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GE1/1 Performance using 2023 p-p collision data at TeV
No full textThis study presents the muon detection efficiency of the GE1/1 detectors in a boson enriched data sample corresponding to 17.8 fb of data collected at TeV during 2023. The muons are reconstructed with the global CMS detector, excluding the GE1/1 detectors themselves to avoid biasing the results, and compatible hits are searched for. Muon residual distributions of the compatible hits are also presented. The detection efficiencies are presented per chamber and per front-end readout chip (VFAT) to give a more granular view of the detector, and also as a function of pile-up
CMS BRIL -Z PLT/BCM1F/BCM1L Transport and Installation
No full textTransport and Installation of the -Z replacement of the Beam Condition Monitor "Fast" (BCM1F), the Beam Condition Monitor for Losses (BCM1L), and the Pixel Luminosity Telescope (PLT) sub-systems
Charge calibration of MALTA2, a radiation hard depleted monolithic active pixel sensor
No full textMALTA2 is a depleted monolithic active pixel sensor (DMAPS) designed for tracking at high rates and typically low detection threshold of . A precise knowledge of the threshold is crucial to understanding the charge collection in the pixel and specifying the environment for sensor application. A simple procedure is developed to calibrate the threshold to unit electrons making use of a dedicated charge injection circuit and an Fe-55 source with dominant charge deposition of . The injection voltage is determined which corresponds to the injection under Fe-55 exposure and is the basis for charge calibration. The charge injection circuit incorporates a capacitance with design value of 230 aF. Experimentally, the average capacitance value for non-irradiated samples is found to be 257 aF. The 12 % divergence motivates the need for the presented precise calibration procedure, which is proposed to be performed for each MALTA2 sensor
Leveraging the Run 3 experience for the evolution of the ATLAS software-based readout towards HL-LHC
No full textThe High-Luminosity Large Hadron Collider (HL-LHC), scheduled to start operating in 2029, aims to increase the instantaneous luminosity by a factor of 10 compared to the LHC. To match this increase, the ATLAS experiment has been implementing a major upgrade program divided into two phases. The first phase (Phase-I), completed in 2022, introduced new trigger and detector systems that have been used during the Run 3 data taking period which began in July 2022. These systems have been used in conjunction with the new Data Acquisition (DAQ) Readout system, based on a software application called Software Readout Driver (SW~ROD). SW~ROD receives and aggregates data from the front-end electronics via the Front-End Link eXchange (FELIX) system and passes aggregated data fragments to the High-Level Trigger (HLT) system. During Run 3, SW~ROD operates in parallel with the legacy Readout System (ROS) at an input rate of 100 kHz. For the Phase-II, the legacy ROS will be completely replaced with a new system based on the next generation of FELIX and an evolution of the SW~ROD application called Data Handler. Data Handler has the same functional requirements as SW~ROD but must be able to operate at an input rate of 1 MHz. To facilitate this evolution the SW~ROD has been implemented using plugin architecture. This contribution presents the design and implementation of the SW~ROD application for Run 3, along with the strategy for its evolution to the Phase-II Readout system. It discusses the lessons learned during Run~3 and describes the challenges that have been addressed to accomplish the demanding performance requirements of HL-LHC
ALICE Forward Calorimeter upgrade (FoCal): Physics program and performance
No full textA new high-precision forward calorimeter (FoCal) is about to be installed in the ALICE experiment at the LHC during Long Shutdown 3 for data-taking in the LHC Run 4 that is currently scheduled for the period 2030-2033. FoCal consists of a Si+W sampling electromagnetic calorimeter with longitudinal and transverse segmentations (FoCal-E) and a conventional Cu+scintillating-fiber hadronic calorimeter (FoCal-H). FoCal has a front face of approximately 90 90 cm and isplaced at z 7 m from the nominal interaction point. It covers the pseudo-rapidity range of 3.2 5.8. FoCal has unique capabilities to measure the direct photon production at the forward rapidity that probes the gluon distribution in protons and nuclei at small-. Furthermore, FoCal will enable to carry out inclusive and correlation measurements of photons, neutral mesons and jets in hadronic pp and p-Pb collisions aswell as J/ production in the ultra-peripheral p-Pb and Pb-Pb collisions. We developed a full-length detector prototype and studied its performance such as a response to minimum ionizing particles and a longitudinal shower profile of electromagneticshowers at the CERN PS and SPS complexes in 2022-2023. We tested the silicon pad sensors for FoCal-E at the RIKEN Accelerator-driven compact neutron systems (RANS) facility in Japan in 2022-2024 and they have the radiation tolerance to withstand the full operation at the LHC Run 4.Mass production of FoCal will begin soon
Performance of a HL-LHC NbSn Quadrupole Magnet in the 100–200 MPa Range of Azimuthal Stress
No full textWith the assembly and test results of four NbSn short-model quadrupoles (MQXFS) for the High Luminosity Upgrade of the CERN Large Hadron Collider (LHC), an optimum pre-load level was established for the construction of the full-length, series magnets. Successive MQXFS magnets were used as testbeds for potential changes (including pre-load fine tuning) to be implemented in the series, and to better understand the stress dependence of NbSn magnet performance. In this paper we report the findings of the short model MQXFS7, where we investigated the effect of higher azimuthal pre-load on the performance of this magnet assembled with coils wound from NbSn Restacked-Rod-Process (RRP) conductors, which are the baseline for MQXF magnets, and Powder-In-Tube (PIT) conductors, which were initially considered as a potential candidate but subsequently set aside. Starting at the baseline level of 110 MPa azimuthal preload at 1.9 K (corresponding to a full preload at nominal current, which is 77% of the short sample limit at 1.9 K), we increased the pre-load in steps of 20 MPa up to 190 MPa. The magnet was able to operate above 90% of the short sample limit indicating a large range of possible preloads. Indications of performance degradation at 90-95% of the short sample limit were found in the PIT conductor at 170 and 190 MPa. The test included a significant set of observables, such as the ramp rate dependency on the quench current, and V-I measurements to see growing resistance in segments of the coil
A compact frozen-spin trap for the search for the electric dipole moment of the muon
No full textThe electric dipole moments~(EDM) of fundamental particles inherently violate parity~(P) and time-reversal~(T) symmetries. By virtue of the CPT theorem in quantum field theory, the latter also implies the violation of the combined charge-conjugation and parity~(CP) symmetry. We aim to measure the EDM of the muon using the frozen-spin technique within a compact storage trap. This method exploits the high effective electric field, MV/m, experienced in the rest frame of the muon with a momentum of about 23 MeV/c when it passes through a solenoidal magnetic field of T. In this paper, we outline the fundamental considerations for a muon EDM search and present a conceptual design for a demonstration experiment to be conducted at secondary muon beamlines of the Paul Scherrer Institute in Switzerland. In Phase~I, with an anticipated data acquisition period of 200 days, the expected sensitivity to a muon EDM is 4E-21 ecm. In a subsequent phase, Phase~II, we propose to improve the sensitivity to 6E-23 ecm using a dedicated instrument installed on a different beamline that produces muons of momentum 125 MeV/c
