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  1. ; ; ; ; ; ; ; ; ; ; et al ( , Computersupported collaborative learning)
    Weinberger, A. ; Chen, W. ; Hernández-Leo, D. ; & Chen, B. (Ed.)
    SimSnap responds to the need for a technology-based tool that supports learning at three social planes—individual, small group, and whole-class—while being easy to deploy with minimal technology overhead costs during their uptake. While much research has examined the efficacy of large-scale collaborative systems and individual-oriented learning systems, the intersection of and the movement between the three social planes is under explored. SimSnap is a cross-device, tablet-based platform that facilitates learning science concepts for middle school students through interactive simulations. Students in physical proximity can ‘snap’ their devices together to collaborate on learning activities. SimSnap enables real-time transition between individual andmore »group activities in a classroom by offering reconfigurable simulations. SimSnap also provides an environment where open-ended and task-specific learning trajectories can be explored to maximize students’ learning potential. In this iteration of SimSnap, we have designed and implemented our first curriculum on SimSnap, focusing on plant biology, ecosystems, and genetics.« less
    Free, publicly-accessible full text available June 1, 2023
  2. ; ; ; ; ; ; ; ; ; ; et al ( , The Astrophysical Journal)
    Abstract We report on the design and performance of the B icep3 instrument and its first three-year data set collected from 2016 to 2018. B icep3 is a 52 cm aperture refracting telescope designed to observe the polarization of the cosmic microwave background (CMB) on degree angular scales at 95 GHz. It started science observation at the South Pole in 2016 with 2400 antenna-coupled transition-edge sensor bolometers. The receiver first demonstrated new technologies such as large-diameter alumina optics, Zotefoam infrared filters, and flux-activated SQUIDs, allowing ∼10× higher optical throughput compared to the Keck design. B icep3 achieved instrument noise equivalentmore »temperatures of 9.2, 6.8, and 7.1 μ K CMB s and reached Stokes Q and U map depths of 5.9, 4.4, and 4.4 μ K arcmin in 2016, 2017, and 2018, respectively. The combined three-year data set achieved a polarization map depth of 2.8 μ K arcmin over an effective area of 585 square degrees, which is the deepest CMB polarization map made to date at 95 GHz.« less
    Free, publicly-accessible full text available March 1, 2023
  3. ; ; ; ; ; ; ; ; ; ; et al ( , 2022 Cosmology session of the 56th Rencontres de Moriond)
    For the past decade, the BICEP/Keck collaboration has been operating a series of telescopes at the Amundsen-Scott South Pole Station measuring degree-scale B-mode polarization imprinted in the Cosmic Microwave Background (CMB) by primordial gravitational waves (PGWs). These telescopes are compact refracting polarimeters mapping about 2% of the sky, observing at a broad range of frequencies to account for the polarized foreground from Galactic synchrotron and thermal dust emission. Our latest publication "BK18" utilizes the data collected up to the 2018 observing season, in conjunction with the publicly available WMAP and Planck data, to constrain the tensor-to-scalar ratio r. It particularlymore »includes (1) the 3-year BICEP3 data which is the current deepest CMB polarization map at the foreground-minimum 95 GHz; and (2) the Keck 220 GHz map with a higher signal-to-noise ratio on the dust foreground than the Planck 353 GHz map. We fit the auto- and cross-spectra of these maps to a multicomponent likelihood model (ΛCDM+dust+synchrotron+noise+r) and find it to be an adequate description of the data at the current noise level. The likelihood analysis yields σ(r)=0.009. The inference of r from our baseline model is tightened to r0.05=0.014+0.010−0.011 and r0.05<0.036 at 95% confidence, meaning that the BICEP/Keck B-mode data is the most powerful existing dataset for the constraint of PGWs. The up-coming BICEP Array telescope is projected to reach σ(r)≲0.003 using data up to 2027.« less
    Free, publicly-accessible full text available March 1, 2023
  4. ; ; ; ; ; ; ; ; ; ; et al ( , Journal of low temperature physics)
    The BICEP/Keck Collaboration is currently leading the quest to the highest sensitivity measurements of the polarized CMB anisotropies on degree scale with a series of cryogenic telescopes, of which BICEP Array is the latest Stage-3 upgrade with a total of ∼32,000 detectors. The instrument comprises 4 receivers spanning 30 to 270 GHz, with the low-frequency 30/40 GHz deployed to the South Pole Station in late 2019. The full complement of receivers is forecast to set the most stringent constraints on the tensor to scalar ratio r. Building on these advances, the overarching small-aperture telescope concept is already being used asmore »the reference for further Stage-4 experiment design. In this paper I will present the development of the BICEP Array 150 GHz detector module and its fabrication requirements, with highlights on the high-density time division multiplexing (TDM) design of the cryogenic circuit boards. The low-impedance wiring required between the detectors and the first-stage SQUID amplifiers is crucial to maintain a stiff voltage bias on the detectors. A novel multi-layer FR4 Printed Circuit Board (PCB) with superconducting traces, capable of reading out up to 648 detectors, is presented along with its validation tests. I will also describe an ultra-high density TDM detector module we developed for a CMB-S4-like experiment that allows up to 1,920 detectors to be read out. TDM has been chosen as the detector readout technology for the Cosmic Microwave Background Stage-4 (CMB-S4) experiment based on its proven low-noise performance, predictable costs and overall maturity of the architecture. The heritage for TDM is rooted in mm- and submm-wave experiments dating back 20 years and has since evolved to support a multiplexing factor of 64x in Stage-3 experiments.« less
    Free, publicly-accessible full text available November 29, 2022
  5. ; ; ; ; ; ; ; ; ; ; et al ( , Physical Review D)
    Free, publicly-accessible full text available January 1, 2023
  6. ; ; ; ; ; ; ; ; ; ; et al ( , Physical Review Letters)
    Free, publicly-accessible full text available October 1, 2022
  7. ; ; ; ; ; ; ; ; ; ; et al ( , Physical Review D)
    Full Text Available 
  8. ; ; ; ; ; ; ; ; ; ; et al ( , Journal of Low Temperature Physics)
    Full Text Available 
  9. ; ; ; ; ; ; ; ; ; ; et al ( , Physical review)
    BICEP Keck Collaboration; SPTpol Collaboration;
    Accepted Manuscript Full Text Available
  10. ; ; ; ; ; ; ; ; ; ; et al ( , Physical Review D)
    null (Ed.)
    Full Text Available