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

2007 ◽  
Vol 126 (1-4) ◽  
pp. 83-88 ◽  
Author(s):  
N. J. Roberts ◽  
L. N. Jones
Keyword(s):  
Emission Rate ◽  
Neutron Emission ◽  
Neutron Sources

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

1959 ◽  
Vol 37 (5) ◽  
pp. 550-556 ◽  
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.

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

1959 ◽  
Vol 37 (3) ◽  
pp. 256-262 ◽  
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.

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

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

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

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.

scholarly journals Central Deuteron Temperature Derived from Total Neutron Emission Rate in Electron Cyclotron Heated LHD Plasmas

2017 ◽  
Vol 12 (0) ◽  
pp. 1202036-1202036 ◽  
Author(s):  
Kunihiro OGAWA ◽  
Mitsutaka ISOBE ◽  
Takeo NISHITANI ◽  
Hiroki KAWASE ◽  
Neng PU ◽  
...  
Keyword(s):  
Emission Rate ◽  
Neutron Emission ◽  
Electron Cyclotron ◽  
Total Neutron
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