Validation of capture reactions cross sections in Cf(s.f.) neutron field.

We have investigated following capture reactions: Au(n,g)Au, Cu(n,g)Cu, Sc(n,g)Sc, Ta(n,g)Ta, Ce(n,g)Ce, La(n,g)La, Yb(n,g)Yb, Mn(n,g)Mn, and Pr(n,g)Pr in a standard Cf(s.f.) neutron field.

Measurement of neutron spectra in spent fuel storage.

The neutron spectrum was measured at two locations in the spent fuel storage facility of the Temelín nuclear power plant. The measurement had two primary objectives: to map the neutron -γ field by quantifying the ambient dose equivalent H∗(10) and to identify methods that could improve the quality of the adjusted neutron spectrum using a Bonner Sphere Spectrometer (BSS). Three spectrometers were used: a BSS and two proton recoil spectrometers.

The spectrum-averaged cross section investigation of Sn(n,n')Sn and Zn(n,p)Cu reactions.

The spectrum averaged cross sections (SACS) in standard neutron field, e.g. Cf(s.

MEASUREMENT OF PROMPT GAMMAS OF INELASTIC SCATTERING IN D2O SPHERE USING AMBE SOURCE.

The inelastic neutron scattering is often followed by the emission of gamma photon. As the prompt gammas have a discrete level character they can be used for the identification of nuclides. Because of this fact, a good knowledge of photon production from inelastic scattering is important.

Spectrum averaged cross section measurements of lutetium using standard Cf neutron source.

The spectrum averaged cross section (SACS) in a standard neutron field is a preferable tool for cross section validation. The presented work uses only neutron standard, i.e.

Measurement of very high threshold reactions using Cf source.

Only neutron spectrum standard is Cf spontaneous fission neutron spectrum. However, the high energy tail of this spectrum is loaded with high uncertainty. To reduce this uncertainty, it is crucial to use validated cross sections with low uncertainty.

Validation of IRDFF-II library by means of Cf spectral averaged cross sections.

Spectrum-averaged cross sections (SACS) is an important quantity usable in validation of nuclear cross sections. Especially in case of dosimetrical reactions there is a request on precise validation. This paper presents SACS measured in the reference Cf(sf) neutron field for neutron dosimetry reactions to validate recently updated IRDFF-II library intended mainly for neutron metrology applications.

Application of Cf neutron source for precise nuclear data experiments.

Purpose of this paper is to provide extensive information helpful for anyone performing any experiment involving Cf neutron source and aiming for high precision experiments. The paper summarizes basic characteristics and fields of study using Cf neutron source. We show the basic characteristics of our source, precise geometry in MCNP6, isotopic content, distribution of the source in the encapsulation and possible use of encapsulation for Al(n,2n)Al reaction estimation and the way of handling of the Cf neutron source in our laboratory.

Validation of selected (n,2n) dosimetry reactions in IRDFF-1.05 library.

Spectrum-averaged cross sections (SACS) have been measured in the reference Cf(sf) neutron field for the following high-threshold (n,2n) neutron dosimetry reactions since they are especially important due to the high threshold which allows validation of upper parts of prompt fission neutron spectrum. This work includes 59Co(n,2n)58Co, 197Au(n,2n)196Au, Tm(n,2n)Tm, Mn(n,2n)Mn, Nb(n,2n)Nb and Y(n,2n)Y and for the Co(n,p)Fe threshold reactions. SACS were inferred from experimentally determined reaction rates by gamma spectrometry using a semiconductor high-purity germanium detector to measure irradiated samples.

The influence of core power distribution on neutron flux density behind a pressure vessel of a VVER-1000 Mock Up in LR-0 reactor.

The neutron flux distribution behind a reactor pressure vessel (RPV) is an important parameter that is monitored to determine neutron fluence in the RPV. Together with mechanical testing of surveillance specimens, these are the most important parts of in-service inspection programs that are essential for a realistic and reliable assessment of the RPV residual lifetime. The fast neutron fluence values are determined by a calculation.

Validation of nickel isotopes neutron cross sections using nickel spherical benchmark.

The fast leakage neutron spectra have been measured on spherical nickel benchmark assembly of diameter 50 cm. The Cf neutron source with approximate emission of 5.0·10 n/s was placed into the centre of the sphere.

On similarity of various reactor spectra and U prompt fission neutron spectrum.

A well-defined neutron spectrum is an essential tool not only for calibration and testing of neutron detectors used in dosimetry and spectroscopy but also for validation and verification of evaluated cross sections. A new evaluation of thermal-neutron induced U PFNS was performed by the International Atomic Energy Agency (IAEA) in the CIELO (Collaborative International Evaluated Library Organisation Project) project; new measurements of Spectral Averaged Cross sections averaged in the evaluated spectrum are to be obtained. In general, a neutron spectrum in the core is not identical to the pure fission one because fission neutrons undergo many scattering reactions, but it can be shown that PFNS and reactor spectra become undistinguishable from a certain energy boundary.

Disentangling the O cross section using light water and heavy water benchmark assemblies.

Fast neutron leakage spectra from the light and heavy water sphere of 30cm in diameter with neutron source in its centre were measured by a stilbene scintillation detector in the region of 1-10MeV in the distance of 85cm from the spheres surface. We use the light and heavy water to eliminate the effect of hydrogen. Cf with the approximate emission rate of 5.

Validation of differential cross sections by means of Cf spectral averaged cross sections.

The results of systematic evaluations of the spectrum-averaged cross section measurements performed in the spontaneous fission Cf neutron field are presented. The Following threshold reactions were investigated: Na(n,2n)Na, Fe(n,p)Mn, Fe(n,α) Cr, Al(n,p)Mg, Al(n,α)Na, F(n,2n)F, Zr(n,2n)Zr and Y(n,2n)Y. The spectrum-averaged cross sections for Na(n,2n)Na, Fe(n,α)Cr and Y(n,2n)Y reactions were measured for the first time.

Natural iron isotopes influence on the neutron transport.

As an iron is the main structural component of nuclear power plants as well as future fusion power plants, the validation of neutron incident data libraries of iron is a must. Presented paper fits into ongoing validation activities and presents measuring neutron leakage spectra in the 0.1-1.

On Fe neutron cross section importance in iron.

The presented paper aims to evaluate the importance of Fe XS in iron by means of measuring the reaction rates of the selected reactions on Fe and measuring a fast neutron leakage spectra from the iron sphere of 100cm in diameter by a stilbene scintillation detector with subsequent XS sensitivity analysis. The reactions involved in the study were Fe(n,p) and Fe(n,α). Measured neutron induced reaction rates in Fe are compared with calculated ones in different nuclear data libraries.

Measurement of reaction rates for different neutron induced reactions in Al.

The presented paper aims to compare various measured neutron induced reaction rates in Aluminium with computed ones in different nuclear data libraries. A Cf neutron source with emission rate of 9.53E8 n/s was used.