Charge dissipative dielectric for cryogenic devices

A Superconducting Quantum Interference Device (SQUID) is disclosed comprising a pair of resistively shunted Josephson junctions connected in parallel within a superconducting loop and biased by an external direct current (dc) source. The SQUID comprises a semiconductor substrate and at least one superconducting layer. The metal layer(s) are separated by or covered with a semiconductor material layer having the properties of a conductor at room temperature and the properties of an insulator at operating temperatures (generally less than 100 Kelvins). The properties of the semiconductor material layer greatly reduces the risk of electrostatic discharge that can damage the device during normal handling of the device at room temperature, while still providing the insulating properties desired to allow normal functioning of the device at its operating temperature. A method of manufacturing the SQUID device is also disclosed

Magnetic field dependence of the internal quality factor and noise performance of lumped-element kinetic inductance detectors

We present a technique for increasing the internal quality factor of kinetic inductance detectors (KIDs) by nulling ambient magnetic fields with a properly applied magnetic field. The KIDs used in this study are made from thin-film aluminum, they are mounted inside a light-tight package made from bulk aluminum, and they are operated near $150 \, \mathrm{mK}$. Since the thin-film aluminum has a slightly elevated critical temperature ($T_\mathrm{c} = 1.4 \, \mathrm{K}$), it therefore transitions before the package ($T_\mathrm{c} = 1.2 \, \mathrm{K}$), which also serves as a magnetic shield. On cooldown, ambient magnetic fields as small as approximately $30 \, \mathrm{\mu T}$ can produce vortices in the thin-film aluminum as it transitions because the bulk aluminum package has not yet transitioned and therefore is not yet shielding. These vortices become trapped inside the aluminum package below $1.2 \, \mathrm{K}$ and ultimately produce low internal quality factors in the thin-film superconducting resonators. We show that by controlling the strength of the magnetic field present when the thin film transitions, we can control the internal quality factor of the resonators. We also compare the noise performance with and without vortices present, and find no evidence for excess noise beyond the increase in amplifier noise, which is expected with increasing loss.Comment: 5 pages, 4 figure

Effects of Strong Capacitive Coupling Between Meta-Atoms in rf SQUID Metamaterials

We consider, for the first time, the effects of strong capacitive and inductive coupling between radio frequency Superconducting Quantum Interference Devices (rf SQUIDs) in an overlapping metamaterial geometry when driven by rf flux at and near their self-resonant frequencies. The equations of motion for the gauge-invariant phases on the Josephson junctions in each SQUID are set up and solved. Our model accounts for the high-frequency displacement currents through capacitive overlap between the wiring of SQUID loops. We begin by modeling two overlapping SQUIDs and studying the response in both the linear and nonlinear high-frequency driving limits. By exploring a sequence of more and more complicated arrays, the formalism is eventually extended to the $N\times N \times 2$ overlapping metamaterial array, where we develop an understanding of the many ($8N^2-8N+3$) resulting resonant modes in terms of three classes of resonances. The capacitive coupling gives rise to qualitatively new self-resonant responses of rf SQUID metamaterials, and is demonstrated through analytical theory, numerical modeling, and experiment in the 10-30 GHz range on capacitively and inductively coupled rf SQUID metamaterials

Reckoning up: sexual harassment and violence in the neoliberal university

This paper situates sexual harassment and violence in the neoliberal university. Using data from a ‘composite ethnography’ representing twelve years of research, I argue that institutional inaction on these issues reflects how they are ‘reckoned up’ in the context of gender and other structures. The impact of disclosure is projected in market terms: this produces institutional airbrushing which protects both the institution and those (usually privileged men) whose welfare is bound up with its success. Staff and students are differentiated by power/value relations, which interact with gender and intersecting categories. Survivors are often left with few alternatives to speaking out in the ‘outrage economy’ of the corporate media: however, this can support institutional airbrushing and bolster punitive technologies. I propose the method of Grounded Action Inquiry, implemented with attention to Lorde’s work on anger, as a parrhesiastic practice of ‘speaking in’ to the neoliberal institution

Civilising the natives? Liberal studies in further education revisited

This paper uses Basil Bernstein’s work on pedagogic discourses to examine a largely neglected facet of the history of vocational education – the liberal studies movement in English further education (FE) colleges. Initially, the paper discusses some of the competing conceptions of education, work and society which underpinned the rise and fall of the liberal studies movement – if indeed it can be described as such. It then draws on data from interviews with former liberal and general studies (LS/GS) lecturers to focus on the ways in which different variants of liberal studies were, over time, implicated in inculcating certain forms of knowledge in vocational learners. Whilst it is acknowledged that LS/GS always represented contested territory and that it was highly variable both in terms of content and quality, the paper argues that, at least and under certain circumstances, liberal studies provided young working-class people with the opportunity to locate their experiences of vocational learning within a critical framework which is largely absent from FE today. This, it is argued, can be conceptualised as an engagement with what Bernstein described as ‘powerful knowledge’

Accuracy of optical spectroscopy for the detection of cervical intraepithelial neoplasia without colposcopic tissue information; a step toward automation for low resource settings

Optical spectroscopy has been proposed as an accurate and low-cost alternative for detection of cervical intraepithelial neoplasia. We previously published an algorithm using optical spectroscopy as an adjunct to colposcopy and found good accuracy (sensitivity ¼ 1.00 [95% confidence interval ðCIÞ ¼ 0.92 to 1.00], specificity ¼ 0.71 [95% CI ¼ 0.62 to 0.79]). Those results used measurements taken by expert colposcopists as well as the colposcopy diagnosis. In this study, we trained and tested an algorithm for the detection of cervical intraepithelial neoplasia (i.e., identifying those patients who had histology reading CIN 2 or worse) that did not include the colposcopic diagnosis. Furthermore, we explored the interaction between spectroscopy and colposcopy, examining the importance of probe placement expertise. The colposcopic diagnosis-independent spectroscopy algorithm had a sensitivity of 0.98 (95% CI ¼ 0.89 to 1.00) and a specificity of 0.62 (95% CI ¼ 0.52 to 0.71). The difference in the partial area under the ROC curves between spectroscopy with and without the colposcopic diagnosis was statistically significant at the patient level (p ¼ 0.05) but not the site level (p ¼ 0.13). The results suggest that the device has high accuracy over a wide range of provider accuracy and hence could plausibly be implemented by providers with limited training

Rationale, Procedures, and Response Rates for a Pilot Study to Sample Cancer Survivors for NCIs Health Information National Trends Survey: HINTS-SEER 2021.

The National Cancer Institutes (NCI) Health Information National Trends Survey (HINTS) is a nationally representative survey of U.S. adults in which 12-17% of respondents report a cancer history. To increase representation from adult cancer survivors, in 2021, NCI sampled survivors from three Surveillance, Epidemiology, and End Results (SEER) program cancer registries: Iowa, New Mexico, and the Greater Bay Area. Sampling frames were stratified by time since diagnosis and race/ethnicity, with nonmalignant tumors and non-melanoma skin cancers excluded. Participants completed a self-administered postal questionnaire. The overall response rate for HINTS-SEER (N = 1,234) was 12.6%; a non-response bias analysis indicated few demographic differences between respondents and the pool of sampled patients in each registry. Most of the sample was 10+ years since diagnosis (n = 722; 60.2%); 392 respondents were 5 to < 10 years since diagnosis (29.6%); and 120 were < 5 years since diagnosis (10.2%). Common cancers included male reproductive (n = 304; 24.6%), female breast (n = 284; 23.0%), melanoma (n = 119; 9.6%), and gastrointestinal (n = 106; 8.6%). Tumors were mostly localized (67.8%; n = 833), with 22.4% (n = 282) regional, 6.2% (n = 72) distant, and 3.7% (n = 47) unknown. HINTS-SEER data are available by request and may be used for secondary analyses to examine a range of social, behavioral, and healthcare outcomes among cancer survivors

Series SQUID Array Amplifiers Optimized for MHz Frequency-Domain Multiplexed Detector Readout

The CMB-S4 next-generation ground-based cosmic microwave background experimental program aims to provide definitive measurements of the early universe using telescopes with ∼500,000 detectors. In this report, we describe the initial results of a project to develop low-noise Series SQUID Array Amplifiers (SSAAs) that are suitable for Frequency Domain Multiplexed (FDM) readout for large CMB instruments. The new series SQUID array amplifier designs exhibit excellent performance characteristics – smooth output characteristics that simplify tuning and operation, high transimpedance (400 V/A), low current noise referred to the input (5.9 pA/Hz½), low input inductance (11 nH), and low power dissipation (18 nW) that for the first time will enable these devices to be co-located on the focal plane of CMB experiments, thereby reducing unwanted parasitics from cabling