Excitation functions of 93Nb(p,x) reactions from threshold to 42.5 MeV

Journal of Radioanalytical and Nuclear Chemistry - The excitation functions of 93Nb(p,x) reactions from their respective thresholds to 42.5 MeV were measured at the MC-50 cyclotron of...     

Cross section measurements for (n, p) and (n, 2n) reactions of rare-earth isotopes at neutron energies from 13.5 to 14.6 MeV

Cross sections for (n, p) and (n, 2n) reactions have been measured on some rare-earth isotopes at neutron energies of 13.5-14.6 MeV using activation technique. Data are reported for the following reactions:¹⁵⁰Nd(n, 2n) ¹⁴⁹Nd, ¹⁴⁸Nd(n, 2n) ¹⁴⁷Nd, ¹⁴²Nd(n, 2n) ¹⁴¹Nd, ¹⁶⁰Gd(n, 2n) ¹⁵⁹Gd, ¹⁵⁸Gd(n, p) ¹⁵⁸Eu, ¹⁴⁶Nd(n, p) ¹⁴⁶Pr, ¹⁴¹Pr(n, p) ¹⁴¹Ce and ¹³⁹La(n, p) ¹³⁹Ba. The neutron fluences are determined by the cross sections of ²⁷Al(n, a) ²⁴Na and ⁹³Nb(n, 2n) ^92mNb reactions. This revised version was published online in August 2006 with corrections to the Cover Date.     

Measurement of cross sections for the formation of 100gRh in natPd(p,x)100m,gRh reactions up to 42.61 MeV

Journal of Radioanalytical and Nuclear Chemistry - We measured the cross sections for the formation of the ground state nucleus 100gRh through natPd(p,x)100m,gRh reactions. The experiment was...     

Cross-sections for (n,2n), and (n,α) reactions on 55Mn isotope around neutron energy of 14 MeV

Cross sections for (n,2n) and (n,α) reactions on the Manganese isotope have been measured at the neutron energies of 14.1 and 14.7 MeV using activation method with the monitor reaction ²⁷Al(n, α)²⁴Na. This measurement was carried out by γ-detection using a coaxial HPGe detector. High-purity natural Manganese powder (99.9%) was used to produce the samples. The fast neutrons were produced by T(d, n)⁴He reaction. The results obtained are compared with the previous data.     

14.8 MeV neutron activation cross-sections for (n,p) and (n, α) reactions of some rare earth nuclides

The activation cross-sections for sixteen (n, p) and (n, α) reactions on rare earth nuclides were measured at 14.8 MeV neutron energy. A Ge(Li) detector was used for the radioactivity measurements. The measured cross-sections are compared with the semi-empirical predictions of LEVKOVSKII³ and BAYHURST and PRESTWOOD.¹⁶     

Proton (3 MeV) and copper (120 MeV) ion irradiation effects in low-density polyethylene (LDPE)

Low-density polyethylene (LDPE) was irradiated with proton (3 MeV) and copper (120 MeV) ions to analyze the induced modifications with respect to optical and structural properties. In the present investigation, the fluence for proton irradiation was varied up to 2×10¹⁵ protons cm⁻², while that for copper beam was kept in the range of 1×10¹ to 1×10¹³ ions cm⁻² to study the swift heavy ion-induced modifications in LDPE. Ultraviolet–visible (UV–vis), FTIR and X-ray diffraction (XRD) techniques were utilized to study the induced changes. The analysis of UV–vis absorption studies reveals that there is decrease of optical energy gap up to 43% on proton irradiation (at 2×10¹⁵ ions cm⁻²), whereas the copper beam (at 1×10¹³ ions cm⁻²) leads to a decrease of 51%. FTIR analysis indicated the presence of unsaturations due to vinyl end groups in the irradiated sample. The formation of OH and CO groups has also been observed. XRD analysis revealed that the semi-crystalline LDPE losses its crystallinity on swift ion irradiation. It was found that the proton beam (2×10¹⁵ ions cm⁻²) decreased the crystallite size by 23% whereas this decrease is of 31% in case of the copper ion-irradiated LDPE at 1×10¹³ ions cm⁻².     

Symmetry nonintegrability for extended K(m, n, p) equation

Journal of Mathematical Chemistry - In the present paper we study symmetries of extended K(m, n, p) equations and prove that the equations from this class have no generalized...     

(p, ρ, T) properties and apparent molar volumes Vϕ of CaCl2 in methanol at T = (298.15 to 398.15) K and pressure up to 40 MPa

The (p, ρ, T) properties and apparent molar volumes V_ϕ of CaCl₂ in methanol at T = (298.15 to 398.15) K, at pressures up to 40 MPa are reported, and apparent molar volumes have been evaluated. The experimental (p, ρ, T) values were described by an equation of state. The experiments were carried out at m = (0.10819, 0.28529, 0.65879 and 2.39344) mol · kg⁻¹ of calcium chloride.     

(p, ρ, T) Properties for n-butane in the temperature range from 280 K to 380 K at pressures up to 200 MPa

The (p, ρ, T) properties for n-butane in the compressed liquid phase were measured by means of a metal-bellows variable volumometer in the temperature range from 280 K to 380 K at pressures up to 200 MPa. The mole fraction purity of the n-butane used in the measurements was 0.9997. The expanded uncertainties (k = 2) in temperature, pressure, and density measurements have been estimated to be less than ±3 mK; 1.4 kPa (p ⩽ 7 MPa), 0.06% (7 MPa < p ⩽ 50 MPa), 0.1% (50 MPa < p ⩽ 150 MPa), and 0.2% (p > 150 MPa); and 0.09%, respectively. In the region above100 MPa at T = 280 K and T = 440 K, the uncertainty in density measurements increases from 0.09% to 0.13% and 0.22%, respectively. Eight (p, ρ, T) measurements at the same temperatures and pressures as the literature values have been conducted for comparisons. In addition, comparisons of the available equations of state with the present measurements are reported.     

(P, Vm, T) Measurements of (octane + 1-chlorohexane) at temperatures from 298.15 K to 328.15 K and at pressures up to 40 MPa

Densities were measured for the liquid octane and 1-chlorohexane, and for nine of their mixtures at four temperatures between 298.15 K and 328.15 K and at pressures up to 40 MPa. An apparatus for density measurements of liquids and liquid mixtures whose main part is a high-pressure vibrating-tube densimeter working in a static mode was used for the measurement. The density data were fitted to the Tait equation and the isothermal compressibilities were calculated with the aid of this equation. Excess molar volumes were also computed from the densities and fitted to the Redlich–Kister equation.     

The electrochemical reactions of copper(II) and copper(I) chloride in n,n-dimethylformamide

Polarographic, voltammetric and controlled-potential coulometric studies of copper(II) and copper(I) chloride in dimethylformamide are reported. The two chloride complexes of copper(II) are reduced in a total of three electrochemical steps to two copper(I)-chloride complexes and to copper(0). The two copper(I)-chloride species are reduced to copper(0) and oxidized to copper(II)-chloride complexes. The dissociation constant of the tetrachlorocuprate(II) complex has been polarographically estimated to be 10^-25.     

Densities,excess molar volume,isothermal compressibility,and isobaric expansivity of (dimethyl carbonate + n-hexane) systems at temperatures (293.15 to 313.15) K and pressures from 0.1 MPa up to 40 MPa

The densities of dimethyl carbonate, n-hexane and their mixtures were measured for 12 compositions at five different temperatures varying from (293.15 to 313.15) K and over the pressure range of (0.1 to 40) MPa. The densities of pure substances and their mixtures at atmospheric pressure were measured by a vibrating-tube densimeter. The densities at high pressures were measured by a variable-volume autoclave and precise analytical balance. The excess molar volume, isothermal compressibility, and isobaric expansivity were derived from the experimental densities.     

Extension of experimental activation cross-sections database of deuteron induced nuclear reactions on manganese up to 50 MeV

Journal of Radioanalytical and Nuclear Chemistry - In the frame of a systematic study of activation cross sections of deuteron induced reactions, experimental cross section data were measured on Mn...     

Excitation functions and yields of (d,n) and (d, 2n) reactions on natural molybdenum

The stacked foil technique was used for the determination of excitation functions of the reactions: ⁹²Mo(d, n)^93m,gTc;⁹⁸Mo(d, n)^99mTc;¹⁰⁰Mo(d, n)¹⁰⁰Mo(d, n)¹⁰¹Tc and ⁹⁴Mo(d, 2n)^94m,gTc by the irradiation of natural molybdenum by 13 MeV deuterons. The cummulative excitation functions for the production of^95m,gTc,⁹⁶Tc and^97mTc by means of the simultaneous (d, n) and (d, 2n) reactions were determined. The semiconductor γ- and X-ray spectrometry were used for the identification and for the determination of the absolute activity of technetium radioisotopes. Thick target yields and saturation production rates of^93m,gTc,^94m,gTc,^95m,gTc,⁹⁶Tc,^97mTc,^99mTc and¹⁰¹Tc have been evaluated for deuteron energies of 13.0 and 11.7 MeV.     

Average cross-sections for (n, α) and (n,p) reactions on titanium in a fission-type reactor spectrum

The average cross-section in a fission-type reactor spectrum was determined experimentally for the reactions:⁴⁶Ti(n,p)⁴⁶Sc,⁴⁷Ti(n,p)⁴⁷Sc,⁴⁸Ti(n,p)⁴⁸Ti(n,α)⁴⁵Ca and⁵⁰Ti(n,α)⁴⁷Ca. In order to obtain the (n,p) cross-sections, reactor irradiation of titanium was followed by measurement of the induced scandium activities with a Ge(Li) detector of calibrated detection efficiency. For this no chemical separations had to be carried out. For the (n,α) reactions, however, the induced calcium activities were separeted and purified by oxalate precipitation, after the bulk of the radioactivity had been removed by precipitation of titanium hydroxide. The⁴⁷Ca disintegration rate was determined in the same way as for the scandium isotopes, whereas for⁴⁵Ca liquid scintillation counting was carried out. The shape of the reactor spectrum was investigated by irradiating reference threshold detectors with different effective threshold energies. To correct for (n,γ) interferences, irradiations were carried out with and without cadmium shielding. On the basis of \(\bar \sigma _F = 0.64\) mb for the reaction²⁷Al(n,α)²⁴Na, the average cross-sections were as follows:⁴⁶Ti(n,p)⁴⁶Sc:10.5±0.4 mb;⁴⁷Ti(n,p)⁴⁷Sc: 16.3±0.6 mb;⁴⁸Ti(n,p)⁴⁸Sc:0.272±0.005 mb;⁴⁸Ti(n,α)⁴⁵Ca: 34μb;⁵⁰Ti(n,α)⁴⁷Ca: 8.1±0.3 μb.     

Measurements of (p, ρ, T) properties for isobutane in the temperature range from 280 K to 440 K at pressures up to 200 MPa

Measurements of (p, ρ, T) properties for isobutane in the compressed liquid phase have been obtained by means of a metal-bellows variable volumometer in the temperature range from 280 K to 440 K at pressures up to 200 MPa. The volume-fraction purity of isobutane used was 0.9999. The expanded uncertainties (k = 2) of temperature, pressure, and density measurements have been estimated to be less than 3 mK, 1.5 kPa (p ⩽ 7 MPa), 0.06% (7 MPa < p ⩽ 50 MPa), 0.1% (50 MPa < p ⩽ 150 MPa), and 0.2% (p > 150 MPa), and 0.11%, respectively. In region more than 100 MPa at 280 K and 440 K, the uncertainty in density measurements rise up to 0.15% and 0.23%, respectively. The differences of the present density values at the same temperature between two series of measurements, in which the sample fillings are different, are within the maximum deviation of 0.09% in density, which is enough lower than the expanded uncertainty in density. Eight (p, ρ, T) measurements at the same temperatures and pressures as the literature values have been conducted for comparison. In addition, vapour pressures were measured at T = (280, 300) K. Moreover, the comparisons of the available equations of state with the present measurements are reported.     

Measurement and correlation of the (p, ρ, T) relation of liquid n-heptane,n-nonane, 2,4-dichlorotoluene,and bromobenzene in the temperature range from (233.15 to 473.15) K at pressures up to 30 MPa for use as density reference liquids

Comprehensive (p, ρ, T) measurements on n-heptane, n-nonane, 2,4-dichlorotoluene, and bromobenzene were carried out in the homogeneous liquid phase for temperatures from (233.15 to 473.15) K at pressures up to 30 MPa. The measurements were performed by using an accurate single-sinker densimeter based on the Archimedes’ buoyancy principle. The total uncertainty of the measurements in density was estimated to be 0.02% (level of confidence 95%), except for densities at T ? 413.15 K, where the uncertainty was estimated to be 0.03%. Based on the experimental results, accurate correlation equations for the density of the four liquids have been established. Comparisons with previous results of other experimentalists and with values calculated from current equations of state are presented. The purpose of this work was to provide accurate correlation equations for the densities of the four selected liquids so that these liquids can be used as density reference liquids for the calibration of densimeters and, in particular, for the calibration of vibrating-tube densimeters.     

Activation cross-sections for some (n, 2n), (n,p) and (n, γ)-reactions

The average fission neutron cross-sections of the reactions²³³U(n, 2n)²³²U,⁶⁰Ni(n, p)⁶⁰Co and²⁷Al(n, p)²⁷Mg and the resonance integrals of the (n, γ)-reactions of the nuclides¹⁸¹Ta,¹⁷⁶Lu,¹⁷⁵Lu,⁶⁴Ni,⁵⁹Co and²⁶Mg have been determined by the activation method following the well-known conventions. The results verify some of the existing values and present data for hitherto unknown or poorly known reactions.