Snowmass Topical Group Summary Report: IF07 -- ASICs and Electronics

This writeup summarizes the work of the Topical Working Group 7 of the Instrumentation Frontier group of the Snowmass 2021 process. Group 'IF07' dealt with issues pertaining to ASICs and Readout Electronics. The community efforts as part of IF07 were organized across 7 white papers submitted to the Snowmass process and available in the arXiv.Comment: arXiv admin note: substantial text overlap with arXiv:2209.1411

Considerations about future hard x-ray area detectors

X-ray sources continue to advance in both intensity and temporal domains, thereby opening new ways to analyze the structure and properties of matter, provided that the resultant x-ray images can be efficiently and quantitatively recorded. In this perspective we focus on specific limitations of pixel area x-ray detectors. Although pixel area x-ray detectors have also advanced in recent years, many experiments are still detector limited. Specifically, there is need for detectors that can acquire successive images at GHz rates; detectors that can accurately measure both single photon and millions of photons per pixel in the same image at frame rates of hundreds of kHz; and detectors that efficiently capture images of very hard x-rays (20 keV to several hundred keV). The data volumes and data rates of state-of-the-art detection exceeds most practical data storage options and readout bandwidths, thereby necessitating on-line processing of data prior to, or in lieu of full frame readouts

Application of Traditional Cooking Methods in Chestnut Processing: Effects of Roasting and Boiling on Secondary Metabolites and Antioxidant Capacity in Castanea spp. Fruits

More information on the effects of traditional cooking methods (roasting or boiling) on the chestnut composition may be important if health-promoting aspects are considered. The main aims of this study were to investigate and describe the phenolic profile and antioxidant capacity of raw, boiled, and roasted chestnuts from several Castanea spp. genotypes, evaluating the influence of the application of different traditional cooking methods on the nut phytochemical composition by chromatographic and spectroscopic strategies. The amounts of phenolics were used as selected variables together with total polyphenol content and antioxidant capacity to perform a Principal Component Analysis (PCA). Catechins and tannins were the main molecules in the phenolic phytocomplex, reaching 30-40% of the total, followed by phenolic acids (5-20%) and flavonols (about 5%). Gallic and ellagic acids were the most important phenolic acids in raw and processed chestnuts (about 20-70 mg center dot 100 g(-1) dried weight-DW and 10-50 mg center dot 100 g(-1) DW, respectively). Both of the cooking processes significantly influenced the polyphenolic content and the relative antioxidant capacity. This research may support and confirm the potential use of chestnuts for human health, increasing the information on the phenolic pattern of differently processed Castanea spp. fruits from different genotypes to (i) assess the potential health-positive effects, (ii) help processing companies to select specific varieties to commercialise in the market, and (iii) increase the use of these fruits with the relative increase in income for the producers

Correction of complex nonlinear signal response from a pixel array detector

The pulsed free-electron laser light sources represent a new challenge to photon area detectors due to the intrinsic spontaneous X-ray photon generation process that makes single-pulse detection necessary. Intensity fluctuations up to 100% between individual pulses lead to high linearity requirements in order to distinguish small signal changes. In real detectors, signal distortions as a function of the intensity distribution on the entire detector can occur. Here a robust method to correct this nonlinear response in an area detector is presented for the case of exposures to similar signals. The method is tested for the case of diffuse scattering from liquids where relevant sub-1% signal changes appear on the same order as artifacts induced by the detector electronics

Stellar Encounter Driven Red-giant Star Mass Loss in Globular Clusters

Globular cluster (GC) color-magnitude diagrams (CMDs) are reasonably well understood in terms of standard stellar evolution. However, there are still some open issues, such as fully accounting for the horizontal branch (HB) morphology in terms of chemical and dynamical parameters. Mass loss on the red giant branch (RGB) shapes the mass distribution of the HB stars, and the color distribution in turn. The physical mechanisms driving mass loss are still unclear, as direct observations fail to reveal a clear correlation between mass-loss rate and stellar properties. The HB mass distribution is further complicated by helium-enhanced multiple stellar populations due to differences in the evolving mass along the HB. We present a simple analytical mass-loss model based on tidal stripping through Roche-Lobe overflow during stellar encounters. Our model naturally results in a non-Gaussian mass-loss distribution with high skewness and contains only two free parameters. We fit it to the HB mass distribution of four Galactic GCs, as obtained from fitting the CMD with zero age HB models. The best-fit model accurately reproduces the observed mass distribution. If confirmed on a wider sample of GCs, our results would account for the effects of dynamics in RGB mass-loss processes and provide a physically motivated procedure for synthetic CMDs of GCs. Our physical modeling of mass loss may result in the ability to disentangle the effects of dynamics and helium-enhanced multiple populations on the HB morphology and is instrumental in making HB morphology a probe of the dynamical state of GCs, leading to an improved understanding of their evolution