Neutron transmission of single-crystal magnesium fluoride

2008 ◽  
Vol 41 (6) ◽  
pp. 1003-1008 ◽  
Author(s):  
J. G. Barker ◽  
D. F. R. Mildner ◽  
J. A. Rodriguez ◽  
P. Thiyagarajan
Keyword(s):  
Total Cross Section ◽  
Single Crystal ◽  
Thermal Neutron ◽  
Cross Section ◽  
Room Temperature ◽  
Magnesium Fluoride ◽  
Neutron Transmission ◽  
Epithermal Neutrons ◽  
Neutron Attenuation ◽  
Thermal Neutron Beam

The neutron attenuation through single-crystal magnesium fluoride has been measured as a function of wavelength at both room temperature and 77 K. These data confirm a total cross section that is lower than that of MgO for wavelengths greater than 0.2 nm. MgF2cooled to 77 K is a slightly better filter of epithermal neutrons than MgO for obtaining a thermal neutron beam.

Total Scattering Cross Section of Solids for Cold and Epithermal Neutrons

1984 ◽  
Vol 39 (12) ◽  
pp. 1160-1167 ◽  
Author(s):  
J. R. Granada
Keyword(s):  
Experimental Data ◽  
Solid State ◽  
Total Cross Section ◽  
Cross Section ◽  
Epithermal Neutron ◽  
Debye Model ◽  
Effect Of Temperature ◽  
Epithermal Neutrons ◽  
Total Scattering Cross Section ◽  
Asymptotic Forms

Simple expressions are given which accurately describe the total cross section of solids at cold and epithermal neutron energies. They are intended to provide a consistent procedure for the evaluation of solid state effects, which must be substracted from the experimental data when information is wanted on intrinsic nuclear properties. The formulae presented here are the asymptotic forms to which the full expressions reduce in those energy limits. A Debye model is adopted to describe the frequency spectrum of the solid. The present results are compared with some commonly used expressions as well as with the exact formalism. The effect of temperature is discussed and numerical calculations are presented for some cases.

Measurement of the total cross section of titanium with neutrons of 6–8 m/s

1982 ◽  
Vol 60 (5) ◽  
pp. 632-635 ◽  
Author(s):  
P. Gabriel ◽  
J. M. Robson
Keyword(s):  
Total Cross Section ◽  
Inelastic Scattering ◽  
Thermal Neutron ◽  
Cross Section ◽  
Cross Sections ◽  
Scattering Cross ◽  
Scattering Cross Sections ◽  
Inverse Velocity

The sum of the absorption, incoherent, and thermal inelastic scattering cross sections of natural titanium has been measured at 293 K for three neutron velocities in the range 6–8 m/s. They agree with values to be expected on the basis of an inverse velocity extrapolation from measurements near thermal neutron velocities.

Neutron Transmission of a Single-Crystal MgO Filter

1998 ◽  
Vol 31 (6) ◽  
pp. 841-844 ◽  
Author(s):  
P. Thiyagarajan ◽  
R. K. Crawford ◽  
D. F. R. Mildner
Keyword(s):  
Single Crystal ◽  
Liquid Nitrogen ◽  
Neutron Source ◽  
Room Temperature ◽  
Transmission Probability ◽  
Neutron Transmission ◽  
Absorption Probability ◽  
Cold Neutrons ◽  
Pulsed Neutron ◽  
Pulsed Neutron Source

The neutron transmission probability through a single-crystal MgO filter has been measured at both liquid-nitrogen (77 K) and room (300 K) temperatures, as a function of wavelength, using a pulsed neutron source. The data show that a cooled MgO filter is superior to room-temperature sapphire for both thermal and cold neutrons, principally because the absorption probability is reduced by a factor of three at long wavelengths.

Growth and Absorption Spectrum of Tm,Ho:BaY2F8 Crystal

2011 ◽  
Vol 335-336 ◽  
pp. 1025-1028 ◽  
Author(s):  
Fan Ming Zeng ◽  
Guang Tian Zou ◽  
Jing He Liu
Keyword(s):  
Absorption Spectrum ◽  
Single Crystal ◽  
Cross Section ◽  
Absorption Cross Section ◽  
Room Temperature ◽  
Laser Crystal ◽  
Rotation Speed ◽  
Absorption Cross ◽  
Technical Parameters ◽  
Cell Parameters

The Tm,Ho:BaY2F8 single crystal was successfully grown by the Cz method. The optimal technical parameters obtained are as follows: the pulling rate is 0.5—0.6mm/h; the rotation speed is 5—7rpm; the cooling rate is 10°C/h. The result of XRD curve shows that as-grown Tm,Ho:BaY2F8 laser crystal belongs to the monoclynicsystem and space group I41/a, the cell parameters calculated are: a = 0.69829 nm, b = 1.0519 nm, c = 0.42644 nm, β=99.676°, Z=2. Absorption spectra of Tm,Ho:BaY2F8 laser crystal at room temperature were measured and analysed, the absorption cross-section at 781nm calculated are 7.66×10-21cm-2.

Neutron/gamma radiation shielding characteristics and physical properties of (97.3–x)Pb–xCd–2.7Ag alloys for nuclear radiation applications

2021 ◽  
Author(s):  
Ahmed Mohamed Reda ◽  
A A El-Daly ◽  
E. A. Eid
Keyword(s):  
Thermal Neutron ◽  
Cross Section ◽  
Gamma Rays ◽  
Ternary Alloys ◽  
Nuclear Radiation ◽  
Fast Neutrons ◽  
Buildup Factor ◽  
Effective Electron ◽  
High Attenuation ◽  
Neutron Attenuation

Abstract In this work, the shielding performance of (97.3–x)Pb–xCd–2.7Ag (x=10, 18, and 30) ternary alloys against neutrons and gamma rays has been investigated. The microstructure, thermal and mechanical properties of the ternary alloys were examined. The total mass attenuation coefficients, μ⁄ρ, for prepared alloys were determined at 662, 1173, and 1332 keV photon energies using NaI (Tl) scintillation detector. The theoretical values of μ⁄ρ were calculated using WinXCom program depending on the mixture rule. The estimated values were compared with the measured values for all investigated alloys. Atomic cross-section, σa, electronic cross-section, σe, effective atomic number, Zeff, effective electron number, Neff, and GP fitting parameters (b, c, a, Xk, and d) were determined. The exposure buildup factor, EBF, have been also calculated. Fast neutron attenuation for the prepared samples have been investigated via the macroscopic effective removal cross-section (∑_R) calculation. Also, thermal neutron attenuation has been evaluated via neutron scattering calculator. The results show that the alloys containing 10 and 30% Cd compromise between superior tensile strength and Young modulus, while the pasty range, heat of fusion and ductility decreased with increasing Cd content. Moreover, the prepared ternary alloys have a high attenuation ability for gamma rays as the standard Pb. The increase of Cd ratio also significantly enhances the thermal neutron attenuation by amazing way along with the increase in the attenuation rate of fast neutrons.

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