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Results for “QUALITY FACTOR”
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Error analysis for intrinsic quality factor measurement in superconducting radio frequency resonators
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Unprecedented quality factors at accelerating gradients up to 45 MVm −1 in niobium superconducting resonators via low temperature nitrogen infusion
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High-Quality-Factor Superconducting Cavities in Tesla-Scale Magnetic Fields for Dark-Matter Searches
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Quench-Induced Degradation of the Quality Factor in Superconducting Resonators
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Understanding Quality Factor Degradation in Superconducting Niobium Cavities at Low Microwave Field Amplitudes
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Characterizing Quality Factor of Niobium Resonators Using a Markov Chain Monte Carlo Approach
The next generation of radiation detectors in high precision Cosmology, Astronomy, and particle-astrophysics experiments will rely heavily on superconducting microwave resonators and kinetic inductance devices. Understanding the physics of energy loss in these devices, in particular at low temperatures and powers, is vital. We present a comprehensive analysis framework, using Markov Chain Monte Carlo methods, to characterize loss due to two-level system in concert with quasi-particle dynamics in thin-film Nb resonators in the GHz range.
PRESERVATION OF THE HIGH QUALITY FACTOR AND ACCELERATING GRADIENT OF Nb3Sn-COATED CAVITY DURING PAIR ASSEMBLY
Two CEBAF 5-cell accelerator cavities have been coated with Nb3Sn film using the vapor diffusion technique. One cavity was coated in the Jefferson Lab Nb3Sn cavity coating system, and the other in the Fermilab Nb3Sn coating system. Both cavities were measured at 4 K and 2 K in the vertical dewar test in each lab and then assembled into a cavity pair at Jefferson Lab. Previous attempts to assemble Nb3Sn cavities into a cavity pair degraded the superconducting properties of Nb3Sn-coated cavities. This contribution discusses the efforts to identify and mitigate the pair assembly challenges and will present the results of the vertical tests before and after pair assembly. Notably, one of the cavities reached the highest gradient above 80 mT in the vertical test after the pair assembly.
DETERMINATION OF LIGAMENT QUALITY FACTORS IN ADDITIVELY MANUFACTURED LATTICE STRUCTURES USING IN-SITU COMPRESSION TESTING MICRO-CT
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Preservation of the High Quality Factor and Accelerating Gradient of Nb3Sn-coated Cavity During Pair Assembly
Two CEBAF 5-cell accelerator cavities have been coated with Nb3Sn film using the vapor diffusion technique. One cavity was coated in the Jefferson Lab Nb3Sn cavity coating system, and the other in the Fermilab Nb3Sn coating system. Both cavities were measured at 4 K and 2 K in the vertical dewar test in each lab and then assembled into a cavity pair at Jefferson Lab. Previous attempts to assemble Nb3Sn cavities into a cavity pair degraded the superconducting properties of Nb3Sn-coated cavities. This contribution discusses the efforts to identify and mitigate the pair assembly challenges and will present the results of the vertical tests before and after pair assembly. Notably, one of the cavities reached the highest gradient above 80 mT in the vertical test after the pair assembly.
A Multi-Region ACA-Accelerated Approach for High-Quality-Factor Resonant Cavities
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A Simple Algebraic Approximate Inverse Preconditioning Scheme for High-Quality-Factor Resonant Cavities
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Flying quality factors currently limiting helicopter nap of the earth maneuverability as identified by flight investigation
Flight tests with helicopters for studying manueverability
On the use of quality factors and fluence to dose rate conversion in human radiation exposures
It is shown that various combinations of numbers and factors arrive at estimates of dose and dose effectiveness from values of fluence; but as yet it has not been possible to use biological data with the same degree of precision to estimate the physical data. It would seem that the most reasonable way to use the human data that exist is to apply them as far as possible to the human animal as a whole.
Preliminary measurements of quality factors of monocrystals
High Q's were obtained with silicon and sapphire crystals on four points mechanical suspensions. Instrumentation was developed to observe the approach to thermal equilibrium at cryogenic temperatures and to study thermal noise level and fluctuations. High Q crystals with low thermal noise level are promising candidates as high stability time references.
Internal friction quality factor Q greater than or equal to 3100 achieved in lunar rock 70215,85
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Quality Factor and Microslipping of Fatigue Cracks in Thin Plates at Resonant Vibration
Resonant vibrations have been stimulated in thin metal plates using a non-contacting electromagnetic driver. A sinusoidal force was applied in a swept frequency fashion and the resulting surface displacements were monitored through the use of an acoustic microphone. It has been found that the presence of a fatigue crack in the sample causes a broadening of the second resonance peak. The Q factors of the resonance curves were determined and are directly correlated with the presence of fatigue cracks in the samples. The broadening of the curves is explained in terms of a microslipping at the crack face walls which reduces the amplitude of the resonant vibration by increasing the damping of the system. A comparison is made between the resonance characteristics of fatigue damaged and notched samples, where the stiffness of the two systems is nearly constant while the interaction between crack face walls is eliminated in the latter.
DEVELOPMENT OF A MECHANISTICALLY BASED MODEL FOR SPACE RADIATION RISK ASSESSMENT: A PRACTICAL APPROACH FOR CONTINUOUS IN SITU CHARACTERIZATION OF RADIATION QUALITY FACTORS IN SPACE
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