Transition Edge Sensor Chip Design of Modular CE{\nu}NS Detector for the Ricochet Experiment

Coherent elastic neutrino-nucleus scattering (CE$\nu$NS) offers a valuable approach in searching for physics beyond the Standard Model. The Ricochet experiment aims to perform a precision measurement of the CE$\nu$NS spectrum at the Institut Laue-Langevin (ILL) nuclear reactor with cryogenic solid-state detectors. The experiment will employ an array of cryogenic thermal detectors, each with a mass of around 30 g and an energy threshold of 50 eV. One section of this array will contain 9 Transition Edge Sensor (TES) based calorimeters. The design will not only fulfill requirements for Ricochet, but also act as a demonstrator for future neutrino experiments that will require thousands of macroscopic detectors. In this article we present an updated TES chip design as well as performance predictions based on a numerical modeling

Comparison of CDMS [100] and [111] oriented germanium detectors

The Cryogenic Dark Matter Search (CDMS) utilizes large mass, 3" diameter $\times$ 1" thick target masses as particle detectors. The target is instrumented with both phonon and ionization sensors and comparison of energy in each channel provides event-by-event classification of electron and nuclear recoils. Fiducial volume is determined by the ability to obtain good phonon and ionization signal at a particular location. Due to electronic band structure in germanium, electron mass is described by an anisotropic tensor with heavy mass aligned along the symmetry axis defined by the [111] Miller index (L valley), resulting in large lateral component to the transport. The spatial distribution of electrons varies significantly for detectors which have their longitudinal axis orientations described by either the [100] or [111] Miller indices. Electric fields with large fringing component at high detector radius also affect the spatial distribution of electrons and holes. Both effects are studied in a 3 dimensional Monte Carlo and the impact on fiducial volume is discussed.Comment: Low Temperature Detector 14 conference proceedings to be published in the Journal of Low Temperature Physic

Students' engagement in school: analyses according to perceived rights and grade level

O “I Congresso Internacional Envolvimento dos Alunos na Escola: Perspetivas da Psicologia e Educação” (ICIEAE) foi organizado no âmbito do “Projeto PTDC/CPE-CED/114362/2009 – Envolvimento dos Alunos na Escola: Diferenciação e Promoção” (EAE-DP), financiado pela Fundação para a Ciência e a Tecnologia (FCT).Enquadramento conceptual: a valorização e a atualidade do construto “Envolvimento dos alunos na escola” (EAE) têm sido salientadas na literatura teórica, observando-se, no entanto, falta de estudos empíricos com instrumentos multidimensionais e validados. Objetivo: procurar respostas para o seguinte problema de investigação: como se distribuem os alunos pelos níveis de envolvimento e de direitos percebidos na escola, como se relacionam estas variáveis, e como é que tal relação é mediada pelo ano de escolaridade? Método: a amostra foi constituída por 685 estudantes das diferentes regiões do país, de ambos os sexos, repartidos pelo 6º, 7º, 9º e 10º ano de escolaridade. Os dados foram recolhidos em contexto de sala aula através de um inquérito que incluiu itens da “Children’s Rights Scale” (Hart et al., 1996; Veiga, 2001) e o questionário “Envolvimento dos Alunos na Escola: Uma Escala Quadri-dimensional”, especificamente com as dimensões cognitiva, afetiva, comportamental e agenciativa (Veiga, 2013), com qualidades psicométricas elevadas. Resultados: As análises de variância dos resultados no envolvimento (anova two-way 2x2), em função do ano (6º e 7º versus 9º e 10º) e dos direitos percebidos (baixos e altos), permitiram encontrar um efeito principal, significativo, do ano na dimensão cognitiva, agenciativa e EAE total; o efeito dos direitos percebidos (DP) manifestou-se em todas as dimensões do EAE, com elevado nível de significância, destacando um superior envolvimento nos alunos com direitos altos; os efeitos significativos da interação das variáveis ano e DP surgiram nas dimensões cognitiva, agenciativa e EAE total. Na dimensão cognitiva, como nas restantes, a interação ficou a dever-se à diminuição do envolvimento do 6º/7º para os 9º/10º anos, no grupo de alunos com direitos altos, ao passo que se manteve estável no grupo com direitos baixos. Conclusões: Os resultados, confrontados com a falta de estudos sobre estes conceitos, são enquadrados na perspetiva cognitivo-social do desenvolvimento na adolescência, relevando a importância da promoção dos direitos dos alunos na escola

Students’ engagement in school, perceived rights and grade level

This article is a product of the project PTDC/CPE-CED/114362/2009 - Envolvimento dos Alunos na escola: Diferenciação e Promoção/Students Engagment in School: Differentiation and Promotion, financed by National funding, through the Fundação para a Ciência e Tecnologia (FCT).Conceptual Framework: the value and contemporaneity of the construct “Students engagement in school” (SES) has been highlighted in the theoretical literature, despite of the lack of empirical studies using validated multidimensional instruments. Purpose: to seek answers to the following research problem: How do students distribute by levels of school engagement and perceived rights, how do these variables relate, and how is such relation mediated by grade level? Method: the sample included 685 students from various regions of the country, from both sexes and divided by 6th, 7th, 9th e 10th grade. The data were collected in classroom context, through a survey which included items from the “Children’s Rights Scale” (Hart et al., 1996; Veiga et al., 2001) and from the questionnaire “Students’ Engagement in School: a Four Dimensional Scale (SES-FDS)”, specifically comprising the cognitive, affective, behavioral and agency dimensions (Veiga, 2013), with high psychometric qualities. Results: Variance analyses of the engagement results (anova two-way 2x2), according to grade level (6th and 7th versus 9th and 10th) and perceived rights (low and high), allowed to find a significant main effect of the grade level in the cognitive and agency dimensions, as well as in SES total score; the effects of the perceived rights (PR) manifested in all SES dimensions, with a high level of significance, being emphasized a higher engagement in students with high rights; the significant effects of the interaction of the variables grade level and PR emerged in the cognitive and agency dimensions, as well as in SES total score. In the cognitive dimension, as in the other, the interaction was due to the decrease of the engagement from 6th/7th to 9th/10th grades, in the group of students with high rights, whereas remaining stable in the group of students with low rights. Conclusions: The results, confronted with the lack of research on these concepts, are considered within the perspective of social-cognitive development in adolescence, emphasizing the importance of promoting students ‘rights in school

Validation of Phonon Physics in the CDMS Detector Monte Carlo

The SuperCDMS collaboration is a dark matter search effort aimed at detecting the scattering of WIMP dark matter from nuclei in cryogenic germanium targets. The CDMS Detector Monte Carlo (CDMS-DMC) is a simulation tool aimed at achieving a deeper understanding of the performance of the SuperCDMS detectors and aiding the dark matter search analysis. We present results from validation of the phonon physics described in the CDMS-DMC and outline work towards utilizing it in future WIMP search analyses.Comment: 6 Pages, 5 Figures, Proceedings of Low Temperature Detectors 14 Conferenc

Analysis of the low-energy electron-recoil spectrum of the CDMS experiment

We report on the analysis of the low-energy electron-recoil spectrum from the CDMS II experiment using data with an exposure of 443.2 kg-days. The analysis provides details on the observed counting rate and possible background sources in the energy range of 2 - 8.5 keV. We find no significant excess in the counting rate above background, and compare this observation to the recent DAMA results. In the framework of a conversion of a dark matter particle into electromagnetic energy, our 90% confidence level upper limit of 0.246 events/kg/day at 3.15 keV is lower than the total rate above background observed by DAMA by 8.9$\sigma$. In absence of any specific particle physics model to provide the scaling in cross section between NaI and Ge, we assume a Z^2 scaling. With this assumption the observed rate in DAMA differs from the upper limit in CDMS by 6.8$\sigma$. Under the conservative assumption that the modulation amplitude is 6% of the total rate we obtain upper limits on the modulation amplitude a factor of ~2 less than observed by DAMA, constraining some possible interpretations of this modulation.Comment: 4 pages, 3 figure

A Search for WIMPs with the First Five-Tower Data from CDMS

We report first results from the Cryogenic Dark Matter Search (CDMS II) experiment running with its full complement of 30 cryogenic particle detectors at the Soudan Underground Laboratory. This report is based on the analysis of data acquired between October 2006 and July 2007 from 15 Ge detectors (3.75 kg), giving an effective exposure of 121.3 kg-d (averaged over recoil energies 10--100 keV, weighted for a weakly interacting massive particle (WIMP) mass of 60 \gev). A blind analysis, incorporating improved techniques for event reconstruction and data quality monitoring, resulted in zero observed events. This analysis sets an upper limit on the WIMP-nucleon spin-independent cross section of 6.6$\times10^{-44}$ cm$^2$ (4.6$\times10^{-44}$ cm$^2$ when combined with previous CDMS Soudan data) at the 90% confidence level for a WIMP mass of 60 \gev. By providing the best sensitivity for dark matter WIMPs with masses above 42 GeV/c$^2$, this work significantly restricts the parameter space for some of the favored supersymmetric models.Comment: 5 pages, 4 figures, submitted to PRL 28 March 200

Characterization of SuperCDMS 1-inch Ge Detectors

The newly commissioned SuperCDMS Soudan experiment aims to search for WIMP dark matter with a sensitivity to cross sections of 5×10^(−45)cm^2 and larger (90% CL upper limit). This goal is facilitated by a new set of germanium detectors, 2.5 times more massive than the ones used in the CDMS-II experiment, and with a different athermal phonon sensor layout that eliminates radial degeneracy in position reconstruction of high radius events. We present characterization data on these detectors, as well as improved techniques for correcting position-dependent variations in pulse shape across the detector. These improvements provide surface-event discrimination sufficient for a reach of 5×10^(−45)cm^2

Results from a Low-Energy Analysis of the CDMS II Germanium Data

We report results from a reanalysis of data from the Cryogenic Dark Matter Search (CDMS II) experiment at the Soudan Underground Laboratory. Data taken between October 2006 and September 2008 using eight germanium detectors are reanalyzed with a lowered, 2 keV recoil-energy threshold, to give increased sensitivity to interactions from Weakly Interacting Massive Particles (WIMPs) with masses below ~10 GeV/c^2. This analysis provides stronger constraints than previous CDMS II results for WIMP masses below 9 GeV/c^2 and excludes parameter space associated with possible low-mass WIMP signals from the DAMA/LIBRA and CoGeNT experiments.Comment: 9 pages, 8 figures. Supplemental material included as ancillary files. v3) Added appendix with additional details regarding energy scale and background