parallel to LHC beam operation. Compactor work and shaft excavation around the two low beta experiments, ATLAS and CMS, were expected to induce vibrations to the accelerator magnets and cause orbit disturbance, beam loss and potentially premature beam dumps. Ground motion sensors were installed on the surface and close to the triplets, where the CE works were expected to have the largest impact on the beams. This paper discusses the observations made on the LHC beams that could be correlated to CE work., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

The fourth one-month Pb-Pb collision run brought LHC Run 2 to an end in December 2018. Following the tendency to reduce dependence on the configuration of the preceding proton run, a completely new optics cycle with the strongest ever focussing at the ALICE and LHCb experiments was designed and rapidly implemented, demonstrating the maturity of the collider’s operating modes. Beam-loss monitor thresholds were carefully adjusted to provide optimal protection from the multiple loss mechanisms in heavy-ion operation. A switch from a basic bunch-spacing of 100 ns to 75 ns was made as the beam became available from the injector chain. A new record luminosity, 6 times the original design and close to the operating value proposed for HL-LHC, provided validation of the strategy for mitigating quenches due to bound-free pair production (BFPP) at the interaction points of the ATLAS and CMS experiments. Most of the beam parameters of the HL-LHC Pb-Pb upgrade were attained during this run and the integrated luminosity goals for the first 10 years of LHC operation were substantially exceeded., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

This document discusses the machine parameters and expected luminosity performance for the proposed future circular lepton collider FCC-ee. Particular emphasis is put on availability, physics run time, and efficiency. Key performance assumptions are compared with the operational experience of several past and present colliders including their injectors - LHC, LEP/LEP-2, PEP-II, KEKB, BEPCII, DAΦNE, SLC and the SPS complex., Proceedings of the 62th ICFA ABDW on High Luminosity Circular e$^+$e$^-$ Colliders, eeFACT2018, Hong Kong, China

LHC Run 2 has achieved a beta lower than a factor 2 below design. This has significantly challenged optics measurement and correction techniques in the linear and non-linear regimes, leading to the development of new approaches. Furthermore, experimenting with a large variety of optics has allowed facing the difficulties of future optics and gaining understanding of the machine imperfections. A summary of these aspects is given in view of their implications for the HL-LHC Project., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

The Gamma Factory initiative proposes to use partially stripped ion (PSI) beams as drivers of a new type of high intensity photon source. As part of the ongoing Physics Beyond Collider studies, initial beam tests with PSI beams have been executed at CERN. On 25 July 2018 lead ions with one remaining electron (208Pb⁸¹⁺) were injected and accelerated in the LHC for the first time. After establishing the injection and circulation of a few 208Pb⁸¹⁺ bunches, beam lifetimes of about 50 hours could be established at 6.5 TeV proton equivalent energy. This paper describes the setup of the beam tests and observations made., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

The Gamma Factory initiative proposes to use partially stripped ion (PSI) beams as drivers of a new type of high intensity photon source. As part of the ongoing Physics Beyond Collider studies, initial beam tests with PSI beams have been executed at CERN. On 25 July 2018 lead ions with one remaining electron ($^{208}$Pb$^{81+}$) were injected and accelerated in the LHC for the first time. After establishing the injection and circulation of a few $^{208}$Pb$^{81+}$ bunches, beam lifetimes of about 50 hours could be established at 6.5 TeV proton equivalent energy. This paper describes the setup of the beam tests and observations made.

LHC Optics Measurements and Corrections (OMC) require efficient on-line software applications to acquire and analyze data and to compute the necessary corrections. During Run 2 various measurement and correction techniques have been merged to yield unprecedented optics quality, increasing the required number of steps to finalize the optics commissioning and the size of the software project. In turn, this calls for a higher level of automation, where machine learning techniques are being implemented. During the Long Shutdown 2 a large refactoring of the codes will be in place to improve performance, maintainability and extensibility. A description of the current status of the software and future plans is given., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

The LHC turn-around time is impacted by the control of injection losses and trajectories. While shot-to-shot trajectory variations dominated the injection efficiency during LHC Run 1, several improvements of hardware and operational settings allowed for a high rate of successful injections during Run 2. Injection losses and trajectories are analysed and presented for the high intensity proton runs, as well as for different beam types used from the injectors. Based on this analysis, an outlook is shown for the HL-LHC era, where double the bunch intensity will have to be injected., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

Run 2 of the CERN Large Hadron Collider (LHC) was successfully completed on 10th December 2018, achieving largely all goals set in terms of luminosity production. Following the first two-year long shutdown and the re-commissioning in 2015 at 6.5 TeV, the beam performance was increased to reach a peak luminosity of more than twice the design value and a colliding beam time ratio of 50%. This was accomplished thanks to the increased beam brightness from the injector chain, the high machine availability and the performance enhancements made in the LHC for which some methods and tools, foreseen for the High Luminosity LHC (HL-LHC) were tested and deployed operationally. This contribution provides an overview of the operational aspects, main limitations and achievements for the proton Run 2., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

The Large Hadron Collider (LHC) has successfully completed its second operational run of four years length in December 2018. Operation will be stopped during two years for maintenance and upgrades. To allow for the successful completion of the diverse physics program at 6.5 TeV, the LHC has been routinely operating with stored beam energies close to 300 MJ per beam during high intensity proton runs as well as being frequently reconfigured to allow for special physic runs and important machine developments. No significant damage has incurred to the protected accelerator equipment throughout the run thanks to the excellent performance of the various machine protection systems, however a number of important observations and new failure scenarios have been identified, which were studied experimentally as well as through detailed simulations. In this contribution, we provide an overview of the performance of the machine protection systems throughout Run 2 as well as the important lessons learnt that will impact consolidation actions and the upgrade of the machine protection systems for the LIU/HL-LHC era., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

This paper highlights the main results from the 2017 LHC MD program which was deployed to commission round ATS optics with high telescopic index, and ultimately to study their properties in terms of long-range beam-beam effect and octupole thresholds for coherent instabilities (MD2269). This has been the fruit of a long work all along 2017, but in the end and for the first time, a dedicated LHC MD program (4 shifts in total) opened the possibility to study a non-nominal machine configuration with unsafe beams, and then extract from this study a myriad of very conclusive results for the future operation of the LHC.

The Schottky monitors installed at the LHC enable the detection of Schottky noise of the two circulating proton / ion beams. From Schottky noise, beam parameters like tune, chromaticity, and relative emittance, can be extracted in a non-destructive and purely parasitic method of measurement. The primary goal of this MD was to study the Schottky monitors capability to reliably and accurately determine the beam chromaticities at injection energy. Furthermore, the possibility to track the beam emittance has been investigated.

In 2016 the luminosity reach of the LHC was increased by reducing the β-function in the main collision points below the design value to β∗ = 40 cm. This was possible due to a review of the margins in the collimation hierarchy followed by the implementation of additional measures to ensure the phase advance in defined ranges around the circumference. The risk of damaging the triplet or the tertiary collimators (TCTs) close to the interaction points in the event of an asynchronous beam dump is minimized by including margins in the collimation hierarchy, which define the β∗-reach. By guaranteeing the phase advance within an acceptable tolerance between the beam dump kicker and the TCTs, those margins can be reduced and operation at lower β∗ becomes possible. A new interlock system on the quadrupole magnet currents was put in place to safeguard the stability of the phase advance. This note describes the technical implementation of this power-converter interlock (PcInterlock) and the strategies used to derive appropriated tolerances to allow sufficient protection without risking false beam dump triggers. The experience with the new PcInterlock settings in 2016-18 are discussed.

Recurrent beam dumps significantly perturbed the operation of the CERN LHC in the summer months of 2017, especially in August. These unexpected beam dumps were triggered by fast beam losses that built up in the cryogenic beam vacuum at the half-cell 16 left of LHC-IP2 and were detected either at that location but mainly in the collimation insertions. This contribution details the experimental observables (beam losses, coherent instabilities, heat load to cryogenic system, vacuum signals), the extent of the understanding of the beam loss and instability mechanisms and the mitigation steps and new settings that allowed recovering the luminosity performance of the LHC for the rest of the Run., Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada

The LHC is now operating with a tune separation of ∼0.004 in collision. This puts tight constraints on the allowed transverse coupling since a |C−| larger than a fraction of the fractional tune split may lead to beam instabilities. In the last years a new tool based on the ADT used in a similar way as an AC-dipole to excite the beam was developed. The ADT AC-dipole gives coherent oscillations without increasing the beam emittance. These oscillations are analyzed automatically to obtain the value of the coupling. A coupling measurement campaign was done in 2017 and while the correction converged and stayed rather constant over time it was observed that depending on the target bunch and filling scheme the results could vary by Δ|C−| ∼ 0.002. In this MD report we investigated 3 different bunches, one with Long Range Beam-Beam (LRBB) in IPs 1 and 5, one with LRBB in all IPs and one with no LRBB. The results indicate that there are differences in coupling between the bunches experiencing different LRBB. Furthermore, there is also a measurable difference in the tunes between the different bunches. A measurement of the emittance also shows that there is no observable increase of emittance from these measurement techniques.

Measurements performed with a Parabolic Parabolic Linear Parabolic (PPLP) momentum function in the LHC. Three attempts have been performed with a pilot bunch and one with nominal bunch (1.1x1011 p/bunch).

The CERN Large Hadron Collider Run II saw an important increase in beam performance through both, improvements in the LHC and an increased beam brightness from the injectors, leading to a peak luminosity that exceeds the LHC design luminosity by more than a factor two. This contribution will give an overview of run 2, the main challenges encountered and it will address the measures applied to deal with and make use of the increased beam brightness. Finally potential areas where further performance improvement can be a realized will be identified., Proceedings of the 61\textsuperscript{st} ICFA ABDW on High-Intensity and High-Brightness Hadron Beams, HB2018, Daejeon, Korea

The High Luminosity LHC (HL-LHC) will require unprecedented orbit stability at the low beta collision points (IP1 and IP5), and the effect of seismic noise might become a relevant source of luminosity loss. Many studies have been conducted in the past to characterise the actual ground motion in the LHC tunnel, and recently a few geo-phones have been installed to permanently monitor the ground stability at IP1 and IP5. An estimate of the impact of the main machine element vibration on orbit at the IPs and collimators is presented, together with a first look at the data collected by the installed geo-phones., Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada

In 2017, the CERN accelerator complex once again demonstrated its flexibility by producing beams of a new ion species, xenon, that were successfully injected into LHC. On 12 October, collisions of fully stripped xenon nuclei were recorded for the first time in the LHC at a centre-of-mass energy per colliding nucleon pair of 5.44 TeV. Physics data taking started 9.5 h after the first injection of xenon beams and lasted a total of 6 h. The integrated luminosity delivered to the four LHC experiments was sufficient that new physics results can be expected soon. We provide a general overview of this Xe-Xe pilot run before focussing on beam data at injection energy and at flat-top., Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada

The FCC-ee Lepton Collider will provide e⁺e⁻ collisions in the beam energy range of 45.6 GeV to 182.5 GeV. FCC-ee will be a precision measurement tool for Z, W, H and t physics with expected luminosities of 2.07× 10³⁶ cm⁻² s⁻¹ at the Z-pole and 1.3 × 10³⁴ cm⁻² s⁻¹ at the tt⁻ threshold. In order to achieve the foreseen luminosities, a vertical β^{*} of 1 mm to 2 mm is mandatory. Dynamic aperture and frequency map analysis for the 97.75 km machine with such a squeezed accelerator optics are studied. Furthermore, effects of machine misalignments on dynamic and momentum aperture are presented and estimations for the required tolerances are given, Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada

HL-LHC requires the excavation of large underground infrastructures in order to host new equipment. The tunnel shall be ready for installation for LS3 (2022) and therefore its construction shall take in place in parallel with the LHC exploitation. Effect of vibrations induced by civil engineering activities need to be evaluated in order to take required corrective actions. For this purpose, several diverse measurements and experiments have been performed in order to estimate the vibration sources and determine the vibration transfer path through the floor and the structure. The transfer functions from amplitude and phase point of view were determined through molasses rock, for both horizontal and vertical vibrations, with dedicated tools and Experimental Modal Analysis was carried out on mechanical structure. The campaign of measurements have been used to confirm the effect of the surface induced vibration on the circulating beam orbit at the resonance frequencies of the structure. This paper reviews the advanced technique of measurements, results and the conclusion about the impact of operating civil engineering machines (road header, hydraulic hammer) during beam exploitation., Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada