Distribution of Neutrons in the Atmosphere

Agnew, Harold M.; Bright, William C.; Froman, Darol K.

doi:10.1103/physrev.72.203

Cited by 30 publications

(2 citation statements)

References 18 publications

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“…Except for irradiation effects mentioned above, neutron irradiation is another important challenge that the devices must be faced in near-earth space and nuclear pollution environments [13][14][15]. Being neutrally charged, neutrons mainly destroy the material by introducing displacement damage, resulting in degeneration or even failure of the devices, which becomes a major threat to the long-term reliability of the device seriously.…”

Section: Introductionmentioning

confidence: 99%

Radiation damage and abnormal photoluminescence enhancement of multilayer MoS₂ under neutron irradiation

Xiong

Zhu

Wang

et al. 2021

J. Phys.: Condens. Matter

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In this work, neutron irradiation effects on the optical property of multilayer MoS2 have been investigated in depth. Our results display that the intensity of the photoluminescence (PL) spectra of MoS2 flakes tends to slightly decrease after exposed to neutron irradiation with low fluence of 4.0 × 108 n/cm2. An unexpected improvement of PL intensity, however, is observed when the irradiation fluence accumulates to 3.2 × 109 n/cm2. Combined with the experimental results and first-principles calculations, neutron irradiation damage effects of multilayer MoS2 are analyzed deeply. Sulfur vacancy (V S) is found to be responsible for the attenuation of the PL intensity as a major defect. In addition, our results reveal that the adsorbed hydroxyl groups (OH) and oxygen atoms (O) on the surface of MoS2 flakes not only promote the transition from trion excitons to neutral excitons, but also repair the V S in MoS2, both of which contribute to the enhancement of luminescence properties. The detailed evolution process of irradiation-induced defects is discussed to reveal the microscopic mechanism of the significantly difference in luminescence intensity of MoS2 under different irradiation stages. This work has great significance for evaluating the neutron radiation hardness of multilayer MoS2, which is helpful to enrich the fundamental research on neutron irradiation effects.

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Section: Introductionmentioning

confidence: 99%

Radiation damage and abnormal photoluminescence enhancement of multilayer MoS₂ under neutron irradiation

Xiong

Zhu

Wang

et al. 2021

J. Phys.: Condens. Matter

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show abstract

“…[1][2][3][4][5][6][7][8][9] The essential results thus far show an exponential increase of the neutron intensity as a function of altitude. Since neutrons in the cosmic radiation cannot be considered as primary particles because of their short lifetime, they must be produced in the atmosphere.…”

Section: Introductionmentioning

confidence: 99%

Upper Limit for the Time between Fission and the Emission of Neutrons

Snyder

Williams

1951

Phys. Rev.

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The Baker experiment to detect times of delay greater than ^5X10~9 sec for the emission of fission neutrons has been performed by observing the change in fission neutron counting rate when fission fragments are allowed to fly away from a neutron counter as compared to the counting rate when the fragments are kept in the vicinity of the counter. The fission neutrons were detected by observing proton recoils in a thickparaffin-lined proportional counter. The percent of neutrons delayed by a time of at least 8X 10~9 sec was found to be (3.6±2.8) percent.

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Die Intensitätsverteilung der Höhenstrahlungsneutronen in der Atmosphäre

Bagge

Fincke

1950

Annalen der Physik

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D i e IntensitGtsverteilung der Hiihenstrahlungsneutronen in der A fmosphareTon E r i c h B a g g e tind K a r l F i i i c k e (Mit 4 Abbildungen)ill a x 27. L a u e zum 70. Gebwtstag gewidmet InholtsiibersichtDie Inteiisitatsverteilung der Neutronen i n der Atmosphare wird nach einem Verfahren berechnet, bei dem der Brems-und DiffusionsprozeB dieser Partikel als ein Generationenproblem betrachtet wird. Die Neutronen eines vorgegebenen Euergiebereichs werden wie Teilchen einheitlicher Geschwindigkeit behandelt, denen man eine scheinbare Quellstarke und eineii ebensolchen Absorptionskoeffizient fur die Dauer ihrer Zugehorigkeit zu dieser Generation zuordnen kanii. Auf diese Weise 1al3t sich das Problem der riiumlichen Dichteverteilung der Neutronen in allen Energiebereichen von mehreren MeV his herab zur therniischeu Energie analytisch berechien. Es ergibt sich dabei, in Ubereinstimuiung mit neueren experimentellen Feststellungen von Yuan'), claB die Neutroiieiiiiiten~itat im Bereich von 20-22 kin Hohe ein Maximum besitzen niuB. Abweichende theoretiache und experimentelle Ergebiiisse werden in der Arbeit diskutiert. Fur die Energieverteilung der Neutronen zwischen Etllcrm und E -lo00 eV erhalt man naherungsweise die ~erfeilungsfuiiktioii dE E-'@. Die bisher vorliegenden Cadmiumund Bortlbsorptioiisinessungeri lassen sich auf Grund dieses Energiespektrums gut verstehen.

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Distribution of Neutrons in the Atmosphere

Cited by 30 publications

References 18 publications

Radiation damage and abnormal photoluminescence enhancement of multilayer MoS₂ under neutron irradiation

Radiation damage and abnormal photoluminescence enhancement of multilayer MoS₂ under neutron irradiation

Upper Limit for the Time between Fission and the Emission of Neutrons

Die Intensitätsverteilung der Höhenstrahlungsneutronen in der Atmosphäre

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Distribution of Neutrons in the Atmosphere

Cited by 30 publications

References 18 publications

Radiation damage and abnormal photoluminescence enhancement of multilayer MoS2 under neutron irradiation

Radiation damage and abnormal photoluminescence enhancement of multilayer MoS2 under neutron irradiation

Upper Limit for the Time between Fission and the Emission of Neutrons

Die Intensitätsverteilung der Höhenstrahlungsneutronen in der Atmosphäre

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Radiation damage and abnormal photoluminescence enhancement of multilayer MoS₂ under neutron irradiation

Radiation damage and abnormal photoluminescence enhancement of multilayer MoS₂ under neutron irradiation