The ATLAS central solenoid magnet is being constructed to provide a magnetic field of 2 T in the central tracking part of the ATLAS detector. As a key technology for a solenoid coil as thin as possible, a high-strength aluminum stabilized superconductor has been developed, achieving a yield strength of >100 MPa at 4.2 K. This paper describes the status of the design and development of the solenoid magnet.

Oxford Instruments took over the manufacture of the 5.7 m outer diameter 4.5 m long 0.6 T Solenoid for the KLOE detector on the DAPHNE ring when the Austrian company ELIN closed its magnet manufacturing plant. The paper begins by discussing the magnet design before going on to describe the approach Oxford has taken to the completion of the magnet. The status of the system will be described along with the proposed completion schedule.

Within the LHC magnet development program Oxford Instruments has built a one metre model of the 70 mm aperture low-/spl beta/ quadrupole. The magnet features a four layer coil wound from two 8.2 mm wide graded NbTi cables, and is designed for 250 T/m at 1.9 K. The magnet has previously been tested between 4.5 K and 23 K. In this paper we review the magnet rebuild and the subsequent tests. Results on magnet training at 43 K and 1.9 K are presented along with the results related to quench protection studies. We also present the first results of magnetic field measurements done at room and liquid nitrogen temperatures.

of Texas at Austin (UT-Austin) that is endeavoring to reveal novel physical phenomena through the discovery of new particles with the ATLAS detector at the LHC. A key element of our experience thus far has been collaborating closely with theorists to identify both interesting new physics models. In addition we work closely with electrical engineers in detector development. Our approach is therefore unique in its integration of theory, analysis and instrumentation, and is encapsulated in a three-pronged strategy. First is the essential task of analyzing our rapidly expanding dataset. I am directing my group in searches for vector-like quarks (VLQs). Should they exist, these hypothetical particles would indicate physics scenarios beyond the SM. Experimental constraints suggest VLQs decay preferentially to a third generation quark and a Higgs, W or Z boson. Today at 13 TeV, both multi-lepton (electron and muon) and jet substructure signatures are sensitive to identifying the VLQ decay products. The large Run 2 dataset (collected through 2018) of up to 150 fb-1 will allow us to simultaneously use multi-lepton signatures with jet-substructure in searches for new physics. UT-Austin is well positioned to be a leader in this area. Prof. P. Onyisi’s postdoctoral researchers and graduate students are searching for ttH signatures in three- and four-lepton channels and we benefit from their experience. We are also aided by the availability of the Texas Advanced Computing Center, which provides us with easy access to several high performance computing (HPC) systems. My previous experience in VLQ searches propels the work today. I have published both the first investigation into the single production of top partners (signatures of composite Higgs Models) of any LHC experiment 1 as well as one of the first analyses utilizing jet-substructure techniques to search for the single production of vector-like quarks. 2 Adding to this is my group’s work with the Liquid Argon (LAr) calorimeter, the primary instrument we use in detecting electrons. Second, my group is contributing to the operations of the LAr calorimeter while preparing to install and commission new electronic hardware (the Phase 1 upgrade) to this crucial component of the ATLAS detector. I have played a leading role in the development of a critical, radiation-hard, high-speed Analog-to-Digital Convertor (ADC) that is essential inselecting data collected by the LAr calorimeter. 3 This upgrade will improve the e!ciency with which we can select events in our detector. Postdoctoral researcher N. Nikiforou (based at CERN May 2016 onward) and graduate students (one based at CERN from the start of 2018 onward, with one additional graduate students from summer 2018) are growing our already deep experience in the operation of the LAr calorimeter to prepare for installation and commissioning of the new trigger readout in 2018-2019. My group will then be positioned to be the first to exploit the potential of the improved triggers in our multi-lepton searches for new physics. Third, a suite of preparations for a major detector upgrade, scheduled to be completed in 2024, are underway. My group is building hardware that will improve the electronic readout of the ATLAS detector. I am partnering with a group in the Electrical and Computer Engineering (ECE) Department at UT-Austin (Prof. N. Sun) to employ his work at the cutting edge of ADC research. We will support an ECE grad student for the layout of this design, and collaborate with engineering groups at Nevis Laboratory and the Electrical Engineering Department (Prof. P. Kinget) at Columbia University to integrate our ADC with gain selection circuits. We will provide this critical component of the ASIC at the challenging boundary of the analog and digital signals in the LAr calorimeter readout chain. Furthermore UT-Austin will lead the testing of this device during development and production (approximately 55,000 four-channel chips). This effort compliments my work as the deliverables manager for the LAr front-end ASICs for the US ATLAS HL-LHC project and strengthens the US commitment to that upgrade.In so doing, my group at the UT-Austin will be at the forefront of efforts to probe the structure of the universe to an unmatched degree both at the current LHC and with its future upgrades. Through both the ongoing analysis of data at the ATLAS detector and improvements to the detector itself, an answer to what lies beyond the SM may come within our grasp. My background in instrumentation and analysis allows my group to establish a singular research effort on the ATLAS experiment. In addition to answering fundamental questions about the subatomic world, the technologies developed could advance the broader scientific community and result in valuable spin-offs.

Different potential types of insulation for the ITER conductor were investigated with emphasis on testing new materials and those materials not already thoroughly investigated at cryogenic temperatures, which research has shown may be practical. Candidate materials must survive prolonged irradiation, simultaneous high compressive and shear stresses, and have high electrical reliability. The materials chosen are intended to meet the demands of full-scale coil manufacture. Although the current programme does not include irradiation testing, only materials believed to withstand high radiation doses have been selected.

The 6-T wiggler is an iron-cored, warm bore, superconducting dipole magnet destined for the SERC Daresbury (UK) Laboratory's 2-GeV synchrotron radiation source to enhance the available radiation spectrum. The authors describe the major features of the magnet and include a discussion of detailed magnetic and cryogenic tests. The magnet provides a peak field of 6 T on the beam line, which was reached after four training quenches. The design and manufacturing contract for this magnet was started in September 1989 and was preceded by a feasibility study, presented in mid-1988. At the end of the feasibility study the recommendation was for a design incorporating a room temperature beam pipe and soft magnetic iron pole pieces. The magnet was cooled and successfully tested at Daresbury in February 1992. The ease with which reliable operation at 6 T was obtained and the good comparison between predicted and measured magnetic fields were results arising from the works tests.<>

Following the successful testing of the first 1-metre model of the 70 mm aperture quadrupole for the LHC low- insertions, two further 1-metre magnets have been built. All magnets feature a four-layer coil wound from two 8.2 mm wide graded NbTi cables and a four-way split yoke supporting structure. In this paper we review the training history of the three magnets performed at 4.3 K and 1.9 K in several tests. All magnets surpassed the operating gradient required for the LHC, with the third magnet reaching 260 T/m, its short-sample gradient at 1.9 K. The peak temperatures in the superconductor at various operating conditions are reported and a summary of magnetic field measurements is given.