R. French

The evaporative cooling system for the ATLAS inner detector

This paper describes the evaporative system used to cool the silicon detector structures of the inner detector sub-detectors of the ATLAS experiment at the CERN Large Hadron Collider. The motivation for an evaporative system, its design and construction are discussed. In detail the particular requirements of the ATLAS inner detector, technical choices and the qualification and manufacture of final components are addressed. Finally results of initial operational tests are reported. Although the entire system described, the paper focuses on the on-detector aspects. Details of the evaporative cooling plant will be discussed elsewhere.

A double-sided, shield-less stave prototype for the ATLAS Upgrade strip tracker for the High Luminosity LHC

A detailed description of the integration structures for the barrel region of the silicon strips tracker of the ATLAS Phase-II upgrade for the upgrade of the Large Hadron Collider, the so-called High Luminosity LHC (HL-LHC), is presented. This paper focuses on one of the latest demonstrator prototypes recently assembled, with numerous unique features. It consists of a shortened, shield-less, and double sided stave, with two candidate power distributions implemented. Thermal and electrical performances of the prototype are presented, as well as a description of the assembly procedures and tools.

Scanning facility to irradiate mechanical structures for the LHC upgrade programme

The existing luminosity of the LHC will be increased in stages to a factor of 10 above its current level (HL-LHC) by 2022. This planned increase in luminosity results in significantly higher levels of radiation inside the proposed ATLAS Upgrade detector. This means existing detector technologies together with new components and materials need to be re-examined to evaluate their performance and durability at these higher fluences. Of particular interest is the effect of radiation on the upgraded ATLAS tracker. To study these effects a new ATLAS irradiation scanning facility has been developed using the Medical Physics Cyclotron at the University of Birmingham. The intense cyclotron beams allow irradiated samples to receive in minutes fluences corresponding to years of operation at the HL-LHC. Since commissioning in early 2013, this facility has been used to irradiate silicon sensors, optical components and carbon fibre sandwiches for the ATLAS upgrade programme. Irradiations of silicon sensors and passive materials can be carried out in a temperature controlled cold box which moves continuously through the homogenous beamspot. This movement is provided by a pre-configured XY-axis cartesian robot system (scanning system). This paper reviews the design, development, commissioning, performance results and future plans of the irradiation facility, fully operational since 2013.

A double-sided silicon micro-strip Super-Module for the ATLAS Inner Detector upgrade in the High-Luminosity LHC

The ATLAS experiment is a general purpose detector aiming to fully exploit the discovery potential of the Large Hadron Collider (LHC) at CERN. It is foreseen that after several years of successful data-taking, the LHC physics programme will be extended in the so-called High-Luminosity LHC, where the instantaneous luminosity will be increased up to 5 × 1034 cm−2 s−1. For ATLAS, an upgrade scenario will imply the complete replacement of its internal tracker, as the existing detector will not provide the required performance due to the cumulated radiation damage and the increase in the detector occupancy. The current baseline layout for the new ATLAS tracker is an all-silicon-based detector, with pixel sensors in the inner layers and silicon micro-strip detectors at intermediate and outer radii. The super-module is an integration concept proposed for the strip region of the future ATLAS tracker, where double-sided stereo silicon micro-strip modules are assembled into a low-mass local support structure. An electrical super-module prototype for eight double-sided strip modules has been constructed. The aim is to exercise the multi-module readout chain and to investigate the noise performance of such a system. In this paper, the main components of the current super-module prototype are described and its electrical performance is presented in detail.

High Value Intelligent Aerospace Turbofan Jet Engine Blade Re-manufacturing System

Development of any advanced, intelligent robotic welding system requires correct interrogation of welding parameters and output. Advanced programming of robots, data interpretation from associated sensory and feedback systems are required to mirror human input. Using process analysis to determine stimuli, replacement of human sensory receptors with electronic sensors, vision systems and high speed data acquisition and control systems allows for the intelligent fine tuning of multiple welding parameters at any one time. This paper demonstrates the design process, highlighting interaction between robotics and experienced welding engineers, towards construction of an autonomous aerospace turbofan jet engine blade re-manufacturing system. This is a joint collaborative research and development project carried out by VBC Instrument Engineering Ltd (UK) and The University of Sheffield (UK) who are funded by the UK governments’ innovation agency, Innovate-UK and the Aerospace Technology Institute (UK).

A Robotic Re-manufacturing System for High-Value Aerospace Repair and Overhaul

This paper describes the necessary elements for the development of a bespoke robotic welding system for aerospace turbofan compressor blade re-manufacturing. The established industry-academia research partnership and project evolution at The University of Sheffield (UK) from 2006 is highlighted in the joint development of a disruptive platform technology for high-value aerospace re-manufacturing. The design process, funding mechanisms, research and development of key components (vision system, high-speed DAQ, advanced GTAW welding system trials) are described in this paper. Interaction of these key components when combined with novel collaborative robotic technology and experienced welding engineers has made this project possible. This industry-academia research intensive collaboration between VBC Instrument Engineering Limited (UK) and The University of Sheffield has received project funding from the Engineering and Physical Sciences Research Council (EPSRC, 2006–2010), the Science and Facilities Technology Council (STFC, 2011–2013) and Innovate-UK with the Aerospace Technology Institute (2014–2018).

Advanced Real-Time Weld Monitoring Evaluation Demonstrated with Comparisons of Manual and Robotic TIG Welding Used in Critical Nuclear Industry Fabrication

Ensuring critical welded joint quality and repeatability is largely dependent on robust, well-designed Welding Procedure Specifications (WPS). Highly skilled manual welding engineers automatically recognise many imperfections, adjusting their responses according to inputs from vision, smell and sounds made during the welding process. Unfortunately, exceptional human ability does not guarantee performance when less predictable influences occur during welding processes. Human error and materials imperfections can result in defective welds for critical applications, commonly attributed to material surface impurities and contamination. Fault detection is problematic; the only finite method of weld testing is destructive testing which is not applicable to final product verification. Quality assurance and control is used to guarantee the welding process repeatability by production of a Procedure Qualification Record. This often-lengthy approval process restricts welding technology and materials application advancement. An alternative method of testing is the detection of flaws and defects in real-time to allow immediate process corrections. Development of real time welding evaluation instrumentation requires welding process parameters measurements combined with high-speed data processing. This real time monitoring and evaluation produces a weld defect fingerprint used to determine quality. We aim to highlight variations found in welding process quality using real-time monitoring and assess if it is within the acceptable standards for nuclear applications. To achieve this, we first must understand the human welding engineer using data taken from a series of manual weld trials. The trials use a common welding operation found in nuclear reactor pressure vessels. Reference data comparisons are made using identical trials with robotic welding equipment. Trial comparison results indicate that real time evaluation of welding processes detects flaws in weld quality. We then demonstrate how applications of welding process parameters are exceptionally effective methods for the control of robotic welding applications.

Usability study to qualify a dexterous robotic manipulator for high radiation environments

Based at CERN, the European Organization for Nuclear Research, the Large Hadron Collider (LHC) is the worlds largest and most powerful particle accelerator. From 2025, the LHC will be upgraded to allow it to achieve a factor of 10 higher luminosity, which increases the rate of collisions, essential for probing new physics phenomena in the future. The route to high luminosity LHC (HL-LHC) involves various detector upgrades and requires significant infrastructure changes. Recent measurements by CERN Radiation Protection, verifying previous calculations by The University of Sheffield (UoS), has raised awareness about the need to restrict human activity in the HL-LHC experimental, construction and maintenance areas due to exposure from high levels of radiation. Examining the case of the ATLAS detector upgrade, the collaborative partnership between UoS and UK industry is developing state-of-the-art robotic instrumentation, capable of tolerating high radiation levels. The main object of this research is a feasibility study with a TRL (technology readiness level) of three, to determine how materials and sub components of dexterous robotic systems behave after exposure to high levels of radiation. This is evaluation uses novel robotic irradiation equipment, techniques and test methods housed in the Birmingham University (UK) Irradiation Facility. One finger of an unmodified Shadow Robot Company “Hand”, a highly dexterous robotic manipulator, was exposed to specific doses of high radiation in a temperature controlled thermal chamber. Cooled by a liquid nitrogen evaporative system, the irradiation system moves samples continuously through a homogeneous proton beam. Movement is provided by a radiation hard pre-configured XY-Axis Cartesian Robot. The methods and techniques developed as a result of this TRL3 research will further aid the application and deployment of robotic and autonomous systems into highly radioactive environments. Based on preliminary findings it has been concluded that finger materials and basic electrical components can tolerate hazardous radiation environments, with careful selection and substitution of a minimal amount of materials, radiation hardness is also possible. Further work is scheduled for the irradiation of a fully instrumented and powered robotic hand to determine working hour tolerance.

Evaluating the Radiation Tolerance of a Robotic Finger

In 2024, The Large Hadron Collider (LHC) at CERN will be upgraded to increase its luminosity by a factor of 10 (HL-LHC). The ATLAS inner detector (ITk) will be upgraded at the same time. It has suffered the most radiation damage, as it is the section closest to the beamline, and the particle collisions. Due to the risk of excessive radiation doses, human intervention to decommission the inner detector will be restricted. Robotic systems are being developed to carry out the decommissioning and limit radiation exposure to personnel. In this paper, we present a study of the radiation tolerance of a robotic finger assessed in the Birmingham Cyclotron facility. The finger was part of the Shadow Grasper from Shadow Robot Company, which uses a set of Maxon DC motors.

Transfer Analysis of Human Engineering Skills for Adaptive Robotic Additive Manufacturing in the Aerospace Repair and Overhaul Industry

The desire for smart “lights out factories” which can autonomously produce components for high value manufacturing industries is described by the Industry 4.0 solution. This manufacturing methodology is appropriate for newly designed components, which take advantage of modern materials, robotic and automation processes, but not necessarily applicable to overhaul and repair. The aerospace overhaul and repair industry remains heavily dependent on human engineering skills to develop repair and re-manufacturing techniques for complex components of high value.