Neutron interrogation of actinides with a 17MeV electron accelerator and first results from photon and neutron interrogation non-simultaneous measurements combination

2013 ◽  
Vol 312 ◽  
pp. 30-35 ◽  
Author(s):  
A. Sari ◽  
F. Carrel ◽  
F. Lainé ◽  
A. Lyoussi
Keyword(s):  
Electron Accelerator ◽  
Neutron Interrogation ◽  
Simultaneous Measurements ◽  
First Results

scholarly journals Technical Note: Evaluation of simultaneous measurements of mesospheric OH, HO<sub>2</sub>, and O<sub>3</sub> under photochemical equilibrium assumption: Statistical approach

2017 ◽  
Author(s):  
Mikhail Yu. Kulikov ◽  
Anton A. Nechaev ◽  
Mikhail V. Belikovich ◽  
Tatiana S. Ermakova ◽  
Alexander M. Feigin
Keyword(s):  
Transport Model ◽  
Full Range ◽  
Lower Thermosphere ◽  
Technical Note ◽  
Primary Data ◽  
Chemical Transport Model ◽  
Air Concentration ◽  
Simultaneous Measurements ◽  
First Results ◽  
One Year

Abstract. The Technical Note presents a statistically correct approach to evaluating simultaneous measurements of several atmospheric components under the assumption of photochemical equilibrium. We consider simultaneous measurements of OH, HO2, and O3 at the altitudes of the mesosphere as a specific example and their daytime photochemical equilibrium as an evaluating relationship. A simplified algebraic equation relating local concentrations of these components in the 50–100 km altitude range has been derived. The parameters of the equation are air temperature, air concentration, local zenith angle, and the rates of 9 reactions. We have performed one-year simulation of the mesosphere and lower thermosphere using a 3D chemical-transport model. The simulation shows that the discrepancy between the calculated evolution of the components and the equilibrium value given by the equation does not exceed 3–4 % in the full range of altitudes independent of season or latitude. We have developed the technique of statistic Bayesian evaluation of simultaneous measurements of OH, HO2 and O3 based on the equilibrium equation taking into account the measurement error. The first results of application of the technique to MLS/Aura data are presented in this Technical Note. It has been found that the satellite data of HO2 distribution regularly demonstrates essentially lower altitudes of mesospheric maximum of this component. This has also been confirmed by offline retrieval of HO2 from the MLS primary data.

scholarly journals Technical note: Evaluation of the simultaneous measurements of mesospheric OH, HO<sub>2</sub>, and O<sub>3</sub> under a photochemical equilibrium assumption – a statistical approach

2018 ◽  
Vol 18 (10) ◽  
pp. 7453-7471 ◽  
Author(s):  
Mikhail Y. Kulikov ◽  
Anton A. Nechaev ◽  
Mikhail V. Belikovich ◽  
Tatiana S. Ermakova ◽  
Alexander M. Feigin
Keyword(s):  
Statistical Approach ◽  
Transport Model ◽  
Full Range ◽  
Lower Thermosphere ◽  
Technical Note ◽  
Chemical Transport Model ◽  
Simultaneous Measurements ◽  
First Results ◽  
Mesosphere And Lower Thermosphere ◽  
One Year

Abstract. This Technical Note presents a statistical approach to evaluating simultaneous measurements of several atmospheric components under the assumption of photochemical equilibrium. We consider simultaneous measurements of OH, HO2, and O3 at the altitudes of the mesosphere as a specific example and their daytime photochemical equilibrium as an evaluating relationship. A simplified algebraic equation relating local concentrations of these components in the 50–100 km altitude range has been derived. The parameters of the equation are temperature, neutral density, local zenith angle, and the rates of eight reactions. We have performed a one-year simulation of the mesosphere and lower thermosphere using a 3-D chemical-transport model. The simulation shows that the discrepancy between the calculated evolution of the components and the equilibrium value given by the equation does not exceed 3–4 % in the full range of altitudes independent of season or latitude. We have developed a statistical Bayesian evaluation technique for simultaneous measurements of OH, HO2, and O3 based on the equilibrium equation taking into account the measurement error. The first results of the application of the technique to MLS/Aura data (Microwave Limb Sounder) are presented in this Technical Note. It has been found that the satellite data of the HO2 distribution regularly demonstrate lower altitudes of this component's mesospheric maximum. This has also been confirmed by model HO2 distributions and comparison with offline retrieval of HO2 from the daily zonal means MLS radiance.

scholarly journals A Simultaneous Five Colour Three Channel Photometer with Fiber Optics - Design and First Results

1984 ◽  
Vol 79 ◽  
pp. 665-671
Author(s):  
H. Barwig ◽  
R. Schoembs
Keyword(s):  
Fiber Optics ◽  
Comparison Star ◽  
High Time Resolution ◽  
Fast Variable ◽  
Simultaneous Measurements ◽  
First Results ◽  
Time Variations ◽  
Short Time ◽  
Optics Design ◽  
Calar Alto

Accurate photometry of fast variable objects requires simultaneous measurements of object, sky and comparison star with high time resolution. Additionally, if reliable colours of short time variations are of interest each light source has also to be measured simultaneously in several wavelength regions.The prototyp of a 3 channel 5 colour photometer fitting these requirements was constructed at the Universitats-Sternwarte Miinchen in 1983 and shall be described in the following. The development of this instrument was carried out in two steps: At first a 3 channel photometer had been designed for observations in integral light. It was successfully tested at Calar Alto Observatory (Mitt. Astron. Ges. 60, p. 474, 1983)

Discussion of the Oblique Rotator Model Cases Of 108 Aqr and x Serp.

1976 ◽  
Vol 32 ◽  
pp. 577-588
Author(s):  
C. Mégessier ◽  
V. Khokhlova ◽  
T. Ryabchikova
Keyword(s):  
Mathematical Formulation ◽  
The Other ◽  
Rotator Model ◽  
Oblique Rotator ◽  
First Results

My talk will be on the oblique rotator model which was first proposed by Stibbs (1950), and since received success and further developments. I shall present two different attempts at describing a star according to this model and the first results obtained in the framework of a Russian-French collaboration in order to test the precision of the two methods. The aim is to give the best possible representation of the element distributions on the Ap stellar surfaces. The first method is the mathematical formulation proposed by Deutsch (1958-1970) and applied by Deutsch (1958) to HD 125248, by Pyper (1969) to α2CVn and by Mégessier (1975) to 108 Aqr. The other one was proposed by Khokhlova (1974) and used by her group.

Meridional Circulation, Turbulence, and Diffusion Processes in Stars

1976 ◽  
Vol 32 ◽  
pp. 109-116 ◽  
Author(s):  
S. Vauclair
Keyword(s):  
Convection Zone ◽  
Diffusion Processes ◽  
Meridional Circulation ◽  
Diffusion Time ◽  
Work In Progress ◽  
First Results ◽  
Stellar Envelopes ◽  
And Diffusion ◽  
Turbulence And Diffusion ◽  
Hr Diagram

This paper gives the first results of a work in progress, in collaboration with G. Michaud and G. Vauclair. It is a first attempt to compute the effects of meridional circulation and turbulence on diffusion processes in stellar envelopes. Computations have been made for a 2 Mʘstar, which lies in the Am - δ Scuti region of the HR diagram.Let us recall that in Am stars diffusion cannot occur between the two outer convection zones, contrary to what was assumed by Watson (1970, 1971) and Smith (1971), since they are linked by overshooting (Latour, 1972; Toomre et al., 1975). But diffusion may occur at the bottom of the second convection zone. According to Vauclair et al. (1974), the second convection zone, due to He II ionization, disappears after a time equal to the helium diffusion time, and then diffusion may happen at the bottom of the first convection zone, so that the arguments by Watson and Smith are preserved.

Optical Properties of HVEM Accelerators

1975 ◽  
Vol 33 ◽  
pp. 180-181
Author(s):  
A. Strojnik ◽  
J.W. Scholl ◽  
V. Bevc
Keyword(s):  
Optical Properties ◽  
Electron Accelerator ◽  
Systematic Investigation ◽  
Electron Source ◽  
High Brightness ◽  
The Past ◽  
Wide Range ◽  
Optical Behavior

The electron accelerator, as inserted between the electron source (injector) and the imaging column of the HVEM, is usually a strong lens and should be optimized in order to ensure high brightness over a wide range of accelerating voltages and illuminating conditions. This is especially true in the case of the STEM where the brightness directly determines the highest resolution attainable. In the past, the optical behavior of accelerators was usually determined for a particular configuration. During the development of the accelerator for the Arizona 1 MEV STEM, systematic investigation was made of the major optical properties for a variety of electrode configurations, number of stages N, accelerating voltages, 1 and 10 MEV, and a range of injection voltages ϕ0 = 1, 3, 10, 30, 100, 300 kV).

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