scholarly journals Initial Result of Neutron Emission Rate Analysis for Ion Cyclotron Range of Frequency Heated Deuterium Plasmas in LHD

2020 ◽  
Vol 15 (0) ◽  
pp. 1202088-1202088
Author(s):  
Ryosuke SEKI ◽  
Shuji KAMIO ◽  
Hiroshi KASAHARA ◽  
Kenji SAITO ◽  
Tetsuo SEKI ◽  
...  
Keyword(s):  
Emission Rate ◽  
Neutron Emission ◽  
Initial Result ◽  
Rate Analysis ◽  
Ion Cyclotron

scholarly journals Time dependent neutron emission rate analysis for neutral-beam-heated deuterium plasmas in a helical system and tokamaks

2018 ◽  
Vol 60 (9) ◽  
pp. 095010 ◽  
Author(s):  
Kunihiro Ogawa ◽  
Mitsutaka Isobe ◽  
Takeo Nishitani ◽  
Ryosuke Seki ◽  
Hideo Nuga ◽  
...  
Keyword(s):  
Emission Rate ◽  
Neutron Emission ◽  
Time Dependent ◽  
Neutral Beam ◽  
Rate Analysis

scholarly journals Study of ion cyclotron range of frequencies heating characteristics in deuterium plasma in the Large Helical Device

2021 ◽  
Vol 62 (1) ◽  
pp. 016004
Author(s):  
S. Kamio ◽  
K. Saito ◽  
R. Seki ◽  
H. Kasahara ◽  
M. Kanda ◽  
...  
Keyword(s):  
Simple Model ◽  
Emission Rate ◽  
Neutron Emission ◽  
Model Simulation ◽  
Second Harmonic ◽  
Hydrogen Ion ◽  
Deuterium Plasma ◽  
Ion Heating ◽  
Heating Efficiency ◽  
Ion Cyclotron

Abstract The characteristics of ion cyclotron range of frequencies (ICRF) minority ion heating with a hydrogen minority and deuterium majority plasma were studied by ICRF modulation injection experiments in the Large Helical Device (LHD). In recent experiments with deuterium plasma, no significant increase in the neutron emission rate due to ICRF second harmonic deuteron heating was observed. Therefore, in this study, the neutron emission rate was used to refer to the information regarding the thermal ion component. Like the results of the observations of the heating efficiencies at various minority proton ratios, the experimental results showed good agreement with the simple model simulation of ICRF wave absorption. During these experiments, the accelerated minority hydrogen ions were observed by neutral particle analyzers. The counting rates of the energetic particles were higher in the lines of sight passing through the helical ripple than across the magnetic axis, and the counting rate decreased as the minority hydrogen ion ratio increased. The dependence of the minority hydrogen ion ratio on the density of the energetic ions was consistent with the experimentally observed heating efficiencies and simulations. The heating efficiency of ICRF minority ion heating could be well explained by simple model simulation in the LHD deuterium experiment.

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

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.

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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