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Full-Text Articles in Physics
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 …
Acoustics To Quantum Materials: A Centennial History Of The Department Of Physics, University Of Arkansas, Rajendra Gupta, Paul C. Sharrah
Acoustics To Quantum Materials: A Centennial History Of The Department Of Physics, University Of Arkansas, Rajendra Gupta, Paul C. Sharrah
Physics Faculty Publications and Presentations
The department of physics at the University of Arkansas was established in the 1907-08 academic year, although physics was taught from the very start of the University in 1872. The department celebrated its centennial in 2007-2008. Acoustics to Quantum Materials is a centennial history of the department covering the period 1907-08 to 2007-08. While the emphasis is on this period, instruction of physics over the period 1872-1907 is covered in two prologues, and the period 2009-18 is briefly covered in an epilogue. The first research laboratory to be established was in the area of acoustics. Subsequently, the department’s faculty have …
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.
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 …