Definitions of thick target yields are reviewed
in relation to their documentation for the experimental nuclear
reaction data library (database).
Researchers reporting experimental thick target ...yields are urged
to define their yields clearly with an appropriate unit in order to compile
them in the experimental data library (EXFOR) in a consistent manner,
and also to properly utilise them for comparison with other
experimental and evaluated yields.
The neutron-induced fission cross sections were simultaneously evaluated for the JENDL-5 library for
233,235
U and
239,241
Pu from 10 keV to 200 MeV and for
238
U and
240
Pu from 100 keV to 200 MeV. ...Evaluation was performed by least-squares fitting of Schmittroth's roof function to the logarithms of the experimental cross sections and cross section ratios in the EXFOR library. A simultaneous evaluation code SOK was used with its extension to data in arbitrary unit. The outputs of the code were adopted as the evaluated cross sections without any further corrections. The newly obtained evaluated cross sections were compared with the evaluated cross sections in the JENDL-4.0 library and the IAEA Neutron Data Standards 2017. The evaluated cross sections were also validated against the californium-252 spontaneous fission neutron spectrum averaged cross sections,
(coupled thermal/fast uranium and boron carbide spherical assembly) neutron spectrum averaged cross sections, and small-sized LANL fast system criticalities. The changes in the obtained evaluated cross sections from those in the JENDL-4.0 library are within 4% (
241
Pu), 3% (
233
U,
240
Pu), or 2% (
235
U,
239
Pu). The newly evaluated
235
U,
238
U and
239
Pu cross sections agree with the IAEA Neutron Data Standards 2017 within 2% with some exceptions.
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The fourth version of the Japanese Evaluated Nuclear Data Library has been produced in cooperation with the Japanese Nuclear Data Committee. In the new library, much emphasis is placed on the ...improvements of fission product and minor actinoid data. Two nuclear model codes were developed in order to evaluate the cross sections of fission products and minor actinoids. Coupled-channel optical model parameters, which can be applied to wide mass and energy regions, were obtained for nuclear model calculations. Thermal cross sections of actinoids were carefully examined by considering experimental data or by the systematics of neighboring nuclei. Most of the fission cross sections were derived from experimental data. A simultaneous evaluation was performed for the fission cross sections of important uranium and plutonium isotopes above 10 keV. New evaluations were performed for the thirty fission-product nuclides that had not been contained in the previous library JENDL-3.3. The data for light elements and structural materials were partly reevaluated. Moreover, covariances were estimated mainly for actinoids. The new library was released as JENDL-4.0, and the data can be retrieved from the Web site of the JAEA Nuclear Data Center.
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The fourth version of the Japanese Evaluated Nuclear Data Library has been produced in cooperation with the Japanese Nuclear Data Committee. In the new library, much emphasis is placed on the ...improvements of fission product and minor actinoid data. Two nuclear model codes were developed in order to evaluate the cross sections of fission products and minor actinoids. Coupled-channel optical model parameters, which can be applied to wide mass and energy regions, were obtained for nuclear model calculations. Thermal cross sections of actinoids were carefully examined by considering experimental data or by the systematics of neighboring nuclei. Most of the fission cross sections were derived from experimental data. A simultaneous evaluation was performed for the fission cross sections of important uranium and plutonium isotopes above 10 keV. New evaluations were performed for the thirty fissionproduct nuclides that had not been contained in the previous library JENDL-3.3. The data for light elements and structural materials were partly reevaluated. Moreover, covariances were estimated mainly for actinoids. The new library was released as JENDL-4.0, and the data can be retrieved from the Web site of the JAEA Nuclear Data Center.
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•Deuteron-induced nuclear reactions on natural erbium were studied.•Stacked-foil activation technique and γ-ray spectroscopy was used.•Production parameters of 167mTm in NCA form is ...optimized.•Measured (d,p) data is important to improve the predicting capability of model codes.
Excitation functions for the natEr(d,x)163,165,166,167,168,170Tm and natEr(d,x)171Er nuclear reactions were measured from the respective thresholds up to 24 MeV by using a stacked-foil activation technique combined with HPGe γ-ray spectrometry. Measured data show a partial agreement when compared with the available literature data, theoretical data extracted from the TENDL-2019 library, and predicted data by the model code EMPIRE-3.2.2. Estimated physical thick target yields of the reaction products show close values to the directly measured ones available in the literature. The deduced yield curves indicate that a typical irradiation (Ed = 15 MeV, Id = 100 µA, tirr = 72 h) of enriched 167Er target by a low energy deuteron cyclotron is suitable to obtain more than a hundred GBq activity of 167Tm with negligible impurity from 168Tm. Measured data of 170Er(d,p)171Er reaction have great significance to improve the predicting capability of the model code.
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Results of new activation cross-section measurements for production of
178m1
Hf (T
1/2
= 4.0 s) and 179m1Hf (T
1/2
= 18.67 s) are presented for the following reactions:
178
Hf(n,n´)
178m1
Hf,
179
...Hf(n,2n)
178m1
Hf, 180Hf(n,3n)178m1Hf,
179
Hf(n,n´)
179m1
Hf, and
180
Hf(n,2n)
179m1
Hf. The irradiations were carried out at the 7-MV Van de Graaff accelerator at EC-JRC, Geel. Neutrons in the 1-3 MeV energy range were produced via the
3
H(p,n)
3
He reaction. Deuteron beam and a deuterium gas target were used to produce 5 and 6 MeV neutrons. For the production of quasi-monoenergetic neutrons between 16 and 19.5 MeV the 3H(d,n)4He reactions was employed. Both samples with natural composition and isotopic enrichment were employed to differentiate reactions leading to the same product. An automated pneumatic system was used for the sample irradiation, transport and radioactivity measurements. The radioactivity of the samples was determined by standard gamma-spectrometry using HPGe detector. The results obtained in the present work are compared with the data from other authors and TENDL-2017 evaluation.
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We measured the thermal cross sections of
71
Ga(n,
γ
)
72
Ga using an Am-Be neutron source having strength of 4 × 10
7
neutrons/sec using the two monitor reactions
197
Au(n,
γ
)
198
Au and
55
Mn(n,
γ
...)
56
Mn, and obtained 4.07±0.27 b and 3.97±0.31 b as the values measured relative to Au and Mn neutron captures, respectively. We constructed their covariance matrix by taking into account the correlation of parameters which are not independent in derivation of these two thermal cross sections
(e.g.,
Ga sample weight, decay data of
72
Ga, detector efficiency of
γ
-ray emitted from
72
Ga). The off-diagonal weighted mean of the two cross sections 4.04±0.27 b was derived from the two thermal cross sections and their covariance matrix.
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