Laboratory Integration of the AliCPT-1 Receiver Salatino, Maria; Withers, Matthew O.; Kuo, Chao-Lin ...
IEEE transactions on applied superconductivity,
08/2023, Letnik:
33, Številka:
5
Journal Article
Recenzirano
Ali Cosmic Microwave Background (CMB) Polarization Telescope (AliCPT-1) will be the first large-scale microwave focal plane polarimeter, with <inline-formula><tex-math ...notation="LaTeX">>\!10^{4}</tex-math></inline-formula> detectors, dedicated to ground-based CMB observations in the Northern Hemisphere. The observatory is on the Tibetan plateau. AliCPT-1 will observe the sky with polarization sensitive Transition-Edge Sensors (TESes) in two frequency bands centered at 90 and 150 GHz. A 72 cm aperture refracting cryogenic telescope, cooled down to 4 K, will focus the sky radiation on a focal plane unit designed to host up to 32,376 detectors in 19 detector modules cooled down to 280 mK. The TESes will be read out with a microwave multiplexing architecture with a multiplexing factor up to 1,820 and a RFSoC-based room temperature readout electronics. The first detector and cryogenic multiplexer unit have been separately assembled and characterized under dark conditions. The cryostat has been successfully characterized at cryogenic temperatures, and the basic operation of the warm RFSoC system for a single detector unit has been demonstrated. Here we present the performance of the receiver before the integration of the first detector module. AliCPT-1 is a unique and powerful degree-scale CMB experiment through its combination of a unique site, large focal plane, and new enabling readout technologies.
X‐ray speckle visibility spectroscopy using X‐ray free‐electron lasers has long been proposed as a probe of fast dynamics in noncrystalline materials. In this paper, numerical modeling is presented ...to show how the data interpretation of visibility spectroscopy can be impacted by the nonidealities of real‐life X‐ray detectors. Using simulated detector data, this work provides a detailed analysis of the systematic errors of several contrast extraction algorithms in the context of low‐count‐rate X‐ray speckle visibility spectroscopy and their origins are discussed. Here, it was found that the finite detector charge cloud and pixel size lead to an unavoidable `degeneracy' in photon position determination, and that the contrasts extracted using different algorithms can all be corrected by a simple linear model. The results suggest that experimental calibration of the correction coefficient at the count rate of interest is possible and essential. This allows computationally lightweight algorithms to be implemented for on‐the‐fly analysis.
A numerical model that can mimic closely the behavior of real X‐ray detectors in the context of X‐ray speckle visibility spectroscopy is described. Using this model, this work investigates the origin of discrepancies between commonly used photon locating algorithms and proposes a calibration routine to resolve the discrepancy.
Ali CMB Polarization Telescope (AliCPT) is the first Cosmic Microwave Background (CMB) polarimeter with a large focal plane camera to be deployed in the Northern Hemisphere, in the Tibetan Plateau. ...Here we present the design of a dichroic (90/150 GHz) focal plane camera capable of hosting up to 32,376 Transition-Edge Sensor (TES) bolometers operating from a base temperature of 280 mK. Detectors are fabricated as monolithic arrays of 1,704 feedhorn-coupled and polarization-sensitive TES bolometers that are packaged in independent modules and read out with a microwave multiplexing architecture. A custom RFSoC-based system manages the multiplexing readout. Prototype AliCPT pixels have been fabricated and characterized, demonstrating passband performance within 2.5% of design and cross-polarization systematic sensitivity <inline-formula><tex-math notation="LaTeX">\leq</tex-math></inline-formula>2%.
Quantum systems can not be efficiently simulated classically due to the
presence of entanglement and nonstabilizerness, also known as quantum magic.
Here we study the generation of magic under ...evolution by a quantum circuit. To
be able to provide exact solutions, we focus on the dual-unitary XXZ model and
a measure of magic called stabilizer R\'enyi entropy (SRE). Moreover, we focus
also on long-range SRE, which cannot be removed by short-depth quantum
circuits. To obtain exact solutions we use a ZX-calculus representation and
graphical rules for the evaluation of the required expressions. We obtain exact
results for SRE after short-time evolution in the thermodynamic limit and for
long-range SRE for all times and all R\'enyi parameters for a particular
partition of the state. Since the numerical evaluation of these quantities is
exponentially costly in the R\'enyi parameter, we verify this numerically for
low R\'enyi parameters and accessible system sizes and provide numerical
results for the long-range SRE in other bipartitions.
Ali CMB Polarization Telescope (AliCPT-1) is the first CMB degree-scale polarimeter to be deployed on the Tibetan plateau at 5,250m above sea level. AliCPT-1 is a 90/150 GHz 72 cm aperture, two-lens ...refracting telescope cooled down to 4 K. Alumina lenses, 800mm in diameter, image the CMB in a 33.4{\deg} field of view on a 636mm wide focal plane. The modularized focal plane consists of dichroic polarization-sensitive Transition-Edge Sensors (TESes). Each module includes 1,704 optically active TESes fabricated on a 150mm diameter silicon wafer. Each TES array is read out with a microwave multiplexing readout system capable of a multiplexing factor up to 2,048. Such a large multiplexing factor has allowed the practical deployment of tens of thousands of detectors, enabling the design of a receiver that can operate up to 19 TES arrays for a total of 32,376 TESes. AliCPT-1 leverages the technological advancements in the detector design from multiple generations of previously successful feedhorn-coupled polarimeters, and in the instrument design from BICEP-3, but applied on a larger scale. The cryostat receiver is currently under integration and testing. During the first deployment year, the focal plane will be populated with up to 4 TES arrays. Further TES arrays will be deployed in the following years, fully populating the focal plane with 19 arrays on the fourth deployment year. Here we present the AliCPT-1 receiver design, and how the design has been optimized to meet the experimental requirements.
Quantum systems can not be efficiently simulated classically due to the presence of entanglement and nonstabilizerness, also known as quantum magic. Here we study the generation of magic under ...evolution by a quantum circuit. To be able to provide exact solutions, we focus on the dual-unitary XXZ model and a measure of magic called stabilizer Rényi entropy (SRE). Moreover, we focus also on long-range SRE, which cannot be removed by short-depth quantum circuits. To obtain exact solutions we use a ZX-calculus representation and graphical rules for the evaluation of the required expressions. We obtain exact results for SRE after short-time evolution in the thermodynamic limit and for long-range SRE for all times and all Rényi parameters for a particular partition of the state. Since the numerical evaluation of these quantities is exponentially costly in the Rényi parameter, we verify this numerically for low Rényi parameters and accessible system sizes and provide numerical results for the long-range SRE in other bipartitions.
Food-Based Dietary Guidelines (FBDG) include dietary recommendations based on food groups according to the general and accepted nutrition principles and current scientific evidence. Adoption of FBDG ...contributes to the prevention of malnutrition in all its forms, promotes human health, and reduces environmental impact. The present review aims to perform an international comparative analysis of the FBDG adopted in different countries from three different continents (America, Asia, and Europe), with particular reference to the Spanish Food Safety and Nutrition Agency (AESAN, Agencia Española de Seguridad Alimentaria y Nutrición) Scientific Committee dietary recommendations. A total of twelve countries with the most updated FBDG and/or closest to the traditional and cultural preferences of Spain were finally selected. All the reviewed FBDG provided recommendations for fruits, vegetables, cereals, legumes, nuts, milk and dairy products, meat and derivatives, fish, eggs, water, and oil; however, remarkable differences regarding recommended amounts were found among countries.
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