SF6− photodetachment near the adiabatic limit

2015 ◽  
Vol 17 (12) ◽  
pp. 7670-7675 ◽  
Author(s):  
I. Luzon ◽  
M. Nagler ◽  
O. Heber ◽  
D. Strasser
Keyword(s):  
Cross Section ◽  
High Sensitivity ◽  
Adiabatic Limit ◽  
Experimental Approaches ◽  
Photodetachment Cross Section ◽  
Experimental Values

High sensitivity photodetachment cross-section measurements suggest a SF6− adiabatic detachment energy of 1.7 ± 0.02 eV, significantly higher than previously recommended experimental values. Possible differences between the experimental approaches are discussed.

Experimental Studies Of Multilayer Glass Structures On Compression, Compression With Bending And Simple Bending

2019 ◽  
pp. 22-30
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Applied Load ◽  
Experimental Studies ◽  
Strength Properties ◽  
Research Topic ◽  
Normative Values ◽  
Laminated Glass ◽  
The Cross ◽  
Experimental Values

The work of multilayer glass structures for central and eccentric compression and bending are considered. The substantiation of the chosen research topic is made. The description and features of laminated glass for the structures investigated, their characteristics are presented. The analysis of the results obtained when testing for compression, compression with bending, simple bending of models of columns, beams, samples of laminated glass was made. Overview of the types and nature of destruction of the models are presented, diagrams of material operation are constructed, average values of the resistance of the cross-sections of samples are obtained, the table of destructive loads is generated. The need for development of a set of rules and guidelines for the design of glass structures, including laminated glass, for bearing elements, as well as standards for testing, rules for assessing the strength, stiffness, crack resistance and methods for determining the strength of control samples is emphasized. It is established that the strength properties of glass depend on the type of applied load and vary widely, and significantly lower than the corresponding normative values of the strength of heat-strengthened glass. The effect of the connecting polymeric material and manufacturing technology of laminated glass on the strength of the structure is also shown. The experimental values of the elastic modulus are different in different directions of the cross section and in the direction perpendicular to the glass layers are two times less than along the glass layers.

Ability of Naphthoquinondiazide Photoresists to Exothermic Decomposition

2020 ◽  
pp. 90-96
Author(s):  
A.N. Shushpanov ◽  
◽  
A.Ya. Vasin ◽  
V.M. Raykova ◽  
G.G. Gadzhiev ◽  
...  
Keyword(s):  
Convective Heat Exchange ◽  
Inert Atmosphere ◽  
Necessary Condition ◽  
Critical Temperatures ◽  
Good Convergence ◽  
Measuring Devices ◽  
Explosive Transformation ◽  
Exothermic Decomposition ◽  
Experimental Approaches ◽  
Experimental Values

The article considers two intermediate products of positive photoresists (1,2-naphthoquinonediazide-(2)-5-sulfonic acid of monosodium salt — Dye M and 1,2-naphthoquinonediazide-(2)-5-sulfochloride — Dye N2) from the standpoint of the tendency to explosive transformation. The experimental values of flash points determined on the OTP setup were 130 °C for Dye M and 95 °C for Dye N2. These values are close to the temperatures of the beginning of intensive exothermic decomposition (132 and 111 °C, respectively) obtained by thermogravimetric analysis. In addition, this analysis showed the presence of exothermic peaks in the studied samples both in the air and in an inert atmosphere of helium, which is a necessary condition for the manifestation of a tendency to explosive transformation. To confirm the possibility of explosive transformation, the flash points of substances were also determined by the calculation method according to the formula, which is a consequence of the problem of thermal explosion during convective heat exchange with the environment, and gave a result close to the experimental one (the values were 138 and 105 °C, respectively). For this calculation the following was used: the kinetic parameters determined by the Kissinger method, the values of the density of substances determined on an automatic pycnometer, as well as the values of the heat of explosive transformation obtained with the help of the Real computer thermodynamic program. The research results confirming the tendency of the investigated compounds to explosive transformation, as well as the critical temperatures, exceeding which is unacceptable, were transferred to the production of FGUP GNTs NIOPIK to create a safe technological process, safe storage and transportation conditions. Considering the accuracy of the measuring devices, the process temperature should not exceed 125 °C for Dye M and 90 °C for Dye N2. The conducted studies and calculations show that the computational and experimental approaches have good convergence, give values in a close temperature range, and increase the reliability of the obtained results.

scholarly journals The NUMEN Project: Toward New Experiments with High-Intensity Beams

Universe ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 72
Author(s):  
Clementina Agodi ◽  
Antonio D. Russo ◽  
Luciano Calabretta ◽  
Grazia D’Agostino ◽  
Francesco Cappuzzello ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
High Intensity ◽  
Particle Physics ◽  
Nuclear Physics ◽  
High Sensitivity ◽  
Experimental Information ◽  
Double Charge Exchange ◽  
Superconducting Cyclotron ◽  
Double Charge

The search for neutrinoless double-beta (0νββ) decay is currently a key topic in physics, due to its possible wide implications for nuclear physics, particle physics, and cosmology. The NUMEN project aims to provide experimental information on the nuclear matrix elements (NMEs) that are involved in the expression of 0νββ decay half-life by measuring the cross section of nuclear double-charge exchange (DCE) reactions. NUMEN has already demonstrated the feasibility of measuring these tiny cross sections for some nuclei of interest for the 0νββ using the superconducting cyclotron (CS) and the MAGNEX spectrometer at the Laboratori Nazionali del Sud (LNS.) Catania, Italy. However, since the DCE cross sections are very small and need to be measured with high sensitivity, the systematic exploration of all nuclei of interest requires major upgrade of the facility. R&D for technological tools has been completed. The realization of new radiation-tolerant detectors capable of sustaining high rates while preserving the requested resolution and sensitivity is underway, as well as the upgrade of the CS to deliver beams of higher intensity. Strategies to carry out DCE cross-section measurements with high-intensity beams were developed in order to achieve the challenging sensitivity requested to provide experimental constraints to 0νββ NMEs.

Experimental amplitude and frequency control of a self-excited microcantilever by linear and nonlinear feedback

2021 ◽  
Author(s):  
Eisuke Higuchi ◽  
Hiroshi Yabuno ◽  
Yasuyuki Yamamoto ◽  
Sohei Matsumoto
Keyword(s):  
Steady State ◽  
Frequency Control ◽  
High Sensitivity ◽  
High Viscosity ◽  
Measurement Methods ◽  
Nonlinear Feedback ◽  
Force Microscopy ◽  
Atomic Force ◽  
Excited Oscillation ◽  
Experimental Approaches

Abstract In recent years, measurement methods that use resonators as microcantilevers have attracted attention because of their high sensitivity, high accuracy, and rapid response time. They have been widely utilized in mass sensing, stiffness sensing, and atomic force microscopy (AFM), among other applications. In all these methods, it is essential to accurately detect shifts in the natural frequency of the resonator caused by an external force from a measured object or sample. Experimental approaches based on self-excited oscillation enable the detection of these shifts even when the resonator is immersed in a high-viscosity environment. In the present study, we experimentally and theoretically investigate the nonlinear characteristics of a microcantilever resonator and their control by nonlinear feedback. We show that the steady-state response amplitude and the corresponding response frequency can be controlled by cubic nonlinear velocity feedback and cubic nonlinear displacement feedback, respectively. Furthermore, the amplitude and frequency of the steady-state self-excited oscillation can be controlled separately. These results will expand application of measurement methods that use self-excited resonators.

scholarly journals The 7Be(p, ?)8B Cross Section at Low Energies

1980 ◽  
Vol 33 (2) ◽  
pp. 177 ◽  
Author(s):  
FC Barker
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Solar Neutrinos ◽  
Model Calculations ◽  
Spectroscopic Factors ◽  
Low Energies ◽  
Standard Values ◽  
Experimental Values ◽  
Parameter Values ◽  
Potential Parameters

The nonresonant part of the 7Be(p, )I)8B cross section at low energies is recalculated by means of a direct-capture potential model, using parameter values determined by fitting 7Li(n, n)7Li and 7Li(n, )I)8Li data. Standard values of the potential parameters and spectroscopic factors give values of the 7Li(n,)I) cross section that are too large. Modified values that fit the thermal-neutron capture cross section predict 7Be(p,)I) cross sections that are much less than the experimental values. Also, shell model calculations predict resonant 7Be(p,)I) cross sections that are smaller than the experimental values. It is suggested that the accepted experimental values of the 7Be(p, )I) cross section may be too large, perhaps due partly to an overlarge accepted value for the 7Li(d, p)8Li cross section, which has been used for normalization purposes. A decrease in the 7Be(p,)I) cross section would reduce the calculated detection rate of solar neutrinos and lessen the discrepancy with the measured value.

Regularities of changes in microhardness in the volume of EDT-69N binder cured at different temperatures

2020 ◽  
Vol 4 ◽  
pp. 65-71
Author(s):  
E.A. Veshkin ◽  
◽  
V.I. Postnov ◽  
V.V. Semenychev ◽  
E.V. Krasheninnikova ◽  
...  
Keyword(s):  
Cross Section ◽  
High Sensitivity ◽  
Sample Volume ◽  
Curing Temperature ◽  
Molding Temperature ◽  
Parabolic Law ◽  
Dimensionless Coefficient ◽  
Straight Line ◽  
Different Temperatures ◽  
The Difference

The change in the microhardness over the thickness of samples made of EDT-69N binder cured in vacuum and at atmospheric pressure at temperatures from 130 to 170°C was investigated. It was found that the change in microhardness along the thickness of the samples occurs according to the parabolic law, with the maximum values being achieved in the middle of the sample cross-section along the thickness. With an increase in the molding temperature, the microhardness in the middle section of the sample increases from 222 MPa at a molding temperature of 130°C to 410 MPa during molding at 170°C. At the critical molding temperature (170°C), the microhardness in all zones of the specimen cross section (subsurface, semi-average, and core) levels off, while the parabolic dependence degenerates into a straight line. It is shown that the method of scratching (sclerometry) demonstrated a sufficiently high sensitivity to the state of samples cured at different temperatures. With an increase in the molding temperature, the width of the sclerometric grooves decreases. At a critical molding temperature of 170°C, the groove width is stabilized and becomes constant throughout the sample thickness. To characterize the difference in the values of the microhardness of the cured binder in the sample volume, it is proposed to use a dimensionless “coefficient of volume anisotropy,” which can take a positive, negative or zero value. With an increase in the curing temperature of the binder and, accordingly, with an increase in the microhardness of the sample, the coefficient of volume anisotropy decreases, and when the samples are molded at the critical temperature, it turns to zero, which indicates the absence of anisotropy.

The determination of the cross sections for the reactions 27 Al( n , α ) and 56 Fe( n , p ) for 14 MeV neutrons by an absolute method

1966 ◽  
Vol 292 (1429) ◽  
pp. 180-192 ◽  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Standard Error ◽  
Particle Method ◽  
Systematic Errors ◽  
Aluminium Foil ◽  
The Mean ◽  
The Cross ◽  
Experimental Values

Measurements of the cross sections for the reactions 27 Al( n , α ) 24 Na and 56 Fe( n, p ) 56 Mn for neutrons of energy 13.5 ± 0.1 MeV have been made by a radioactivation method. The neutron flux was determined by a variant of the 'associated particle’ method, in which the α -particles produced concurrently with the neutrons from the D + T reaction were estimated in terms of the volume of helium which accumulated when they were brought to rest in an aluminium foil. Cross section values obtained at 13.5 MeV were: for 27 Al( n , α ): 118.1 ± 6.0 mb : for 56 Fe( n, p ): 106.7 ± 4.7 mb. The errors quoted include both the standard error on the mean of the experimental values and an estimate of possible residual systematic errors. The excitation functions for both reactions in the energy region 13.5 to 14.8 MeV have also been investigated, in order to provide secondary cross section values over this range of energies. At 14.8 MeV the values found were: 27 Al( n , α )103.6 ± 5.5 mb; 56 Fe( n, p )96.7 ± 4.5 mb.

Sign in / Sign up

Export Citation Format

Share Document