ABSOLUTE STANDARDIZATION OF RADIOACTIVE NEUTRON SOURCES: II. THE USE OF THE F19(α, n)Na22 REACTION

K. W. Geiger

doi:10.1139/p59-062

ABSOLUTE STANDARDIZATION OF RADIOACTIVE NEUTRON SOURCES: II. THE USE OF THE F19(α, n)Na22 REACTION

Canadian Journal of Physics ◽

10.1139/p59-062 ◽

1959 ◽

Vol 37 (5) ◽

pp. 550-556 ◽

Cited By ~ 7

Author(s):

K. W. Geiger

Keyword(s):

Nuclear Reactions ◽

Emission Rate ◽

Neutron Emission ◽

National Research Council ◽

Neutron Output ◽

Neutron Sources ◽

Neutron Thermalization ◽

Γ Rays ◽

Absolute Standardization ◽

Good Agreement

Fluorine has only one stable isotope, F19. If neutrons are produced by the F19(α, n)Na22 reaction the neutron output can be calculated from the yield of the resulting radioactive Na22. The growth of Na22 (half-life, 2.58 years) has been measured in a neutron source consisting originally of 1.6 curies Po210 mixed with CaF2 powder. Since Na22 is a positron emitter, discrimination against γ-rays from Po210 and from nuclear reactions could be achieved by detecting the two positron annihilation quanta in coincidence. The Na22 growth has been followed over 20 months and is in agreement with the theoretical growth curve. Comparison with a calibrated Na22 source yielded a neutron emission rate of (10.70 ± 0.25) × 104 sec−1. This resulted in a neutron emission rate of (3.16 ± 0.10) × 106 sec−1 for the Ra-α-Be source of the National Research Council, in good agreement with (3.22 ± 0.05) × 106 sec−1 obtained by a neutron thermalization method.

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ABSOLUTE STANDARDIZATION OF RADIOACTIVE NEUTRON SOURCES: I. ACTIVATION OF MANGANESE BATH

Canadian Journal of Physics ◽

10.1139/p59-030 ◽

1959 ◽

Vol 37 (3) ◽

pp. 256-262 ◽

Cited By ~ 21

Author(s):

K. W. Geiger ◽

G. N. Whyte

Keyword(s):

Research Council ◽

Emission Rate ◽

Neutron Emission ◽

International Comparisons ◽

National Research Council ◽

National Bureau ◽

Neutron Sources ◽

Manganese Bath ◽

Absolute Standardization

The neutron emission rate of a Ra-α-Be source of the National Research Council has been measured by moderating the neutrons in manganese sulphate solution surrounding the source. Some of the thermal neutrons captured in the bath produce manganese-56, and the neutron emission rate is found from an absolute determination of the resulting activity. A number of corrections are discussed in detail. The value of (3.22 ± 0.05) × 106 neutrons per second found for the neutron emission rate shows satisfactory agreement with the results of our intercomparison with the primary neutron standard of the National Bureau of Standards, and allows a tie-in with a series of international comparisons of primary neutron sources.

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The content of 250Cf and 248Cm in 252Cf neutron sources and the effect on the neutron emission rate

Radiation Protection Dosimetry ◽

10.1093/rpd/ncm017 ◽

2007 ◽

Vol 126 (1-4) ◽

pp. 83-88 ◽

Cited By ~ 10

Author(s):

N. J. Roberts ◽

L. N. Jones

Keyword(s):

Emission Rate ◽

Neutron Emission ◽

Neutron Sources

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Characterization of the New Vertical Neutron Camera Designed for the Low Neutron Emission Rate Plasma in Large Helical Device

Plasma and Fusion Research ◽

10.1585/pfr.16.1402039 ◽

2021 ◽

Vol 16 (0) ◽

pp. 1402039-1402039

Author(s):

Siriyaporn SANGAROON ◽

Kunihiro OGAWA ◽

Mitsutaka ISOBE ◽

Yutaka FUJIWARA ◽

Hiroyuki YAMAGUCHI ◽

...

Keyword(s):

Emission Rate ◽

Neutron Emission

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Improvement in the calibration time of absolute emission rate of radioisotopic neutron sources using vanadyl sulfate bath

Applied Radiation and Isotopes ◽

10.1016/j.apradiso.2012.06.027 ◽

2012 ◽

Vol 70 (10) ◽

pp. 2446-2450 ◽

Cited By ~ 2

Author(s):

Rahim Khabaz

Keyword(s):

Emission Rate ◽

Vanadyl Sulfate ◽

Neutron Sources ◽

Sulfate Bath ◽

Calibration Time

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Pre-saddle and pre-scission neutron emission rates in heavy-ion induced fission of 16O +208Pb and 16O +209Bi systems

International Journal of Modern Physics E ◽

10.1142/s0218301319500137 ◽

2019 ◽

Vol 28 (03) ◽

pp. 1950013

Author(s):

Saeed Soheyli ◽

Morteza Khalil Khalili ◽

Ghazaaleh Ashrafi

Keyword(s):

Emission Rate ◽

Neutron Emission ◽

Nonlinear Behavior ◽

Heavy Ion ◽

Neutron Multiplicity ◽

Emission Rates ◽

Reaction Systems ◽

Initial Excitation ◽

Induced Fission ◽

First Time

Whereas there is a slight information on the pre-saddle neutron emission rate and neutron multiplicity, as well as it is impossible to separate the pre-saddle and saddle to scission neutron contributions experimentally, the theoretical studies of pre-saddle neutron emission rate and neutron multiplicity are of great importance. In the present work, the calculations of pre-saddle neutron multiplicity are performed using the analysis of fission fragment angular anisotropy data for [Formula: see text] and [Formula: see text] reaction systems. The obtained results show that the pre-saddle neutron multiplicity decreases by increasing the initial excitation energy and it has found to be characterized by a nonlinear behavior. Through the analysis of pre-saddle neutron multiplicity and pre-saddle transition time by means of the neutron clock method, the pre-saddle neutron emission rate is calculated for the first time. The findings of this study show that the pre-scission neutron emission rate is lower than the pre-saddle neutron emission rate.

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FORMATION OF 7Be IN NUCLEAR REACTIONS INDUCED BY 85-MeV PROTONS

Canadian Journal of Chemistry ◽

10.1139/v66-410 ◽

1966 ◽

Vol 44 (22) ◽

pp. 2749-2767 ◽

Cited By ~ 23

Author(s):

M. S. Lafleur ◽

N. T. Porile ◽

L. Yaffe

Keyword(s):

Cross Sections ◽

Nuclear Reactions ◽

Mev Protons ◽

Good Agreement

Cross sections were measured for the formation of 7Be in targets bombarded with 85-MeV protons. The variation of these cross sections with the mass and neutron-to-proton ratio of the target was investigated.Cross-section calculations were performed on the assumption that 7Be is emitted from the irradiated target as an evaporated particle. Calculated and measured cross sections were in good agreement for medium and heavy targets (A > 55). The calculation underestimated the production of' 7Be in light targets (27 < A < 55).

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SOME ASPECTS OF THE ELECTRON-BOSON INTERACTION AND OF THE ELECTRON-ELECTRON INTERACTION VIA BOSONS

Modern Physics Letters B ◽

10.1142/s0217984907012335 ◽

2007 ◽

Vol 21 (01) ◽

pp. 25-36 ◽

Cited By ~ 1

Author(s):

ANDREI DOLOCAN ◽

VOICU OCTAVIAN DOLOCAN ◽

VOICU DOLOCAN

Keyword(s):

Emission Rate ◽

Electron Gas ◽

Longitudinal Optical ◽

Standard Theory ◽

Electron Interaction ◽

Optical Phonons ◽

Polaron Energy ◽

Electron Photon ◽

Good Agreement ◽

Degenerate Electron Gas

By using a Hamiltonian of interaction between fermions via bosons1 we derive some properties of the electro-phonon and electron-photon interaction and also of the electron-electron interaction. We have obtained that in a degenerate electron gas there is an attraction between two electrons via acoustical phonons. Also, in certain conditions, there may be an attraction between two electrons via longitudinal optical phonons. Although our expressions for the polaron energy in both cases of the acoustical and longitudinal optical phonons are different from that obtained in the standard theory, their magnitudes are the same with these and they are in good agreement with experimental data. The total emission rate of an electron against a phonon system at absolute zero is directly proportional to the electron momentum. Also, an attraction between two electrons may appear via photons.

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