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1. Acceptance Tests of more than 10 000 Photomultiplier Tubes for the multi-PMT Digital Optical Modules of the IceCube Upgrade

   https://doi.org/10.1088/1748-0221/19/07/P07038  

   Abbasi, R; Ackermann, M; Adams, J; Agarwalla, SK; Aguilar, JA; Ahlers, M; Alameddine, JM; Amin, NM; Andeen, K; Anton, G; et al (July 2024, Journal of Instrumentation)

   IceCube_Collaboration (Ed.)

   Abstract More than 10000 photomultiplier tubes (PMTs) with a diameter of 80 mm will be installed in multi-PMT Digital Optical Modules (mDOMs) of the IceCube Upgrade. These have been tested and pre-calibrated at two sites. A throughput of more than 1000 PMTs per week with both sites was achieved with a modular design of the testing facilities and highly automated testing procedures. The testing facilities can easily be adapted to other PMTs, such that they can, e.g., be re-used for testing the PMTs for IceCube-Gen2. Single photoelectron response, high voltage dependence, time resolution, prepulse, late pulse, afterpulse probabilities, and dark rates were measured for each PMT. We describe the design of the testing facilities, the testing procedures, and the results of the acceptance tests. 

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2. D-Egg: a dual PMT optical module for IceCube

   https://doi.org/10.1088/1748-0221/18/04/P04014  

   Abbasi, R.; Ackermann, M.; Adams, J.; Aggarwal, N.; Aguilar, J.A.; Ahlers, M.; Alameddine, J.M.; Alves, A.A.; Amin, N.M.; Andeen, K.; et al (April 2023, Journal of Instrumentation)

   Abstract The D-Egg, an acronym for “Dual optical sensors in an Ellipsoid Glass for Gen2,” is one of the optical modules designed for future extensions of the IceCube experiment at the South Pole. The D-Egg has an elongated-sphere shape to maximize the photon-sensitive effective area while maintaining a narrow diameter to reduce the cost and the time needed for drilling of the deployment holes in the glacial ice for the optical modules at depths up to 2700 m. The D-Egg design is utilized for the IceCube Upgrade, the next stage of the IceCube project also known as IceCube-Gen2 Phase 1, where nearly half of the optical sensors to be deployed are D-Eggs. With two 8-inch high-quantum efficiency photomultiplier tubes (PMTs) per module, D-Eggs offer an increased effective area while retaining the successful design of the IceCube digital optical module (DOM). The convolution of the wavelength-dependent effective area and the Cherenkov emission spectrum provides an effective photodetection sensitivity that is 2.8 times larger than that of IceCube DOMs. The signal of each of the two PMTs is digitized using ultra-low-power 14-bit analog-to-digital converters with a sampling frequency of 240 MSPS, enabling a flexible event triggering, as well as seamless and lossless event recording of single-photon signals to multi-photons exceeding 200 photoelectrons within 10 ns. Mass production of D-Eggs has been completed, with 277 out of the 310 D-Eggs produced to be used in the IceCube Upgrade. In this paper, we report the design of the D-Eggs, as well as the sensitivity and the single to multi-photon detection performance of mass-produced D-Eggs measured in a laboratory using the built-in data acquisition system in each D-Egg optical sensor module. 

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3. Physics Potential of a Radio Surface Array at the South Pole

   https://doi.org/10.1051/epjconf/201921601007  

   Schröder, Frank G.; Riccobene, G.; Biagi, S.; Capone, A.; Distefano, C.; Piattelli, P. (January 2019, EPJ Web of Conferences)

   A surface array of radio antennas will enhance the performance of the IceTop array and enable new, complementary science goals. First, the accuracy for cosmic-ray air showers will be increased since the radio array provides a calorimetric measurement of the electromagnetic component and is sensitive to the position of the shower maximum. This enhanced accuracy can be used to better measure the mass composition, to search for possible mass-dependent anisotropies in the arrival directions of cosmic rays, and for more thorough tests of hadronic interaction models. Second, the sensitivity of the radio array to inclined showers will increase the sky coverage for cosmic-ray measurements. Third, the radio array can be used to search for PeV photons from the Galactic Center. Since IceTop is planned to be enhanced by a scintillator array in the near future, a radio extension sharing the same infrastructure can be installed with minimal additional effort and excellent scientific prospects. The combination of ice-Cherenkov, scintillation, and radio detectors at IceCube will provide unprecedented accuracy for the study of highenergy Galactic cosmic rays. 

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4. A Universal In-Place Reconfiguration Algorithm for Sliding Cube-Shaped Robots in a Quadratic Number of Moves

   https://doi.org/10.4230/LIPIcs.SoCG.2024.1  

   Abel, Zachary; A_Akitaya, Hugo; Kominers, Scott Duke; Korman, Matias; Stock, Frederick (January 2024, Schloss Dagstuhl – Leibniz-Zentrum für Informatik)

   Mulzer, Wolfgang; Phillips, Jeff M (Ed.)

   In the modular robot reconfiguration problem, we are given n cube-shaped modules (or robots) as well as two configurations, i.e., placements of the n modules so that their union is face-connected. The goal is to find a sequence of moves that reconfigures the modules from one configuration to the other using "sliding moves," in which a module slides over the face or edge of a neighboring module, maintaining connectivity of the configuration at all times. For many years it has been known that certain module configurations in this model require at least Ω(n²) moves to reconfigure between them. In this paper, we introduce the first universal reconfiguration algorithm - i.e., we show that any n-module configuration can reconfigure itself into any specified n-module configuration using just sliding moves. Our algorithm achieves reconfiguration in O(n²) moves, making it asymptotically tight. We also present a variation that reconfigures in-place, it ensures that throughout the reconfiguration process, all modules, except for one, will be contained in the union of the bounding boxes of the start and end configuration. 

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5. Material Use and Life Cycle Impact of Crystalline Silicon PV Modules Over Time

   https://doi.org/10.1109/PVSC48317.2022.9938923  

   Yuan, Luyao; Anctil, Annick (January 2022, 2022 IEEE 49th Photovoltaics Specialists Conference (PVSC))

   Most life cycle assessment (LCA) of crystalline silicon photovoltaics (c-Si PV) modules are based on public life cycle inventory (LCI) datasets with limited use of actual manufacturing data. We collect and calculate the amount of material used for production of different PV modules installed in the U.S. to analyze the trend in material intensity over and compare the numbers among various tier manufacturers and module reliability. Furthermore, results of LCA models using the public LCI data and the actual manufacturing material (specifically aluminum) data are compared to investigate the impact of material use on the life-cycle impact assessment of c-Si PV modules. Results show a trend of material use decrease over time and indicate a potential connection between material usage and the manufacturer tier – better manufacturers tend to use more materials for modules production which may lead to higher quality performance. Additional work will complete the life cycle assessment, explore more materials, and fill the data gap of PV modules produced by different manufacturer tiers in different years. 

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