Precise photographic monitoring of MEG II thin-film muon stopping target position and shape
Not provided.
Instruments & Instrumentation↗
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Results for “precision”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Deformation-induced morphology evolution of precise polyethylene ionomers
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Middleton, L. Robert (ORCID:000000019562573X)↗
Genome-scale engineering of Saccharomyces cerevisiae with single-nucleotide precision
Here, we developed a CRISPR/Cas9 and homology-directed-repair assisted genome-scale engineering method named CHAnGE that can rapidly output tens of thousands of specific genetic variants in yeast. More than 98% of target sequences were efficiently edited with an average frequency of 82%. We validate the single-nucleotide resolution genome-editing capability of this technology by creating a genome-wide gene disruption collection and apply our method to improve tolerance to growth inhibitors.
59 BASIC BIOLOGICAL SCIENCES↗
The laser micro-machining system for diamond anvil cell experiments and general precision machining applications at the High Pressure Collaborative Access Team
We report we have designed and constructed a new system for micro-machining parts and sample assemblies used for diamond anvil cells and general user operations at the High Pressure Collaborative Access Team, sector 16 of the Advanced Photon Source. The new micro-machining system uses a pulsed laser of 400 ps pulse duration, ablating various materials without thermal melting, thus leaving a clean edge. With optics designed for a tight focus, the system can machine holes any size larger than 3 μm in diameter. Unlike a standard electrical discharge machining drill, the new laser system allows micro-machining of non-conductive materials such as: amorphous boron and silicon carbide gaskets, diamond, oxides, and other materials including organic materials such as polyimide films (i.e., Kapton). An important feature of the new system is the use of gas-tight or gas-flow environmental chambers which allow the laser micro-machining to be done in a controlled (e.g., inert gas) atmosphere to prevent oxidation and other chemical reactions in air sensitive materials. The gas-tight workpiece enclosure is also useful for machining materials with known health risks (e.g., beryllium). Specialized control software with a graphical interface enables micro-machining of custom 2D and 3D shapes. The laser-machining system was designed in a Class 1 laser enclosure, i.e., it includes laser safety interlocks and computer controls and allows for routine operation. Though initially designed mainly for machining of the diamond anvil cell gaskets, the laser-machining system has since found many other micro-machining applications, several of which are presented here.
47 OTHER INSTRUMENTATION↗
Non-degenerate two photon absorption enhancement for laser dyes by precise lock-in detection
This study demonstrates a measurement system for a non-degenerate two-photon absorption (NDTPA) spectrum. The NDTPA light sources are a white light super continuum beam (WLSC, 500 ∼ 720 nm) and a fundamental beam (798 nm) from a Ti:Sapphire laser. A reliable broadband NDTPA spectrum is acquired in a single-shot detection procedure using a 128-channel lock-in amplifier. The NDTPA spectra for several common laser dyes are measured. Two photon absorption cross section enhancements are found in the experiment and validated by theoretical calculation for all of the chromophores.
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
X-ray diffraction gratings: Precise control of ultra-low blaze angle via anisotropic wet etching
Diffraction gratings are used from micron to nanometer wavelengths as dispersing elements in optical instruments. At shorter wavelengths, crystals can be used as diffracting elements, but due to the 3D nature of the interaction with light are wavelength selective rather than wavelength dispersing. There is an urgent need to extend grating technology into the x-ray domain of wavelengths from 1 to 0.1 nm, but this requires the use of gratings that have a faceted surface in which the facet angles are very small, typically less than 1°. Small facet angles are also required in the extreme ultra-violet and soft x-ray energy ranges in free electron laser applications, in order to reduce power density below a critical damage threshold. In this work, we demonstrate a technique based on anisotropic etching of silicon designed to produce very small angle facets with a high degree of perfection.
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
Precise absolute γ -ray and β - -decay branching intensities in the decay of Cu 29 67
In this work, absolute γ-ray emission probabilities in the β - decay of 67 Cu were measured by means of γ-ray and β - -decay singles and β - -γ coincidences. The new results, together with the known decay scheme of 67 Cu , were used to determine absolute β - -decay branching intensities. The present data differ significantly from previously published values. In addition, the half-life of the I π = 1/2 - isomer in 67 Zn was measured as T 1/2 = 9.37(4) μs, in a good agreement with earlier measurements. Lastly, from the analysis of the Fermi–Kurie plots, Q β - ( g.s.) = 560.3 (10) keV was deduced, which differs from the previously measured value of 577(8) keV but is in good agreement with Q β - ( g.s.) = 561.3 (15) keV recommended in the latest Atomic Mass Evaluation.
73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
Acoustic scaling of linear and mode-coupled anisotropic flow; implications for precision extraction of the specific shear viscosity
The n th -order linear flow coefficients v n L ( n = 2 , 3 , 4 , 5 ) , and the corresponding nonlinear mode-coupled ( mc ) coefficients v 4 , ( 2 , 2 ) mc , v 5 , ( 2 , 3 ) mc , v 6 , ( 3 , 3 ) mc , and v 6 , ( 2 , 2 , 2 ) mc , are studied for Pb+Pb collisions at s N N = 2.76 TeV. Both sets of coefficients suggest a common acoustic scaling pattern of exponential viscous modulation, with a rate proportional to the square of the harmonic numbers and the mean transverse momenta (respectively), and inversely proportional to the cube root of the charged particle multiplicity [ ( N ch ) 1 / 3 ] , which characterizes the dimensionless size of the systems produced in the collisions. These patterns and their associated scaling parameters offer new stringent constraints for eccentricity-independent estimates of the specific shear viscosity η s ( T ) and the viscous correction to the thermal distribution function for the matter produced in the collisions. They also give crucial constraints for extraction of the initial-state eccentricity spectrum.
73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗