Focal plane transport assembly for the HEAO-B X-ray telescope

The High Energy Astronomy Observatory - Mission B (HEAO-B), an earth orbiting X-ray telescope facility capable of locating and imaging celestial X-ray sources within one second of arc in the celestial sphere, is considered. The Focal Plane Transport Assembly (FPTA) is one of the basic structural elements of the three thousand pound HEAO-B experiment payload. The FPTA is a multifunctional assembly which supports seven imaging X-ray detectors circumferentially about a central shaft and accurately positions any particular one into the focus of a high resolution mirror assembly. A drive system, position sensor, rotary coupler, and detent alignment system, all an integral part of the rotatable portion which in turn is supported by main bearings to the stationary focal plane housing are described

Saturation of Cs2 Photoassociation in an Optical Dipole Trap

We present studies of strong coupling in single-photon photoassociation of cesium dimers using an optical dipole trap. A thermodynamic model of the trap depletion dynamics is employed to extract absolute rate coefficents. From the dependence of the rate coefficient on the photoassociation laser intensity, we observe saturation of the photoassociation scattering probability at the unitarity limit in quantitative agreement with the theoretical model by Bohn and Julienne [Phys. Rev. A, 60, 414 (1999)]. Also the corresponding power broadening of the resonance width is measured. We could not observe an intensity dependent light shift in contrast to findings for lithium and rubidium, which is attributed to the absence of a p or d-wave shape resonance in cesium

Formation of ultracold LiCs molecules

We present the first observation of ultracold LiCs molecules. The molecules are formed in a two-species magneto-optical trap and detected by two-photon ionization and time-of-flight mass spectrometry. The production rate coefficient is found to be in the range 10^{-18}\unit{cm^3s^{-1}} to 10^{-16}\unit{cm^3s^{-1}}, at least an order of magnitude smaller than for other heteronuclear diatomic molecules directly formed in a magneto-optical trap.Comment: 8 pages, 2 figure

The Tails of the Crossing Probability

The scaling of the tails of the probability of a system to percolate only in the horizontal direction $\pi_{hs}$ was investigated numerically for correlated site-bond percolation model for $q=1,2,3,4$.We have to demonstrate that the tails of the crossing probability far from the critical point have shape $\pi_{hs}(p) \simeq D \exp(c L[p-p_{c}]^{\nu})$ where $\nu$ is the correlation length index, $p=1-\exp(-\beta)$ is the probability of a bond to be closed. At criticality we observe crossover to another scaling $\pi_{hs}(p) \simeq A \exp (-b {L [p-p_{c}]^{\nu}}^{z})$. Here $z$ is a scaling index describing the central part of the crossing probability.Comment: 20 pages, 7 figures, v3:one fitting procedure is changed, grammatical change

Holiday Lights Create Light Pollution and Become Ecological Trap for Eastern Fox Squirrels: Case Study on a University Campus

Ecological light pollution is now recognized as a significant source of ecosystem alteration. We documented that holiday lights are a seasonal source of light pollution that constitute an ecological trap for eastern fox squirrels (Sciurus niger). Texas A&M University-Kingsville (TAMUK) wildlife students surveyed a 2-km walking transect 5 times per month each month for the relative abundance and diel behavior of eastern fox squirrels and feral cats (Felis catus) on the TAMUK campus during 2018–2019. Eastern fox squirrels exhibited diurnal behaviors throughout the year but extended their foraging behavior nearly 4 hours after sunset with the addition of holiday lights. Feral cats and owls (Strigiformes) exhibited diurnal and nocturnal behaviors but conducted the majority of their hunting during crepuscular hours. We documented that monthly squirrel mortality increased 7-fold with the addition of holiday lights, possibly due to the extension of foraging time by squirrels. Although seasonal lighting is intended to be festive for humans, it can have negative consequences for eastern fox squirrels. Educating the public concerning the issue of light pollution on wildlife species is needed because the majority of the public appears unaware that bright lights can negatively alter wildlife behaviors. Reducing light intensity by either using less outdoor lights or perhaps using colored lights rather than clear white bulbs may lessen the negative effect on foraging behavior of squirrels