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Full-Text Articles in Physical Sciences and Mathematics
Analytical Results For The Three-Body Radiative Attachment Rate Coefficient, With Application To The Positive Antihydrogen Ion H̄+, Jack C. Straton
Analytical Results For The Three-Body Radiative Attachment Rate Coefficient, With Application To The Positive Antihydrogen Ion H̄+, Jack C. Straton
Physics Faculty Publications and Presentations
To overcome the numerical difficulties inherent in the Maxwell–Boltzmann integral of the velocity-weighted cross section that gives the radiative attachment rate coefficient αRA for producing the negative hydrogen ion H− or its antimatter equivalent, the positive antihydrogen ion H¯+ , we found the analytic form for this integral. This procedure is useful for temperatures below 700 K, the region for which the production of H¯+ has potential use as an intermediate stage in the cooling of antihydrogen to ultra-cold (sub-mK) temperatures for spectroscopic studies and probing the gravitational interaction of the anti-atom. Our results, utilizing a 50-term …
Polarization In The Production Of The Antihydrogen Ion, Casey A. Yazejian, Jack C. Straton
Polarization In The Production Of The Antihydrogen Ion, Casey A. Yazejian, Jack C. Straton
Physics Faculty Publications and Presentations
We provide estimates of both the cross section and rate coefficient for the radiative attachment of a second positron to create the H̅+ ion, H̅(1s)+e+→H̅+(1s2 1Se)+ℏω, for which the polarization of the initial state H̅(1s) is taken into account. We show how to analytically integrate the resulting six-dimensional, three-body integrals for wave functions composed of explicitly correlated exponentials, a result that may be extended to Hylleraas wave functions. We extend Bhatia’s polarization results for the equivalent matter problem down to the low temperatures required for the Gravitational Behaviour of Antihydrogen …
Enhancing Final Image Contrast In Off-Axis Digital Holography Using Residual Fringes, Manuel Bedrossian, Kent Wallace, Eugene Serabyn, Chris Lindensmith, Jay Nadeau
Enhancing Final Image Contrast In Off-Axis Digital Holography Using Residual Fringes, Manuel Bedrossian, Kent Wallace, Eugene Serabyn, Chris Lindensmith, Jay Nadeau
Physics Faculty Publications and Presentations
We show that background fringe-pattern subtraction is a useful technique for removing static noise from off-axis holographic reconstructions and can enhance image contrast in volumetric reconstructions by an order of magnitude in the case for instruments with relatively stable fringes. We demonstrate the fundamental principle of this technique and introduce some practical considerations that must be made when implementing this scheme, such as quantifying fringe stability. This work also shows an experimental verification of the background fringe subtraction scheme using various biological samples.
Predicting Densities And Elastic Moduli Of Sio2-Based Glasses By Machine Learning, Yong-Jie Hu, Ge Zhao, Mingfei Zhang, Bin Bin, Tyler Del Rose, Qian Zhao, Qan Zu, Yang Chen, Xuekun Sun, Maarten De Jong, Multiple Additional Authors
Predicting Densities And Elastic Moduli Of Sio2-Based Glasses By Machine Learning, Yong-Jie Hu, Ge Zhao, Mingfei Zhang, Bin Bin, Tyler Del Rose, Qian Zhao, Qan Zu, Yang Chen, Xuekun Sun, Maarten De Jong, Multiple Additional Authors
Mathematics and Statistics Faculty Publications and Presentations
Chemical design of SiO2-based glasses with high elastic moduli and low weight is of great interest. However, it is difficult to find a universal expression to predict the elastic moduli according to the glass composition before synthesis since the elastic moduli are a complex function of interatomic bonds and their ordering at different length scales. Here we show that the densities and elastic moduli of SiO2-based glasses can be efficiently predicted by machine learning (ML) techniques across a complex compositional space with multiple (>10) types of additive oxides besides SiO2. Our machine learning approach relies on a training set …