The ATLAS experiment at the CERN Large Hadron Collider: a description of the detector configuration for Run 3

The ATLAS detector is installed in its experimental cavern at Point 1 of the CERN Large Hadron Collider. During Run 2 of the LHC, a luminosity of ℒ = 2 × 1034 cm-2 s-1 was routinely achieved at the start of fills, twice the design luminosity. For Run 3, accelerator improvements, notably luminosity levelling, allow sustained running at an instantaneous luminosity of ℒ = 2 × 1034 cm-2 s-1, with an average of up to 60 interactions per bunch crossing. The ATLAS detector has been upgraded to recover Run 1 single-lepton trigger thresholds while operating comfortably under Run 3 sustained pileup conditions. A fourth pixel layer 3.3 cm from the beam axis was added before Run 2 to improve vertex reconstruction and b-tagging performance. New Liquid Argon Calorimeter digital trigger electronics, with corresponding upgrades to the Trigger and Data Acquisition system, take advantage of a factor of 10 finer granularity to improve triggering on electrons, photons, taus, and hadronic signatures through increased pileup rejection. The inner muon endcap wheels were replaced by New Small Wheels with Micromegas and small-strip Thin Gap Chamber detectors, providing both precision tracking and Level-1 Muon trigger functionality. Trigger coverage of the inner barrel muon layer near one endcap region was augmented with modules integrating new thin-gap resistive plate chambers and smaller-diameter drift-tube chambers. Tile Calorimeter scintillation counters were added to improve electron energy resolution and background rejection. Upgrades to Minimum Bias Trigger Scintillators and Forward Detectors improve luminosity monitoring and enable total proton-proton cross section, diffractive physics, and heavy ion measurements. These upgrades are all compatible with operation in the much harsher environment anticipated after the High-Luminosity upgrade of the LHC and are the first steps towards preparing ATLAS for the High-Luminosity upgrade of the LHC. This paper describes the Run 3 configuration of the ATLAS detector

Ferrite characterization techniques & particle simulations for semiconductor devices

This dissertation is divided into three papers, covering two major topics. The first topic, techniques for ferrite characterization, is discussed over the course of two papers. The second topic, particle simulations for semiconductor devices, is discussed in the last paper. In the first paper, the method for extracting permeability from ferrite materials is discussed for the Keysight 16454A permeability extraction fixture, where the ferrite material to be characterized is assumed to be homogeneous. Then the method is updated to account for layered materials. The updated method is verified through full-wave simulations. In the second paper, a planar printed circuit board (PCB) coil is proposed as an alternative to the Keysight 16454A fixture for extracting permeability from ferrite materials. The method of extraction is verified through full-wave simulations. The final paper (and second topic) develops a particle simulator, based on the Boltzmann transport equation (BTE) and Monte Carlo (MC) methods, for studying semiconductor devices with submicron feature sizes. Particle simulations are advantageous because full-wave simulators based purely on Maxwell\u27s equations are not able to capture certain semiconductor effects. This work specifically investigates metal-oxide-semiconductor (MOS) effects for a pair of through-silicon-vias (TSVs), and the corresponding accumulation and depletion regions formed for different bias voltages --Abstract, page iv

The IceCube Neutrino Observatory: Instrumentation and Online Systems

The IceCube Neutrino Observatory is a cubic-kilometer-scale high-energy neutrino detector built into the ice at the South Pole. Construction of IceCube, the largest neutrino detector built to date, was completed in 2011 and enabled the discovery of high-energy astrophysical neutrinos. We describe here the design, production, and calibration of the IceCube digital optical module (DOM), the cable systems, computing hardware, and our methodology for drilling and deployment. We also describe the online triggering and data filtering systems that select candidate neutrino and cosmic ray events for analysis. Due to a rigorous pre-deployment protocol, 98.4% of the DOMs in the deep ice are operating and collecting data. IceCube routinely achieves a detector uptime of 99% by emphasizing software stability and monitoring. Detector operations have been stable since construction was completed, and the detector is expected to operate at least until the end of the next decade.Comment: 83 pages, 50 figures; updated with minor changes from journal review and proofin

Topical Workshop on Electronics for Particle Physics

The purpose of the workshop was to present results and original concepts for electronics research and development relevant to particle physics experiments as well as accelerator and beam instrumentation at future facilities; to review the status of electronics for the LHC experiments; to identify and encourage common efforts for the development of electronics; and to promote information exchange and collaboration in the relevant engineering and physics communities

Mu2e Technical Design Report

The Mu2e experiment at Fermilab will search for charged lepton flavor violation via the coherent conversion process mu- N --> e- N with a sensitivity approximately four orders of magnitude better than the current world's best limits for this process. The experiment's sensitivity offers discovery potential over a wide array of new physics models and probes mass scales well beyond the reach of the LHC. We describe herein the preliminary design of the proposed Mu2e experiment. This document was created in partial fulfillment of the requirements necessary to obtain DOE CD-2 approval.Comment: compressed file, 888 pages, 621 figures, 126 tables; full resolution available at http://mu2e.fnal.gov; corrected typo in background summary, Table 3.

The Fast Track Trigger Upgrade for the ATLAS Experiment High Rate Trigger Algorithms

At LHC, in the context of the ATLAS experiment, for the so-called Phase-II, the instantaneous luminosity is expected to reach $5\cdot 10^{34} cm^{-2} s^{-1}$. In such conditions the overlapping collisions and the QCD multi-jet production makes triggering on heavy fermions (such as $b$ quarks and $\tau$ leptons) an extremely difficult challenge. The standard methods used at offline levels to select these objects such as $b$-tagging and primary vertex reconstruction require full granularity information from the tracker of the ATLAS detector and are therefore too time consuming to be implemented at trigger level. Within the ATLAS experiment, the FTK project has developed a custom processor that is capable of reconstructing all the tracks within an event after the Level-1 trigger. In fact FTK can provide real time tracking at 100 kHz using a highly parallelized and high performance system. In my thesis I will describe the FTK system in detail, in the context of the the ATLAS experiment itself. I will also summarize the FTK performances showing that the early availability of reconstructed tracks immediately after the Level-1 increases the signal efficiency while maintaining the same background rate. I will also describe my work on the development of modules that allow to monitor and test the digital logic of the Associative Memory (AM) Board, the core of the FTK processing unit. The AM board in fact, is equipped with custom memory chips (AM chips) capable of ultra-parallized pattern matching. The memories receive the hit information from the tracker they give in output coarse reconstructed tracks that make the fast high quality track fitting, done by the FTK processing unit, possible. Once the FTK system will be fully functional the High Level Trigger performance will be highly improved and it becomes important to optimize the Level-1 trigger to be able to profit at best of the improved trigger performance. For this reason a new approach on Level-1 selection of purely hadronic decays of the Higgs boson will be described in the second part of the thesis. The new strategies rely on global features of the event and not only in single thresholds. The Randall-Sundrum Graviton with a mass of 500 GeV and decaying to a couple of Standard Model Higgs each one decaying to $b\bar{b}$ has been used as benchmark signal. The trigger algorithms developed follow two major strategies: the tagging of calorimetric clusters at Level-1 with muons from the semileptonic decay of the $b$ quark, done trough the exploitation of the newly installed topological trigger, and the selection based on clean multi-jet topological and kinematic configuration. Efficiencies on signal selection and background selection are calculated for both selection algorithms