On the figure of merit in neutron time-of-flight measurements

Coceva, C.; Frisoni, M.; Magnani, M.; Mengoni, A.

doi:10.1016/s0168-9002(02)00903-8

Cited by 27 publications

(19 citation statements)

References 3 publications

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“…The resolution function of the n TOF facility has been simulated in the start-up phase by two different codes, FLUKA [13] and CAMOT [47], giving similar results within the available statistics. In the second phase of n TOF, the new spallation target assembly has been simulated again with FLUKA and also with MCNP for the two moderator configurations.…”

Section: The N Tof Resolution Functionmentioning

confidence: 99%

Performance of the neutron time-of-flight facility n_TOF at CERN

Guerrero¹,

Tsinganis²,

Berthoumieux³

et al. 2013

Eur. Phys. J. A

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226

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Abstract. The neutron time-of-flight facility n TOF features a white neutron source produced by spallation through 20 GeV/c protons impinging on a lead target. The facility, aiming primarily at the measurement of neutron-induced reaction cross sections, was operating at CERN between 2001 and 2004, and then underwent a major upgrade in 2008. This paper presents in detail all the characteristics of the new neutron beam in the currently available configurations, which correspond to two different collimation systems and two choices of neutron moderator. The characteristics discussed include the intensity and energy dependence of the neutron flux, the spatial profile of the beam, the in-beam background components and the energy resolution/broadening. The discussion of these features is based on dedicated measurements and Monte Carlo simulations, and includes estimations of the systematic uncertainties of the mentioned quantities.

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Section: The N Tof Resolution Functionmentioning

confidence: 99%

Performance of the neutron time-of-flight facility n_TOF at CERN

Guerrero¹,

Tsinganis²,

Berthoumieux³

et al. 2013

Eur. Phys. J. A

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226

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“…Regarding the associated uncertainties, in the case of the energy there is a source of uncertainty intrinsic to the facility which is its energy resolution. This was properly quantified by Coceva et al [42] and ranges between 5×10 −4 at 1 eV and 10 −3 around 500 eV. Thus, the table contains the energy uncertainty given by SAMMY except in those cases when it is smaller than the energy resolution of n_TOF, in which case the latter is given.…”

Section: -7mentioning

confidence: 98%

“…The SAMMY code includes in the fitting process all the experimental corrections associated with the sample (mainly self-shielding, multiple scattering, and Doppler broadening) and the facility (i.e., the time-of-flight to neutron energy distribution) referred to as resolution function [42].…”

Section: A Resonance Analysis Strategy With Sammymentioning

confidence: 99%

Measurement and resonance analysis of the237Np neutron capture cross section

Guerrero¹,

Cano‐Ott²,

Mendoza³

et al. 2012

Phys. Rev. C

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The neutron capture cross section of 237 Np was measured between 0.7 and 500 eV at the CERN n_TOF facility using the 4π BaF 2 Total Absorption Calorimeter. The experimental capture yield was extracted minimizing all the systematic uncertainties and was analyzed together with the most reliable transmission data available using the SAMMY code. The result is a complete set of individual as well as average resonance parameters [D 0 = 0.56(2) eV, γ = 40.9(18) meV, 10 4 S 0 = 0.98(6), R = 9.8 (6) (2002)]. The results indicate that a new evaluation combining the present capture data with reliable transmission data would allow reaching an accuracy better than 4%, in line with the uncertainty requirements of the nuclear data community for the design and operation of current and future nuclear devices.

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“…The resolution function was determined by means of Monte Carlo simulations [18] and has been validated experimentally by measuring narrow p-and d-wave capture resonances on a sample of nat Fe.…”

Section: A the N Tof Installationmentioning

confidence: 99%

New measurement of neutron capture resonances inBi209

Domingo‐Pardo¹,

Abbondanno²,

Aerts³

et al. 2006

Phys. Rev. C

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The neutron capture cross section of 209 Bi has been measured at the CERN n TOF facility by employing the pulse-height-weighting technique. Improvements over previous measurements are mainly because of an optimized detection system, which led to a practically negligible neutron sensitivity. Additional experimental sources of systematic error, such as the electronic threshold in the detectors, summing of γ -rays, internal electron conversion, and the isomeric state in bismuth, have been taken into account. γ -Ray absorption effects inside the sample have been corrected by employing a nonpolynomial weighting function. Because 209 Bi is the last stable isotope in the reaction path of the stellar s-process, the Maxwellian averaged capture cross section is important for the recycling of the reaction flow by α decays. In the relevant stellar range of thermal energies between kT = 5 and 8 keV our new capture rate is about 16% higher than the presently accepted value used for nucleosynthesis calculations. At this low temperature an important part of the heavy Pb-Bi isotopes are supposed to be synthesized by the s-process in the He shells of low mass, thermally pulsing asymptotic giant branch stars. With the improved set of cross sections we obtain an s-process fraction of 19±3% of the solar bismuth abundance, resulting in an r-process residual of 81±3%. The present (n, γ ) cross-section measurement is also of relevance for the design of accelerator driven systems based on a liquid metal Pb/Bi spallation target.

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On the figure of merit in neutron time-of-flight measurements

Cited by 27 publications

References 3 publications

Performance of the neutron time-of-flight facility n_TOF at CERN

Performance of the neutron time-of-flight facility n_TOF at CERN

Measurement and resonance analysis of the237Np neutron capture cross section

New measurement of neutron capture resonances inBi209

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