Meeting in the Middle: Making Use of Popular Culture in the Classroom

The purpose of this paper is to explore the current landscape of the 21st century Introductory Psychology classroom. The authors—graduate students and current teachers of psychology—are well aware of the need to move away from traditional, top-down approaches to teaching. Personal experience has convinced them that the standard lecture format does not engage all 21st century students. A belief in the need to actively engage students in introductory psychology courses is the basis for the present paper. Through the use of technology and active-learning classroom activities, teachers might succeed in meeting students of psychology “where they are,” thus improving the classroom experience for the educator and the student. This paper will explore the idea of teaching of traditional introductory psychology course content using a popular culture medium

The City Symbiotic: Integrating Architecture and Hydrology in the Public Realm

This thesis approaches climate resilience through a comprehensive urban-scale system that incorporates integrated stormwater management to address sea-level rise and urban flooding, while leveraging the power of community as a tool for environmental stewardship. The City Symbiotic has dual notions. At its core, the concept alludes to a mutually beneficial relationship between the built and natural environment. This thesis will be an exploration of designing with water through the lens of climate resilience. Built structures will incorporate an integrated stormwater management network for capturing, filtering, storing, and reusing water, bettering our understanding of the symbiotic relationship between the built and natural environment by blurring the line between the two. The City Symbiotic is also a reference to the relationship between people and their environment. In this respect, this thesis approaches climate resilience through community and connection. Climate change exacerbates existing vulnerabilities that are the result of historical planning failures like Euclidean and exclusionary zoning, urban disinvestment, car-centric planning, environmental racism, and displacement. Reimagining the civic commons as a more inclusive and resilient center of public life can help redress marginalization and inspire environmental stewardship. The outcome of this thesis will demonstrate the value of symbiotic urban design, connecting the built, natural, and human environments to build resilience to water-related impacts of climate change

Online 222Rn^{222}Rn removal by cryogenic distillation in the XENON100 experiment

We describe the purification of xenon from traces of the radioactive noble gas radon using a cryogenic distillation column. The distillation column was integrated into the gas purification loop of the XENON100 detector for online radon removal. This enabled us to significantly reduce the constant $^{222}Rn$ background originating from radon emanation. After inserting an auxiliary $^{222}Rn$ emanation source in the gas loop, we determined a radon reduction factor of $R\,>\,27$ (95% C.L.) for the distillation column by monitoring the $^{222}Rn$ activity concentration inside the XENON100 detector

Search for Electronic Recoil Event Rate Modulation with 4 Years of XENON100 Data

We report on a search for electronic recoil event rate modulation signatures in the XENON100 data accumulated over a period of 4 yr, from January 2010 to January 2014. A profile likelihood method, which incorporates the stability of the XENON100 detector and the known electronic recoil background model, is used to quantify the significance of periodicity in the time distribution of events. There is a weak modulation signature at a period of $431^{+16}_{−14}$ day in the low energy region of (2.0–5.8) keV in the single scatter event sample, with a global significance of 1.9$\sigma$; however, no other more significant modulation is observed. The significance of an annual modulation signature drops from 2.8$\sigma$, from a previous analysis of a subset of this data, to 1.8$\sigma$ with all data combined. Single scatter events in the low energy region are thus used to exclude the DAMA/LIBRA annual modulation as being due to dark matter electron interactions via axial vector coupling at 5.7$\sigma$

Material radiopurity control in the XENONnT experiment

The selection of low-radioactive construction materials is of the utmost importance for rare-event searches and thus critical to the XENONnT experiment. Results of an extensive radioassay program are reported, in which material samples have been screened with gamma-ray spectroscopy, mass spectrometry, and $^{222}Rn$ emanation measurements. Furthermore, the cleanliness procedures applied to remove or mitigate surface contamination of detector materials are described. Screening results, used as inputs for a XENONnT Monte Carlo simulation, predict a reduction of materials background (∼17%) with respect to its predecessor XENON1T. Through radon emanation measurements, the expected $^{222}Rn$ activity concentration in XENONnT is determined to be 4.2 $(^{+0.5}_{−0.7}) μBq/kg$, a factor three lower with respect to XENON1T. This radon concentration will be further suppressed by means of the novel radon distillation system

Erratum: First axion results from the XENON100 experiment [Phys. Rev. D 90, 062009 (2014)]

n our paper, we presented searches for solar axions and galactic axionlike particles (ALPs) in the data collected by the XENON100 experiment (with an exposure of 224.6 days). We recently found a bug in the code to calculate the exclusion limit for galactic ALPs. This resulted in an underestimation of the ALP expected rate, which in turn led to an overly conservative limit, compared to what it should really be. We corrected the code, and the result of the XENON100 90% C.L. exclusion limit on galactic ALPs (shown in Fig. 1) was reevaluated. The corrected limit is stronger than the one previously published by approximately a factor of 5 across all masses and sets the best published limit on the axion-electron coupling, $g_{Ae}$, in the (1–40)  keV/$c^2$ mass range

Removing krypton from xenon by cryogenic distillation to the ppq level

The XENON1T experiment aims for the direct detection of dark matter in a detector filled with 3.3 tons of liquid xenon. In order to achieve the desired sensitivity, the background induced by radioactive decays inside the detector has to be sufficiently low. One major contributor is the β\beta-emitter $^{85}$Kr which is present in the xenon. For XENON1T a concentration of natural krypton in xenon $^{nat}\mathrm{Kr/Xe}\,<\,200\,ppq$ (parts per quadrillion, $1~\mathrm{ppq}~=10^{-15} \mathrm{mol/mol}$) is required. In this work, the design, construction and test of a novel cryogenic distillation column using the common McCabe–Thiele approach is described. The system demonstrated a krypton reduction factor of $6.4\cdot 10^5$ with thermodynamic stability at process speeds above 3 kg/h. The resulting concentration of $^{nat}\mathrm{Kr/Xe}<26\,ppq$ is the lowest ever achieved, almost one order of magnitude below the requirements for XENON1T and even sufficient for future dark matter experiments using liquid xenon, such as XENONnT and DARWIN

Results from a calibration of XENON100 using a source of dissolved radon-220

A $^{220}Rn$ source is deployed on the XENON100 dark matter detector in order to address the challenges in calibration of tonne-scale liquid noble element detectors. We show that the $^{212}Pb$ beta emission can be used for low-energy electronic recoil calibration in searches for dark matter. The isotope spreads throughout the entire active region of the detector, and its activity naturally decays below background level within a week after the source is closed. We find no increase in the activity of the troublesome $^{222}Rn$ background after calibration. Alpha emitters are also distributed throughout the detector and facilitate calibration of its response to $^{222}Rn$. Using the delayed coincidence of $^{220}Rn−^{216}Po$, we map for the first time the convective motion of particles in the XENON100 detector. Additionally, we make a competitive measurement of the half-life of $^{212}Po$, $t_{1/2}=(293.9 \pm(1.0)stat \pm(0.6)sys$)  ns

Search for two-neutrino double electron capture of 124Xe^{124}Xe with XENON100

Two-neutrino double electron capture is a rare nuclear decay where two electrons are simultaneously captured from the atomic shell. For $^{124}Xe$ this process has not yet been observed and its detection would provide a new reference for nuclear matrix element calculations. We have conducted a search for two-neutrino double electron capture from the K shell of $^{124}Xe$ using 7636 kgd of data from the XENON100 dark matter detector. Using a Bayesian analysis we observed no significant excess above background, leading to a lower 90% credibility limit on the half-life $T_{1/2}>6.5×10^{20}$ yr. We have also evaluated the sensitivity of the XENON1T experiment, which is currently being commissioned, and found a sensitivity of $T_{1/2}>6.1×10^{22}$ yr after an exposure of 2 t yr

Search for magnetic inelastic dark matter with XENON100

We present the first search for dark matter-induced delayed coincidence signals in a dual-phase xenon time projection chamber, using the 224.6 live days of the XENON100 science run II. This very distinct signature is predicted in the framework of magnetic inelastic dark matter which has been proposed to reconcile the modulation signal reported by the DAMA/LIBRA collaboration with the null results from other direct detection experiments. No candidate event has been found in the region of interest and upper limits on the WIMP's magnetic dipole moment are derived. The scenarios proposed to explain the DAMA/LIBRA modulation signal by magnetic inelastic dark matter interactions of WIMPs with masses of 58.0 $GeV/c^2$ and 122.7 $GeV/c^2$ are excluded at 3.3 $\sigma$ and 9.3 $\sigma$, respectively