Measurement of activation cross sections of the proton induced nuclear reactions on palladium

Excitation functions of proton induced reactions on Pd are important for medical radioisotope production, for activation analysis, for development of low activation materials and other purposes. No experimental data exist in the literature for low and medium energy range protons. A detailed study of the excitation functions was performed up to 80 MeV proton energy by using the stacked foil irradiation technique and gamma-ray spectrometry. The irradiations were carried out at the external beam lines of the AVF cyclotron at the Tohoku University. Japan (80 and 70 MeV) and the CGR 560 cyclotron at the Vrije Universiteit Brussels (38, 29 and 17 MeV). The beam intensity, the incident energy and the energy degradation were controlled by a method based on flux constancy via normalization to the parallel measured excitation functions of ^natAl(p,x)^22,24Na and ^natCu(p,x)^56,58Co, ^62,65Zn monitor reactions. Excitation functions for direct and cumulative cross sections have been measured for the production of ^{105mg,106m,110m}Ag, ¹⁰¹Pd, ^101mRh and ⁹⁷Ru radionuclei. Calculations for the excitation functions using the Alice-IPPE code were performed with a view to estimate the weight of the different contributing reactions and to check the trend and the magnitude of the obtained experimental data.     

Excitation functions and energy spectra of proton induced reactions on56Fe and57Fe in the energy up to 30 MeV

The atmospheric particulate of industrialized cities had become a mixture of potentially toxic substances whose concentrations must be monitored to assess the pollution levels. Trace metals and elements are part of these pollutants and the knowledge of their total concentration in the air as well as their distribution in the different aerosol particle sizes is necessary to evaluate the pollution risk in terms of maximum present levels and long term exposure. In the present work, a preliminary part of a study initiated for monitoring the trace element levels present in the atmospheric particulate of the city of Milan (north Italy) and of its suburban areas is presented. More than 25 elements have been determined in Milan downtown along a period of three years and in different weather conditions. The granulometric distribution of selected potentially toxic elements (such as vanadium, lead, cadmium, nickel) has been also determined to evaluate their concentrations in different inhalable fractions (alveolar and bronchial — tracheal). Instrumental Neutron Activation Analysis (INAA) has been used for the determination of the great part of the elements while Graphite Furnace Atomic Absorption Spectroscopy (GF-AAS) has been employed for the determination of lead and, in some cases, for nickel, cadmium and copper.     

Photon and proton induced X-ray cross sections for some elements

The cross sections for the production of K and L shell x-rays in some elements by monoenergetic photons have been measured and the experimental values were compared with the theoretical values. Also, the K shell x-ray production cross sections have been measured for thin targets of some elements by protons over the energy range 1.5–3.0 MeV. The ionisation cross sections were calculated and compared with Johansson's empirical formula.     

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...     

Evaluation of proton induced reactions on 100Mo: New cross sections for production of 99 mTc and 99Mo

The use of the ⁹⁹Mo^99mTc generator in nuclear medicine is well established world wide. The production of the ⁹⁹Mo (T_1/2 = 66 h) parent as a fission product of ²³⁵U is largely based on the use of reactor technology. From the early 1990's accelerator based production methods to provide either direct produced ^99mTc or the parent ⁹⁹Mo, were studied and suggested as potential alternatives to the reactor based production of ⁹⁹Mo. A possible pathway for the charged particle production of ^99mTc and ⁹⁹Mo is irradiation of molybdenum metal with protons via the reaction ¹⁰⁰Mo(p,2n)^99mTc and ¹⁰⁰Mo(p,pn)⁹⁹Mo, respectively. The earlier published excitation functions show large differences in their maximum that result in large differences in the calculated yields. We therefore decided to study the excitation function for these proton-induced reactions. In this work the newly measured excitation functions as well as an evaluation of earlier measured data and a discussion of the observed disagreements are presented.     

Production cross sections of 14C in aluminum by nuclear spallation reactions

Although the estimation of ¹⁴C radioactivity is very important from a radiation safety viewpoint at high-intensity and high-energy accelerator facilities, it is very difficult, since there is little information concerning the production cross sections by high-energy nuclear reactions. In this work, the ¹⁴C production cross section was measured for the nuclear spallation reaction of aluminum with 12-GeV protons. The chemical separation method of ¹⁴C was also studied.     

Measurement of 14.7 MeV neutron cross sections for several isotopes

The (n,p), (n,), (n,2n), (n,np), and (n,n) reaction cross sections on²⁴Mg, 2²⁷Al,^28,29,30Si,^35,37Cl,⁴⁵Sc,⁴⁶Ti,⁵⁶Fe,^58,61Ni,⁹²Mo,¹⁰⁷Ag,^113,115In and¹⁹⁷Au target nuclei have been measured for E_n=14.73±0.05 MeV neutrons using the activation technique. The induced -ray activities of the irradiated samples and their monitor foils were measured using a HPGe detector. The cross sections are compared with existing results. The experimental uncertainties between 3% and 10% in most cases are generally smaller than those given by other authors.     

Investigation of the deuteron induced nuclear reaction cross sections on lutetium up to 50 MeV: review of production routes for 177Lu, 175Hf and 172Hf via charged particle activation

Journal of Radioanalytical and Nuclear Chemistry - Analytical techniques employing energetic beams are widely used for material characterization. In the present study, energy dispersive...     

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...     

Excitation functions of proton-induced nuclear reactions on124Xe: Production of123I

Highy enriched gaseous¹²⁴Xe /99.9%/ is used to perform instrumental measurements of excitation functions of the¹²⁴Xe/p, 2n/¹²³Cs and¹²⁴Xe/p, pn/¹²³Xe reactions up to the proton energy of 33 MeV. Differential and integral yields of¹²³I have also been determined /6.6 h after irradiation/.     

S K-shell ionization cross sections by protons of 0.8 to 3.0 MeV

Thick targets containing 2, 4, 8 and 50% by weight of S in a Li₂B₄O₇ matrix and pure S have been irradiated by protons in the energy range 0.8 to 3.0 MeV. The S K-shell ionization cross sections have been measured and compared to available theoretical and experimental data.     

Investigation of excitation functions of deuteron induced nuclear reactions on lead

Activation data of lead are of great importance due to the widespread applications of this element in various technological fields and to the well known adverse effects to biological systems. Use of high sensitivity radioanalytical techniques allows study of uptake, distribution and speciation. Cross sections of deuteron induced nuclear reactions on lead were measured up to 40 MeV using the standard stacked foil irradiation technique and high resolution gamma-ray spectrometry. Experimental cross sections and derived integral yields are reported for the ^natPb(d,xn)^{203,204,205,206,207}Bi, ^natPb(d,x)²⁰³Pb²⁰²Tl reactions. Only one set of experimental cross section data was found in the literature. The experimental data are analyzed and compared with the results of the theoretical model code ALICE-IPPE and with the experimental integral yield reported in the literature.     

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...     

Proton induced reactions of151Eu and153Eu up to Ep = 52MeV

Excitation functions for the proton induced reactions on¹⁵¹Eu and¹⁵³Eu have been measured by activation method up to E_p = 52MeV. The measurements are carried out on reactions to the residual nuclei—^{146,147,148,149,151,153}Gd and^{146,147,148,149}Eu. The measured excitation functions are discussed with the theory based on the statistical model of the compound nucleus.     

Experimental and theoretical cross section data of deuteron induced nuclear reactions on platinum

Journal of Radioanalytical and Nuclear Chemistry - Additional experimental activation cross sections for deuteron induced reactions on platinum were measured in the 35–49 MeV energy...     

Fission neutron spectrum averaged cross sections for threshold reactions on arsenic

Summary We have measured the cross sections, averaged over a ²³⁵U fission neutron spectrum, for the two high threshold reactions: ⁷⁵As(n,p)^75mGe and ⁷⁵As(n,2n)⁷⁴As. The measured averaged cross sections are 0.292±0.022 mb, referred to the 3.95±0.20 mb standard for the ²⁷Al(n,p)²⁷Mg averaged cross section, and 0.371±0.032 mb referred to the 111±3 mb standard for the ⁵⁸Ni(n,p)^58m+gCo averaged cross section, respectively. The measured averaged cross sections were also evaluated semi-empirically by numerically integrating experimental differential cross section data extracted for both reactions from the current literature. The calculations were performed for four different representations of the thermal-neutron-induced ²³⁵U fission neutron spectrum. The calculated cross sections, though depending on analytical representation of the flux, agree with the measured values within the estimated uncertainties.     

Quantum statistical study of O + O2 isotopic exchange reactions: cross sections and rate constants

Using a wave packet based statistical model, we compute cross sections and thermal rate constants for various isotopic variants of the O + O2 exchange reaction on a recently modified ab initio potential energy surface. The calculation predicts a highly excited rotational distribution and relatively cold vibrational distribution for the diatomic product. A small but important threshold effect was identified for the (16)O + 18O2 reaction, which is suggested to contribute to the experimentally observed negative temperature dependence of the rate ratio, k(18O + 16O2)/k(16O + 18O2). Despite reasonable agreement with quasiclassical trajectory results, however, the calculated thermal rate constants are smaller than experimental measurements by a factor from 2 to 5. The experimentally observed negative temperature dependence of the rate constants is not reproduced. Possible reasons for the theory-experiment discrepancies are discussed.     

Activation cross sections for some isotopes of Ti and Mo with 14.7 MeV neutrons

The (n,p) and (n,2n) reaction cross sections on natural Ti and Mo targets have been measured forE _n =14.73±0.05 MeV neutrons using the activation technique. The induced gamma-ray activities of the irradiated samples and their monitor foils were measured by using an HPGe detector. The cross sections were compared with previous results. The experimental uncertainties are between 3% and 8% in most cases.     

Determination of relative and absolute abundance of stable nitrogen isotopes by proton induced nuclear reactions

Thick-target yield of γ-rays emitted in the reactions¹⁴N(p,p′γ₁)¹⁴N and¹⁵N(p,αγ₁)¹²C were measured as a function of bombarding energy in order to select the conditions favoring the employment of these reactions in nitrogen isotopic analysis. The applicability of these reactions in the determination of relative as well as absolute nitrogen isotopic abundances was demonstrated at 4.3 MeV bombarding energy. Supported in part by the International Atomic Energy Agency, Vienna, Austria.