scholarly journals Multiplication of Fast Neutrons Source Flux by Using Deuterium-Helium-3 Plasma

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Mohammad Mahdavi ◽  
Maryam Shahbahrami
Keyword(s):  
Energy Loss ◽  
Neutron Flux ◽  
Thermal Neutron ◽  
Loss Rate ◽  
Thermal Neutron Flux ◽  
Fast Neutrons ◽  
Physical Parameters ◽  
Neutron Absorption ◽  
Absorption Length ◽  
Helium 3

The production of fast neutrons source is examined by using a thermal neutron flux inside plasma. In order to reach a favorable yield of fast neutrons flux, the parameters such as energy loss rate, reaction probability, and neutron absorption length are calculated. The nuclear conversion efficiency, , of thermal neutron to fast neutrons is obtained to be by calculating the physical parameters for the plasma designed.

scholarly journals Comparison of deep underground neutron flux measured with a helium-3 filled proportional counter and evaluated from element composition or isotopic ratio of 36Cl/Cl in granite rock

2011 ◽  
Vol 1 (1) ◽  
pp. 227-232
Author(s):  
T. Kubota ◽  
T. Ohta ◽  
Y. Mahara ◽  
A. Kudo
Keyword(s):  
Neutron Flux ◽  
Thermal Neutron ◽  
Elemental Composition ◽  
Proportional Counter ◽  
Thermal Neutron Flux ◽  
Isotopic Ratio ◽  
Deep Underground ◽  
Helium 3 ◽  
Good Agreement

Abstract The chlorine isotopic ratio and elemental composition of two granite cores collected in a deep underground tunnel has been measured; neutrons were detected using a helium-3-filled proportional counter placed in a borehole. The thermal neutron flux determined from the chlorine isotopic ratio from accelerator mass spectrometry is (3.8 ± 0.2) × 10−5 and that determined from the granite's elemental composition is (4.4 ± 0.3) × 10−5(cm−2 s−1). The results of in-situ measurements using the proportional counter yielded a thermal neutron flux value of (3.3 ± 0.1) × 10−5(cm−2 s−1). This good agreement among the results shows the validity of the neutron flux evaluation obtained from the elemental composition and/or the isotopic ratio of 36Cl/Cl. Further, it reveals that the neutron flux in the underground environment remains stable for at least one million years, i.e., the period over which chlorine-36 attains equilibrium.

scholarly journals Practical, visible wavelength nuclear-pumped laser

1993 ◽  
Vol 11 (3) ◽  
pp. 559-566 ◽  
Author(s):  
Y.R. Shaban ◽  
G.H. Miley
Keyword(s):  
Neutron Flux ◽  
Thermal Neutron ◽  
Thermal Neutron Flux ◽  
Visible Region ◽  
Laser Cavity ◽  
Pumping Power ◽  
University Of Illinois ◽  
Triga Reactor ◽  
Visible Wavelength ◽  
The University

A practical, visible nuclear-pumped laser (NPL) has been sought at the University of Illinois and other laboratories for a number of years. Yet, the results from successful visible NPLs to date have not been fully satisfactory, e.g., the threshold pumping power is too high for conventional applications. Progress in recent studies of 3He-Ne-H2 as a candidate NPL operating in the visible region at 585.3 nm on the 2P1,-1S2 Ne transition is described. We obtained lasing on the above transition for 3He-Ne-H2 concentrations of 1,140, 588, and 412 torr, respectively, with the laser cavity placed in the beamport of the University of Illinois TRIGA reactor. The threshold thermal neutron flux is 1014 n/cm2-s, corresponding to a threshold pumping power of 5 W/cm3.

Thermal neutron flux characterization at aircraft altitudes with the TinMan detector

2017 ◽  
Author(s):  
Suzanne Nowicki ◽  
Stephen Wender ◽  
Aaron Couture ◽  
Laura Dominik ◽  
Adam Warniment ◽  
...  
Keyword(s):  
Neutron Flux ◽  
Thermal Neutron ◽  
Thermal Neutron Flux ◽  
Neutron Flux Characterization

Determination of thermal neutron flux distribution at the rotary rack served for elemental concentration analysis using the k0-INAA method

2021 ◽  
Vol 10 (1) ◽  
pp. 11-20
Author(s):  
Tho Nguyen Thi ◽  
Anh Tran Tuan ◽  
Cuong Trinh Van ◽  
Doanh Ho Van ◽  
Duong Tran Quoc ◽  
...  
Keyword(s):  
Neutron Flux ◽  
Thermal Neutron ◽  
Flux Distribution ◽  
Thermal Neutron Flux ◽  
Epithermal Neutron ◽  
Epithermal Neutron Flux ◽  
Irradiation Position ◽  
Neutron Flux Distribution ◽  
Sample Irradiation

The accuracy of elements concentration determination using the k0-standardization method directly depends on irradiation and measurement parameters including Non-1/E epithermal neutron flux distribution shape α (ϕ epi ≈1/E1+α ) , thermal-to-epithermal neutron flux ratio f, efficiency ε, peak area… In the case of the irradiation position at the rotary rack of the Dalat Nuclear Research Reactor (DNRR), the difference of thermal neutron flux between the bottom (3.54x1012 n.cm-2.s-1) and the top (1.93x1012 n.cm-2.s-1) of the 15 cm aluminum container is up to 45%. Therefore, it is necessary to accurately determine above-mentioned parameters in the sample irradiation position. The present paper deals with the determination of the distribution of thermal neutron flux along the sample irradiation container by using 0.1% Au–Al wire activation technique. The thermal neutron flux was then used to calculate the concentration of elements in the Standard Reference Material 2711a and SMELS type III using k0-INAA method at different positions in the container. The obtained results with the neutron flux correction were found to be in good agreement with the certified values. In conclusion, the proposed technique can be applied for activation analyses without sandwiching flux monitors between samples during irradiations.

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