Determination of light efficiency of stilbene scintillators and their application to in-core spectrometry of fast neutrons

1982 ◽  
Vol 200 (2-3) ◽  
pp. 397-402 ◽  
Author(s):  
Dietmar Albert ◽  
Uta Brückner ◽  
Wolfgang Hansen ◽  
Wolfhard Vogel
Keyword(s):  
Fast Neutrons ◽  
Light Efficiency

scholarly journals Reactor rate modulation oscillation analysis with two detectors in Double Chooz

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
T. Abrahão ◽  
◽  
H. Almazan ◽  
J. C. dos Anjos ◽  
S. Appel ◽  
...  
Keyword(s):  
Reactor Power ◽  
Background Model ◽  
Fast Neutrons ◽  
Mixing Angle ◽  
Oscillation Analysis ◽  
Central Value ◽  
Double Chooz ◽  
Model Independent ◽  
Best Fit

Abstract A θ13 oscillation analysis based on the observed antineutrino rates at the Double Chooz far and near detectors for different reactor power conditions is presented. This approach provides a so far unique simultaneous determination of θ13 and the total background rates without relying on any assumptions on the specific background contributions. The analysis comprises 865 days of data collected in both detectors with at least one reactor in operation. The oscillation results are enhanced by the use of 24.06 days (12.74 days) of reactor-off data in the far (near) detector. The analysis considers the $$ {\overline{\nu}}_e $$ ν ¯ e interactions up to a visible energy of 8.5 MeV, using the events at higher energies to build a cosmogenic background model considering fast-neutrons interactions and 9Li decays. The background-model-independent determination of the mixing angle yields sin2(2θ13) = 0.094 ± 0.017, being the best-fit total background rates fully consistent with the cosmogenic background model. A second oscillation analysis is also performed constraining the total background rates to the cosmogenic background estimates. While the central value is not significantly modified due to the consistency between the reactor-off data and the background estimates, the addition of the background model reduces the uncertainty on θ13 to 0.015. Along with the oscillation results, the normalization of the anti-neutrino rate is measured with a precision of 0.86%, reducing the 1.43% uncertainty associated to the expectation.

A comparison of some absolute methods of measuring fast neutron flux

1950 ◽  
Vol 46 (2) ◽  
pp. 339-352 ◽  
Author(s):  
K. W. Allen ◽  
D. L. Livesey ◽  
D. H. Wilkinson
Keyword(s):  
Neutron Flux ◽  
Fast Neutron ◽  
Cross Sections ◽  
Absolute Measurement ◽  
Fast Neutrons ◽  
Fast Neutron Flux ◽  
Cavendish Laboratory ◽  
The Individual ◽  
Nuclear Processes

The absolute measurement of fast neutron flux presents several difficult problems. Few methods have yet been described in the literature, although the experimental techniques developed by several authors for the detection of fast neutrons (Baldinger, Huber and Staub(7), Barshall and Kanner(9), Amaldi, Bocciarelli, Ferretti and Trabacchi (3), Gray (19), Barshall and Battat(8)) may easily be adapted to this type of measurement. It is, however, most important to have available methods of measuring fast neutron flux to permit the determination of cross-sections for nuclear processes induced by fast neutrons, and several such methods have been developed in the Cavendish Laboratory in recent years. They are the subjects of separate papers (Bretscher and French (13), Kinsey, Cohen and Dainty (21), Allen (l), Allen and Wilkinson (2)). The main purpose of the present paper is to describe the results of experiments carried out to compare these methods in order to test the validity of the assumptions implicit in the individual methods.

Determination of soil density and water content by fast neutrons and gamma rays

1970 ◽  
Vol 6 (1) ◽  
pp. 223-229 ◽  
Author(s):  
J. C. Corey ◽  
A. R. Boulogne ◽  
J. H. Horton
Keyword(s):  
Water Content ◽  
Gamma Rays ◽  
Fast Neutrons ◽  
Soil Density

Determination of selenium by activation with fast neutrons

1969 ◽  
Vol 26 (4) ◽  
pp. 437-438
Author(s):  
V. T. Tustanovskii ◽  
U. Orifkhodzhaev
Keyword(s):  
Fast Neutrons

Determination of energy absorption in a mixed flux of fast neutrons and γ-rays by an ionization method

Atomic Energy ◽  
1961 ◽  
Vol 9 (2) ◽  
pp. 630-636
Author(s):  
Yu. I. Bregadze ◽  
B. M. Isaev ◽  
V. A. Kvasov
Keyword(s):  
Energy Absorption ◽  
Fast Neutrons ◽  
Ionization Method ◽  
Γ Rays

The potential and limitations of neutrons, electrons and X-rays for atomic resolution microscopy of unstained biological molecules

1995 ◽  
Vol 28 (2) ◽  
pp. 171-193 ◽  
Author(s):  
Richard Henderson
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Radiation Damage ◽  
Single Molecule ◽  
Biological Molecules ◽  
Atomic Resolution ◽  
Fast Neutrons ◽  
X Rays ◽  
Number Of Particles

SummaryRadiation damage is the main problem which prevents the determination of the structure of a single biological macromolecule at atomic resolution using any kind of microscopy. This is true whether neutrons, electrons or X-rays are used as the illumination. Forneutrons, the cross-section for nuclear capture and the associatedenergy deposition and radiation damage could be reduced by using samples that are fully deuterated and15N-labelled and by using fast neutrons, but single molecule biological microscopy is still not feasible. For naturally occurring biological material,electronsat present provide the most information for a given amount of radiation damage. Using phase contrast electron microscopy on biological molecules and macromolecular assemblies of ˜ 105molecular weight and above, there is in theory enough information present in the image to allow determination of the position and orientation of individual particles: the application of averaging methods can then be used to provide an atomic resolution structure. The images of approximately 10000 particles are required. Below 105molecular weight, some kind of crystal or other geometrically ordered aggregate is necessary to provide a sufficiently high combined molecular weight to allow for the alignment. In practice, the present quality of the best images still falls short of that attainable in theory and this means that a greater number of particles must be averaged and that the molecular weight limitation is somewhat larger than the predicted limit. ForX-rays, the amount of damage per useful elastic scattering event is several hundred times greater than for electrons at all wavelengths and energies and therefore the requirements on specimen size and number of particles are correspondingly larger. Because of the lack of sufficiently bright neutron sources in the foreseeable future, electron microscopy in practice provides the greatest potential for immediate progress.

Sign in / Sign up

Export Citation Format

Share Document