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Gledenov, Yu. M.; Nesvizhevsky, V. V.; Sedyshev, P.; Шульгина, Е. В.; Szalanski, P.; Vesna, V. A.

doi:10.1016/j.physletb.2017.03.035

Cited by 3 publications

(1 citation statement)

References 20 publications

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“…Neutron-flux fluctuations were compensated for as described above. Upon correcting for the degree of neutron polarization and the mean cosine of the harder-α emission angle over the angular acceptance, , the ILL measurement [46] yielded Combining the results of these two measurements, for the coefficient of P-odd asymmetry of α emission in the reaction we obtain Our measurements with a boron target were carried out using the same ionization-chamber detector as those with a lithium target discussed above and, apart from the target material, all experimental conditions were exactly the same. Therefore, the thorough analysis of background P-odd effects in various reactions induced by neutrons in construction materials carried out in [15] fully applies to our experiments with a boron target.…”

Section: Emission In the Reactionmentioning

confidence: 99%

Search and Measurement of P-Odd Asymmetry in the Emission of Secondary Particles Produced in Reactions of Polarized Thermal and Cold Neutrons with Light Nuclei

et al. 2021

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Investigation of spatial parity in reactions of polarized neutrons with light nuclei is an important topic in the framework of exploring the fundamental problem of understanding the manifestation of the weak interaction in nuclear reactions and for estimating the parameters of the weak nucleon-nucleon interaction. In this paper, the ongoing experimental program of highly sensitive and high-precision measurements of P-odd asymmetries in the reactions of polarized thermal and cold neutrons with lithium and boron nuclei is reviewed. Within this program, the coefficients of P-odd asymmetry of reaction products in the reactions induced by cold-and thermal-neutrons on the isotopes of light nuclei 6 Li and 10 B were measured with record-high sensitivity ~10 -8 as , and. For the first time ever, nonzero values were obtained for two of these asymmetries. Our data for tritium emission in the reaction and γ emission in the reaction agree with those of other experiments when interpreted within the cluster model, but rule out the so-called "best DDH values" of weak-interaction coupling constants. Interpreting the data on these reactions relying on "first principles" only would be highly desirable.

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Section: Emission In the Reactionmentioning

confidence: 99%

Search and Measurement of P-Odd Asymmetry in the Emission of Secondary Particles Produced in Reactions of Polarized Thermal and Cold Neutrons with Light Nuclei

et al. 2021

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A project of advanced solid-state neutron polarizer for PF1B instrument at Institut Laue-Langevin

Petukhov

Nesvizhevsky

Bigault

et al. 2019

Review of Scientific Instruments

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Among polarizers based on the neutron reflection from Super-Mirrors (SMs), solid-state neutron-optical devices have many advantages. The most relevant is the 5–10 times smaller size along the neutron beam direction compared to more traditional air-gap devices. An important condition for a good SM polarizer is the matching of the substrate SLD (Scattering Length Density) with the SM coating SLD for the spin-down component. For traditional Fe/Si SM on the Si substrate, this SLD step is positive when a neutron goes from the substrate to the SM, which leads to a significant degradation of the polarizer performance in the small Q region. This can be solved by replacing single-crystal Si substrates by single-crystal sapphire or quartz substrates. The latter shows a negative SLD step for the spin-down neutron polarization component at the interface with Fe and, therefore, avoid the total reflection regime in the small Q region. In order to optimize the polarizer performance, we formulate the concept of sapphire V-bender. We perform ray-tracing simulations of sapphire V-bender, compare results with those for traditional C-bender on Si, and study experimentally V-bender prototypes with different substrates. Our results show that the choice of substrate material, polarizer geometry, as well the strength and quality of magnetizing field have dramatic effect on the polarizer performance. In particular, we compare the performance of polarizer for the applied magnetic field strength of 50 mT and 300 mT. Only the large field strength (300 mT) provides an excellent agreement between the simulated and measured polarization values. For the double-reflection configuration, a record polarization >0.999 was obtained in the neutron wavelength band of 0.3–1.2 nm with only 1% decrease at 2 nm. Without any collimation, the polarization averaged over the full outgoing capture spectrum, 0.997, was found to be equal to the value obtained previously using only a double polarizer in the “crossed” (X-SM) geometry. These results are applied in a full-scale polarizer for the PF1B instrument.

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Realization of an advanced super-mirror solid-state neutron polarizer for the instrument PF1B at the Institut Laue–Langevin

Petoukhov

Nesvizhevsky

Bigault

et al. 2023

Review of Scientific Instruments

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In this last of a series of three papers on the development of an advanced solid-state neutron polarizer, we present the final construction of the polarizer and the results of its commissioning. The polarizer uses spin-selective reflection of neutrons by interfaces coated with polarizing super-mirrors. The polarizer is built entirely in-house for the PF1B cold neutron beam facility at the Institut Max von Laue–Paul Langevin (ILL). It has been installed in the PF1B casemate and tested under real conditions. The average transmission for the “good” spin component is measured to be >30%. The polarization averaged over the capture spectrum reaches a record value of P n ≈ 0.997 for the full angular divergence in the neutron beam, delivered by the H113 neutron guide, and the full wavelength band λ of 0.3–2.0 nm. This unprecedented performance is due to a series of innovations in the design and fabrication in the following domains: choice of the substrate material, super-mirror and anti-reflecting multilayer coatings, magnetizing field, and assembling process. The polarizer is used for user experiments at PF1B since the last reactor cycle in 2020.

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First observation of P-odd asymmetry of α -particle emission in theB10(n,α)Li

Cited by 3 publications

References 20 publications

Search and Measurement of P-Odd Asymmetry in the Emission of Secondary Particles Produced in Reactions of Polarized Thermal and Cold Neutrons with Light Nuclei

Search and Measurement of P-Odd Asymmetry in the Emission of Secondary Particles Produced in Reactions of Polarized Thermal and Cold Neutrons with Light Nuclei

A project of advanced solid-state neutron polarizer for PF1B instrument at Institut Laue-Langevin

Realization of an advanced super-mirror solid-state neutron polarizer for the instrument PF1B at the Institut Laue–Langevin

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