Activation Measurement of the Doppler Effect for <sup>238</sup>U Capture and <sup>235</sup>U Fission in a Fast-Neutron Spectrum

Pflasterer, G.R.; Sher, R.

doi:10.13182/nse67-a18400

Cited by 8 publications

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“…The approximations 00 J in solving Eq. ( 4) are as follows, (1) Neutron flux if>~0(u) is independent of space and not affected by neutron absorption of the sample (narrow resonance approximation).…”

Section: Analysis and Discussionmentioning

confidence: 99%

“…After injection of a short burst of fast neutrons into a block of heavy moderator such as lead, the neutrons are slowed down by inelastic and elastic scattering processes, then attain an asymptotic energy distribution of the Gaussian type with the mean energy E, and the following simple relation holds between the slowing-down time t and mean neutron energy £< 9 J. E=c c )• (1) t+tel+tin • The last part of this paper defines all the symbols. The constants C, t, 1 and t;n are the characteristic values of the SDT spectrometer, and are determined from the experimental results<IOJ as follows:…”

Section: Principle Of Experimentsmentioning

confidence: 99%

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Measurements of Energy Dependent Doppler Factor for Uranium Dioxide Using a Lead Slowing-Down Time Spectrometer

Fujino

Takahashi

1977

Journal of Nuclear Science and Technology

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The energy dependent Doppler factor of resonance absorption in U0 2 was measured in the region of neutron energy between 1 eV and 10 keV using a U0 2 cylindrical sample and a lead slowing-down time spectrometer.The Doppler factor is herein defined as the ratio of neutron capture rate in the sample at the high temperatures T=450 and 30o•c to that at the low temperature T=20•C. The Doppler factor measured at T=450 and 300•C showed the maximum values of 1.225±0.044 and 1.186±0.040, respectively around the resonance of 66.3 eV. In the energy region above about 200 eV, the Doppler factor decreased with increasing neutron energy. In the energy region below about 70 e V except for region around the resonance of 6.68 eV, the Doppler factor decreased with increasing neutron energy.The energy dependent Doppler factors were calculated by the collision probability method and the resonance parameters of ENDF/B-lli. In the energy region of 1-454 eV, the calculation agreed with the experiment within the error of 5.4% which was not unreasonable when one considered the experimental errors of 3.1-4.7%. In the energy region of 454 eV-3 keV, the calculation was systematically 1-6.5% larger than the experiment, though the experimental errors were 2-3.63~ in this energy region.

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Section: Analysis and Discussionmentioning

confidence: 99%

Section: Principle Of Experimentsmentioning

confidence: 99%

Measurements of Energy Dependent Doppler Factor for Uranium Dioxide Using a Lead Slowing-Down Time Spectrometer

Fujino

Takahashi

1977

Journal of Nuclear Science and Technology

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“…The Doppler coefficient has been measured in small facilities, such as a critical assembly and an experimental reactor. [5][6][7][8] In these experiments, a sample of test material, whose Doppler coefficient was to be measured, was heated with electric heaters or laser beams so as to keep a predetermined temperature. The Doppler coefficient was evaluated from reactivity changes induced by temperature changes of the test sample.…”

Section: Introductionmentioning

confidence: 99%

Estimation of the Doppler Coefficient from a Lower Power Transient Observed in a Zero-Power Reactor Physics Test of a PWR (I)—Methodology—

Tsuji

Shimazu

Narabayashi

et al. 2009

Journal of Nuclear Science and Technology

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A method for estimating the Doppler coefficient from low power transient data that are measured in a routine experiment conducted in a zero-power reactor physics test of a PWR power plant has been developed. A dynamics identification model was introduced by considering two dynamics components for reactor kinetics and heat removal in the primary coolant loops. The dynamics identification method in the time domain was applied under consideration that the effect of reactivity feedback observed in the experiment was very small and measured transient data contained some intermittent intervals unavailable for dynamics identification. Unknown parameters, including the Doppler coefficient, contained in the dynamics model were determined stepwise through five estimation steps. In these steps, gamma ray noises were removed from the NIS signal, the reactivity feedback component was extracted from reactivity transient, and fuel temperature transient was determined in such way as to reproduce the observed low power transient in the digital simulation. In the final step, the Doppler coefficient was estimated from the extracted reactivity feedback component using the quantities evaluated in the preceding steps. The estimated value agreed well with the value evaluated with a core design code.

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A hybrid static/dynamic heating technique for the measurement of nuclear doppler effects

Russell

Bhattacharyya

Foell

1978

Nuclear Instruments and Methods

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Activation Measurement of the Doppler Effect for ²³⁸U Capture and ²³⁵U Fission in a Fast-Neutron Spectrum

Cited by 8 publications

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Measurements of Energy Dependent Doppler Factor for Uranium Dioxide Using a Lead Slowing-Down Time Spectrometer

Measurements of Energy Dependent Doppler Factor for Uranium Dioxide Using a Lead Slowing-Down Time Spectrometer

Estimation of the Doppler Coefficient from a Lower Power Transient Observed in a Zero-Power Reactor Physics Test of a PWR (I)—Methodology—

A hybrid static/dynamic heating technique for the measurement of nuclear doppler effects

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Activation Measurement of the Doppler Effect for 238U Capture and 235U Fission in a Fast-Neutron Spectrum

Cited by 8 publications

References 0 publications

Measurements of Energy Dependent Doppler Factor for Uranium Dioxide Using a Lead Slowing-Down Time Spectrometer

Measurements of Energy Dependent Doppler Factor for Uranium Dioxide Using a Lead Slowing-Down Time Spectrometer

Estimation of the Doppler Coefficient from a Lower Power Transient Observed in a Zero-Power Reactor Physics Test of a PWR (I)—Methodology—

A hybrid static/dynamic heating technique for the measurement of nuclear doppler effects

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Product

Resources

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Activation Measurement of the Doppler Effect for ²³⁸U Capture and ²³⁵U Fission in a Fast-Neutron Spectrum