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Thermal ionization mass spectrometry (TIMS) is a “gold standard’ technique for actinide isotope amount ratio and assay measurements. • Ubiquitously used in: • Nuclear Nonproliferation • Nuclear Safeguards • Nuclear Forensics • Basic Science • Savannah River National Laboratory (SRNL) installed a new Thermo Scientific TRITON Plus TIMS in early 2024.
Production of nuclear clusters such as deuterons, tritons, helions and alpha particles has only recently been simulated for neutrino-nucleus interactions, and has not yet been measured in neutrino experiments. The Short-Baseline Near Detector (SBND) is the first Liquid Argon Time Projection Chamber (LArTPC) with high enough resolution and a large enough neutrino flux to accurately measure the cross-section for the production of heavier-than-proton fragments in neutrino interactions. SBND is a 112-ton LArTPC, and lies 110 m downstream from the Booster Neutrino Beam target, where it has already collected the world's largest dataset of neutrino-argon interactions. In these processes, the intranuclear cascade and nuclear de-excitation stages can both produce nuclear clusters. With LArTPC technology's excellent reconstruction capabilities and SBND's unprecedented neutrino statistics, a measurement of these nuclear clusters could distinguish between nuclear models and improve neutrino energy reconstruction. This poster presents the status of simulation, reconstruction, and prospects for a measurement of nuclear clusters in SBND.
Acoustic emissions from current energy converters remain an environmental concern for regulators because of their potential effects on marine life and uncertainties about their effects stemming from a lack of sufficient observational data. Several recent opportunities to characterize tidal turbine sound emissions have begun to fill knowledge gaps and provide a context for future device deployments. In July 2021, a commercial-off-the-shelf hydrophone was deployed in a free-drifting configuration to measure underwater acoustic emissions and characterize a 25 kW-rated tidal turbine at the University of New Hampshire’s Living Bridge Project in Portsmouth, New Hampshire. Sampling methods and analysis were performed in alignment with the recently published IEC 62600-40 Technical Specification for acoustic characterization of marine energy converters. Results from this study indicate acoustic emissions from the turbine were below ambient sound levels and therefore did not have a significant impact on the underwater noise levels of the project site. As a component of Pacific Northwest National Laboratory’s Triton Field Trials (TFiT) described in this Special Issue, this effort provides a valuable use case for the IEC 62600-40 Technical Specification framework and further recommendations for cost-effective technologies and methods for measuring underwater noise at future current energy converter project sites.
As the wave energy sector grows and looks to the Blue Economy for commercialization opportunities, there is a distinct and pressing need to clearly understand and quantify the coupled impacts of wave energy converter (WEC) size and wave resource characteristics on the annual energy production, spatial variability and temporal variability. Utilizing generic frequency domain representations of the Oscilla Power Triton WEC and spectral wave conditions at PacWave (Oregon), Los Angeles (California) and WETS (Hawaii), a series of interesting results emerge. Firstly, the ‘optimal’ WEC size, from an energy standpoint, is fundamentally dependent on the frequency distribution of the incoming wave variance density spectrum. Secondly, and from a seasonality perspective, the seasonal WEC energy generation doesn’t necessarily follow the seasonal distribution of gross wave power. Finally, from an hourly power variability perspective, a reduction in WEC size generally decreases variability. However, for each of the locations investigated, there appears to be a WEC size threshold; a threshold where further reducing WEC size results in increased power variability.
Abstract. This study evaluates the impact of potential future climate change on flood regimes, floodplain protection, and electricity infrastructures across the Conasauga River watershed in the southeastern United States through ensemble hydrodynamic inundation modeling. The ensemble streamflow scenarios were simulated by the Distributed Hydrology Soil Vegetation Model (DHSVM) driven by (1) 1981–2012 Daymet meteorological observations and (2) 11 sets of downscaled global climate models (GCMs) during the 1966–2005 historical and 2011–2050 future periods. Surface inundation was simulated using a GPU-accelerated Two-dimensional Runoff Inundation Toolkit for Operational Needs (TRITON) hydrodynamic model. A total of 9 out of the 11 GCMs exhibit an increase in the mean ensemble flood inundation areas. Moreover, at the 1 % annual exceedance probability level, the flood inundation frequency curves indicate a ∼ 16 km2 increase in floodplain area. The assessment also shows that even after flood-proofing, four of the substations could still be affected in the projected future period. The increase in floodplain area and substation vulnerability highlights the need to account for climate change in floodplain management. Overall, this study provides a proof-of-concept demonstration of how the computationally intensive hydrodynamic inundation modeling can be used to enhance flood frequency maps and vulnerability assessment under the changing climatic conditions.
A Flash Attention Triton kernel with support for second-order derivatives, such as Jacobian-Vector Products (JVPs) and Hessian-Vector Products (HVPs).
Deuterons and tritons determined for top of earth atmosphere, using grain density vs residual range in nuclear emulsion stack
Neptunian planet-satellite system, discussing orbital motion of Triton
Alpha particle-triton reaction on scandium 45 at 41 MeV
Recent results on the composition and structure of the atmospheres of Jupiter, Saturn, Uranus, Neptune, Pluto, and their satellites are summarized with an orientation toward topics of particular interest to the subject of exobiology. The need for an accurate Jovian temperature profile is noted, and current values are given for the known H2, NH3, and CH4 abundances of each planet as well as Titan and Triton. Trace constituents and chromophores in the Jovian atmosphere are discussed, the role of comets as a link between chemical evolution in the solar system and the chemistry of the interstellar medium is examined, and some features in the IR spectrum of Titan are interpreted. The hope is expressed that Titan will remain a useful proving ground for theories of low-temperature abiogenic organic-compound production
Recent advances in the theory of rotation are combined with traditional approaches to study the rotational evolution of the 33 known natural satellites. A calculation similar to that reported by Burns and Safronov (1973) is applied to each satellite to obtain the characteristic time of decay of any wobble motion to smooth rotation about the principal axis of maximum moment of inertia. Stability criteria and capture probabilities are calculated for the 3/2 spin resonance. Results show that only the regular satellites and Iapetus, Hyperion, Triton, and the moon are tidally evolved. Of these, 13 have confirmed synchronous rotation periods; capture probabilities into the 3/2 resonance indicate that none of the remaining 10 should be captured in nonsynchronous, commensurate spin states. For the most part, the irregular satellites retain their original spins except for a relaxation to principal axis rotation. Tidal evolution of the obliquities of the satellites is evaluated in the framework of the generalization of Cassini's laws for the moon. Nearly resonant, forced librations in longitude of 4.8 and 0.5 deg are calculated on the basis of the observed shapes of Phobos and Deimos, respectively.
From near-infrared photometry (JHKL) of small bodies in the outer solar system a previously unrecognized class of planetary satellites is identified which may have surfaces mostly free of frosts of water, methane, or ammonia. These bodies - including two satellites of Uranus (Titania and Oberon), and one each of Saturn (Hyperion) and Neptune (Triton) - have surfaces characterized by neutral reflectance between J and H (1.25 and 1.60 microns) and rapidly decreasing reflectance at K (2.2 microns) and L (3.5 microns). It is pointed out that the 15 solid bodies in the outer solar system that have been satisfactorily observed (excluding the asteroids) fall into six classes according to spectral reflectance. The presence of water frost or ice on the surface of Enceladus is established.
Known properties of the current solar system and Bodenheimer's (1977) model of early Jovian evolution are employed to develop a mechanism for satellite capture based on gas drag in primordial circumplanetary envelopes. In particular, the deceleration and fragmentation of two parent bodies passing through an extended primordial Jovian nebula may account for the clusters of prograde and retrograde satellites of Jupiter. Subsequently, the fragments probably underwent limited orbital evolution, and were dispersed by collision with a stray body. The heavy element cores of the outer planets may also be due to primordial gas drag capture. Nebular drag capture of the Martian satellites Phobos and Deimos, Neptune's Nereid and Triton, and Saturn's Phoebe and Iapetus is also conceivable.
The mechanism of excitation of laser gases by fast ions (triton, proton, or fission fragments) and especially any role UF6 might play in radiative deexcitation of these gases were investigated. Population densities of excited important for laser action were obtained. Nuclear pumped CW-laser systems, especially He-Ne and CO2, were studied using steady state reactors. It was demonstrated that He-Ne lases in a CW-mode with nuclear pumping at both the red and the infrared transition. The infrared transition was observed to be superradiant.
An infrared spectroscopic data base is described for such planetary studies as (1) the detection of atmospheric constituents, (2) the establishment of the column abundances of known atmospheric constituents, and (3) the determination of the thermal properties of planetary atmospheres. Jupiter, Saturn, Uranus, Neptune, Titan and Triton are discussed with reference to middle- and far-IR data, the chemical and thermal properties of their atmospheres, atmospheric constituents and absolute reflectivities, or albedos. Attention is also given to infrared spectroscopic studies of satellite and asteroid surfaces. It is noted that the most abundant surface materials are condensed volatiles and silicate minerals. Water ice has been detected on many surfaces and on the rings of Saturn; CH-4 has been found on Pluto, and CO2 has been identified as a component of the polar caps on Mars. It is concluded that some asteroid surfaces are mineralogically compatible with the relatively unevolved low-temperature remnant of nebular condensation, while others are composed of high-temperature silicates spectrally identical to the products of magmatic differentiation.
The detection of CH4 frost on Pluto's surface implies a significant atmosphere for Pluto. Although Pluto's mass is small, about 7% of Triton's mass, the rapid escape ('blowoff') of gaseous CH4 can be prevented by the presence of a heavy gas mixed with the CH4. The resulting slow escape ('Jeans escape') of CH4 can be accommodated by sublimation of the surface CH4 frost so that an atmosphere exists in the steady state. A heavier gas must exist, otherwise the CH4 frost would have sublimated away long ago because of solar heat and rapid blowoff of gaseous CH4. Pluto is currently near perihelion where the CH4 component of the atmosphere may be 500 times denser than at apehelion. Significant seasonal changes in the atmospheric bulk are therefore possible.
Widely varying paths of evolutionary history, atmospheric processes, solar fluxes, and temperatures have produced vastly different planetary atmospheres. The similarities and differences between the earth atmosphere and those of the terrestrial planets (Venus and Mars) and of the Jovian planets are discussed in detail; consideration is also given to the photochemistry of Saturn, Uranus, Pluto, Neptune, Titan, and Triton. Changes in the earth's ancient atmosphere are described, and problems of interest in the earth's present troposphere are discussed, including the down wind effect, plume interactions, aerosol nucleation and growth, acid rain, and the fate of terpenes. Temperature fluctuations in the four principal layers of the earth's atmosphere, predicted decreases in the ozone concentration as a function of time, and spectra of particles in the earth's upper atmosphere are also presented. Finally, the vertical structure of the Venus cloud system and the thermal structure of the Jovian planets are shown graphically.
The most recent comprehensive results on spectrophotometric remote sensing of planets and satellites are reviewed. The moon and terrestrial planets are considered in terms of individual surface elements, reflectance spectra being analyzed to show the composition of the soils of these bodies. For more distant, unresolved objects, including the asteroids, the Galilean satellites, the small satellites of Jupiter, the rings and satellites of Saturn and Uranus, as well as Triton and Pluto, the global or hemispheric averages of surface composition are the objects of study. The absorptions due to methane gas and frost are indicated.