# Bulletin of the American Physical Society

# Fall 2020 Meeting of the APS New England Section

## Volume 65, Number 21

## Friday–Saturday, November 6–7, 2020; Virtual

## Session D01: Contributed: Optics |
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Chair: Brian Wells, University of Hartford |

Saturday, November 7, 2020 11:00AM - 11:15AM |
D01.00001: Bridgewater State University Physics Builds Photonics and Optical Engineering BS Degree Program Ed Deveney, Elif Demirbas, Samuel Serna, Thomas Kling Over the past twenty years Bridgewater State University (BSU), Bridgewater MA, has built a thriving undergraduate Physics department and program recognized for the numbers of graduating majors, innovative STEM teaching and retention initiatives, awarded undergraduate research and highly needed high school physics teachers.~ Strategic emphasis over that period on advanced, or Beyond first Year (BFY), laboratory experiences, optics based research interests (laser cooling and trapping and optical tweezers), as well three new faculty hires have resulted in a niche of graduates with strong quantum, optics and engineering backgrounds who have gone on to graduate schools and, significantly, workforce for local photonic and optics based industries.~~ In this talk, we chronicle these developments as they have catalyzed recent capital equipment awards, collaborations and connections to MA state and federal programs in photonics and quantum technologies.~~ Recently, BSU Physics has added a public four-year BS program in Photonics and Optical Engineering a result threaded throughout the talk.~~ We detail, why, how and what we did to get to this as an example for other departments looking to expand in similar ways. [Preview Abstract] |

Saturday, November 7, 2020 11:15AM - 11:30AM |
D01.00002: Laser Light Scattering for Mask Filtration Effectiveness Marcus Alcantara Silva, Nimmi Sharma With the ongoing COVID-19 pandemic concerns over the effectiveness of different mask materials in helping to prevent the spread of the virus, a simple way to quantify mask filtration effectiveness of different size particles would be desirable. Thus, studies were conducted to see if an inexpensive sensor could be helpful in assessing air filtration for different mask materials. A dual laser particle counter was used to irradiate suspended aerosol particulates in sampled air with laser light to obtain the scattered light over time. Then, using Mie scattering theory, the scattered intensity was used to calculate the number of particles with different diameters, from 0.3 to 10.0 $\mu $m. This study investigates the effectiveness of different mask materials in removing small particles from ambient air samples. [Preview Abstract] |

Saturday, November 7, 2020 11:30AM - 11:45AM |
D01.00003: Rotational Relaxation Process for Argon-Nitrogen Mixed Gaseous Thermal Plasma Using DSMC Simulations. Sahadev Pradhan In this study we investigate the rotational relaxation process for Argon-Nitrogen mixed gaseous thermal plasma with initial state composition 75 mol{\%} of Argon and 25 mol{\%} of Nitrogen, having two rotational degrees of freedom for Nitrogen molecules and with no internal degrees of freedom for Argon and electron using Direct Simulation Monte Carlo (DSMC) simulations. The Larsen-Borgnakke model is applied on a single molecular basis in which the relaxation collision number is approximated by the reciprocal of the fraction of inelastic collisions. The DSMC simulations are carried out for rotational relaxation collision number $Z_{r} =$\textit{ 7.5 }associated with \quad the Nitrogen molecule and $Z_{r} =$\textit{ 1 }for Argon and electron with viscosity temperature index $? =$\textit{ 0.75} (VHS model), $? =$\textit{ 1.0} (Maxwell model), and ? \quad $=$\textit{ 0.5} (HS model), having different collision rates. The DSMC simulations are compared with the theoretical predictions for translational and rotational temperatures, defined by $T_{tr\thinspace }= T_{eq} + (T_{tr,0\thinspace }-- T_{eq\thinspace })_{\thinspace }$\textit{exp(- }$\nu t/Z_{r}),$ and $T_{rot\thinspace }= T_{eq} -- (T_{eq}- T_{rot,0})_{\thinspace }$\textit{exp(- }$\nu t/Z_{r}) $respectively as well as for the molecular velocity distribution and rotational energy distribution, and found excellent agreement (error within 5{\%}), and the collision process do not lead to any distortion of the Maxwellian velocity distribution and the Boltzmann distribution for the energy. -/a [Preview Abstract] |

Saturday, November 7, 2020 11:45AM - 12:00PM |
D01.00004: The Energy Eigenvalue for the Singular Wave Function of the Three Dimensional Dirac Delta Schrodinger Potential via Distributionally Generalized Quantum Mechanics Michael Maroun In order to generalize models of frequency combs to frequency brushes (2d) and frequency lattices (3d or more), one must be able to model first one delta function. These generalizations are known in classical signal theory. However in the quantum case, the problem is significantly different. In a quantum model where the Schrodinger equation is used as the quantum analogue, the obstruction in 3d for the Schrodinger equation, with the Dirac delta as a pseudo-potential (PP), comes from the bound state being singular at the point support of the delta PP. The problem is solved here in a mathematically rigorous manner that does not use renormalization or regularization. There is no appeal to self-adjoint extensions because the method involves a distributionally generalized version of the Schrodinger theory as developed by the author, which regards the formal symbol "$H\psi$" as an element of the space of distributions. Two main facts come to light. The first is the bound state energy of such a system can be calculated in a well-posed context, the value of which agrees with both the mathematics and theoretical physics literature. The second fact is that there is then a rigorous distributional version of the Hellmann-Feynman theorem. [Preview Abstract] |

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