The authors hypothesize that environmental values derive from a sense of connectivity with nature. Connectivity describes a perception of sameness between the self, others, and the natural world. The ...experience of connectivity involves dissolution of boundaries and a sense of a shared or common essence between the self, nature, and others. Connectivity with nature differs theoretically and operationally from other explanations of environmental values, including cultural bias, postmaterialism, and social altruism. The authors describe their development of a sociometric scale to operationalize connectivity with nature. Based on data from a mail survey of Pennsylvania landowners, the authors use multiple regression analyses to determine the extent to which connectivity with nature predicts and explains environmental concern and behavior in the presence of standard sociodemographic variables. Survey respondents reported a high level of connectivity with nature, and connectivity retained a significant and positive relationship to environmental concern and environmental behavior in multiple regression models. Implications of these findings are advanced.
While the ecological importance of riparian forests is widely recognized, identifying the best policies for reforesting privately owned stream lands also requires an understanding of societal ...perceptions. Forty semistructured interviews with riparian landowners in central Pennsylvania revealed a study population driven by competing considerations. On one hand, these landowners expressed a community obligation to consider the downstream consequences of their management styles. On the other, they often failed to appreciate their own contributions to water pollution and were reluctant to abandon the ordered landscapes to which they were accustomed. Possible implications of these findings are advanced.
The Simons Observatory aims to field 70,000 Transition-Edge Sensor (TES) bolometers to measure the Cosmic Microwave Background. With so many detectors, rapid but accurate validation of their ...properties prior to their integration into telescopes is of particular importance. This paper describes an exploration of a new method to improve the simultaneous characterization of TES thermal parameters and bolometer optical efficiencies without significantly increasing the data collection time. The paper uses a special-purpose data set comprising current-voltage (IV) curves collected from thousands of TES bolometers with a variety of different average bath temperatures and different cold load temperatures. A subset of the bolometers were masked so they received no optical power. The new method fits data from the bath temperature ramp and cold load temperature ramps together as one set instead of fitting each independently. This enables thermal parameter assessment of the unmasked detectors without performing additional cooldowns of the cryostat, halving the time necessary to obtain thermal characterization of all detectors.
Abstract
Advances in cosmic microwave background (CMB) science depend on increasing the number of sensitive detectors observing the sky. New instruments deploy large arrays of superconducting ...transition-edge sensor (TES) bolometers tiled densely into ever larger focal planes. High multiplexing factors reduce the thermal loading on the cryogenic receivers and simplify their design. We present the design of focal-plane modules with an order of magnitude higher multiplexing factor than has previously been achieved with TES bolometers. We focus on the novel cold readout component, which employs microwave SQUID multiplexing (
μ
mux). Simons Observatory will use 49 modules containing 70,000 bolometers to make exquisitely sensitive measurements of the CMB. We validate the focal-plane module design, presenting measurements of the readout component with and without a prototype detector array of 1728 polarization-sensitive bolometers coupled to feedhorns. The readout component achieves a 95% yield and a 910 multiplexing factor. The median white noise of each readout channel is 65
pA
/
Hz
. This impacts the projected SO mapping speed by <8%, which is less than is assumed in the sensitivity projections. The results validate the full functionality of the module. We discuss the measured performance in the context of SO science requirements, which are exceeded.
Abstract The Simons Observatory is a cosmic microwave background experiment stationed atop Cerro Toco, at an elevation of 5200 ms in Chile’s Atacama Desert. The receivers of the Observatory will ...contain more than 60,000 transition edge sensor bolometers. In order to read out this large detector count in a scalable manner, we utilize a microwave superconducting quantum interference device (SQUID) multiplexing scheme where each detector is inductively coupled to an rf SQUID, which in turn is inductively coupled to a GHz resonator. More than 2000 SQUIDs and resonators are fabricated on a single 76.2-mm-diameter silicon wafer. To qualify wafers before integration, we cryogenically screen $$\sim$$ ∼ 10% of the devices on each wafer by use of a standard set of measurements. From these data, we report parameter value trends in 47 wafers that were fabricated in the past two years. We show good control in key parameters such as frequency placement, internal quality factor, and response to applied flux. We demonstrate a wafer acceptance yield of 86%.
The Simons Observatory (SO) is a cosmic microwave background instrumentation suite being deployed in the Atacama Desert in northern Chile. The telescopes within SO use three types of dichroic ...transition-edge sensor (TES) detector arrays, with the 90 and 150 GHz Mid-Frequency (MF) arrays containing 65% of the approximately 68,000 detectors in the first phase of SO. All of the 26 required MF detector arrays have now been fabricated, packaged into detector modules, and tested in laboratory cryostats. Across all modules, we find an average operable detector yield of 84% and median saturation powers of (2.8, 8.0) pW with interquartile ranges of (1, 2) pW at (90, 150) GHz, respectively, falling within their targeted ranges. We measure TES normal resistances and superconducting transition temperatures on each detector wafer to be uniform within 3%, with overall central values of 7.5 m
Ω
and 165 mK, respectively. Results on time constants, optical efficiency, and noise performance are also presented and are consistent with achieving instrument sensitivity forecasts.
The Simons Observatory (SO) will detect and map the temperature and polarization of the millimeter-wavelength sky from Cerro Toco, Chile, across a range of angular scales, providing rich data sets ...for cosmological and astrophysical analysis. The SO focal planes will be tiled with compact hexagonal packages, called universal focal-plane modules (UFMs), in which the transition-edge sensor (TES) detectors are coupled to 100 mK microwave-multiplexing electronics. Three different types of dichroic TES detector arrays with bands centered at 30/40, 90/150, and 220/280 GHz will be implemented across the 49 planned UFMs. The 90/150 GHz and 220/280 GHz arrays each contain 1764 TESes, which are read out with two 910x multiplexer circuits. The modules contain a series of routed silicon chips, which are packaged together in a controlled electromagnetic environment and operated at 100 mK. Following an overview of the module design, we report on early results from the first 220/280 GHz UFM, including detector yield, as well as readout and detector noise levels.
Observations of the cosmic microwave background (CMB) form the pillar of our current understanding of cosmology. Maps of the temperature and polarization anisotropies of the CMB encode information ...about the initial conditions of the universe, its matter and energy content, and its evolution over time, setting tight constraints on the parameters of the LCDM cosmological model and probing the physics of inflation. Making these exquisitely precise measurements requires building increasingly sensitive instruments, with larger focal plane areas and ever-greater detector counts. SPT-3G is the latest CMB survey instrument to be installed on the 10-meter South Pole Telescope, utilizing both a larger focal plane and multichroic pixels to raise the detector count to ~16,000, a tenfold increase over its predecessor. SPT-3G will conduct a multi-year survey of a 1500 square-degree patch of sky, producing maps with an unprecedented combination of depth and angular resolution and improving constraints on the CMB power spectrum by over an order of magnitude at small angular scales. In this thesis, I describe the SPT-3G instrument, with special focus on the development and testing of the detectors. I present an analysis of data taken by SPT-3G during the 2018 observing season to produce a measurement of the E-mode polarization power spectrum and temperature-E-mode cross-power spectrum of the CMB over the angular multipole range 300 < ℓ < 3000, and I state the resulting constraints on cosmological parameters.
The Simons Observatory is a ground-based cosmic microwave background instrument to be sited in the Atacama Desert in Chile. SO will deploy 60,000 transition-edge sensors (TES) bolometers in 49 ...separate focal-plane modules across a suite of four telescopes covering three dichroic bands termed low frequency (LF), mid-frequency and ultra-high frequency. Each MF and UHF focal-plane module packages 1720 feedhorn-coupled detectors with cryogenic components for highly multiplexed readout using microwave SQUID multiplexing. In this paper, we describe the testing program we have developed for high-throughput validation of modules after they are assembled. The validation requires measurements of the yield, saturation powers, time constants, noise properties and optical efficiencies. Additional measurements will be performed for further characterization as needed. We describe the methods developed and demonstrate preliminary results from the initial testing of a prototype module.
PDF
