Transferring Electron Beam Welding Parameters Between DIfferent Machines and Facilities Using Advanced Diagnostics

Transferring electron beam (EB) welding parameters between different welders can be a costly and time consuming process requiring the completion of expensive weld parameter studies. In order to modernize and streamline this process, the LLNL Beam Profiler diagnostic tool, which has been developed and tested at Lawrence Livermore National Laboratory (LLNL) to measure the size, shape, and power density distribution of electron beams, is currently being used to characterize the performance of EB machines at several U.S. Department of Energy facilities. The characterization of these machines involves performing defocus studies on each welder to measure the properties of 1 kW beams made at constant current, voltage, and work distance settings. Using these carefully characterized beams, autogenous welds on 304L stainless steel were then made at LLNL and replicated on the other machines. A key finding from these studies was that the widespread use of work distance values measured from the surface of the part being welded to the top of the EB vacuum chamber are suitable only for machines with a similar upper column design. Otherwise, the focus-lens to part distance must be determined and controlled. A simple method for determining the focus-lens to part distance with the LLNL Beam Profiler diagnostic tool is presented. The ability to transfer EB welds between machines represents a major accomplishment in the development and more widespread use of this diagnostic tool. This work also serves as a basis for the continuing development of procedures and equipment for characterizing electron beams and as a precursor to the development of a modern weld transfer procedure

Performance of a modular ton-scale pixel-readout liquid argon time projection chamber

The Module-0 Demonstrator is a single-phase 600 kg liquid argon time projection chamber operated as a prototype for the DUNE liquid argon near detector. Based on the ArgonCube design concept, Module-0 features a novel 80k-channel pixelated charge readout and advanced high-coverage photon detection system. In this paper, we present an analysis of an eight-day data set consisting of 25 million cosmic ray events collected in the spring of 2021. We use this sample to demonstrate the imaging performance of the charge and light readout systems as well as the signal correlations between the two. We also report argon purity and detector uniformity measurements and provide comparisons to detector simulations

The DUNE far detector vertical drift technology. Technical design report

DUNE is an international experiment dedicated to addressing some of the questions at the forefront of particle physics and astrophysics, including the mystifying preponderance of matter over antimatter in the early universe. The dual-site experiment will employ an intense neutrino beam focused on a near and a far detector as it aims to determine the neutrino mass hierarchy and to make high-precision measurements of the PMNS matrix parameters, including the CP-violating phase. It will also stand ready to observe supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector implements liquid argon time-projection chamber (LArTPC) technology, and combines the many tens-of-kiloton fiducial mass necessary for rare event searches with the sub-centimeter spatial resolution required to image those events with high precision. The addition of a photon detection system enhances physics capabilities for all DUNE physics drivers and opens prospects for further physics explorations. Given its size, the far detector will be implemented as a set of modules, with LArTPC designs that differ from one another as newer technologies arise. In the vertical drift LArTPC design, a horizontal cathode bisects the detector, creating two stacked drift volumes in which ionization charges drift towards anodes at either the top or bottom. The anodes are composed of perforated PCB layers with conductive strips, enabling reconstruction in 3D. Light-trap-style photon detection modules are placed both on the cryostat's side walls and on the central cathode where they are optically powered. This Technical Design Report describes in detail the technical implementations of each subsystem of this LArTPC that, together with the other far detector modules and the near detector, will enable DUNE to achieve its physics goals

Effect of osmotic dehydration as pretreatment in the preparation of appllet jelly.

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