Production Cross Sections Of Radionuclides Research Articles

Production cross sections of radionuclides in the proton induced reactions on natural iron with the proton energy of 57 MeV

The production cross sections of 55,56,57Co, 52gFe, 52g,54Mn, 51Cr, and 48V from the natFe (p,x) reactions were measured using a proton energy of 57 MeV at the Korea Multi-purpose Accelerator Complex (KOMAC) in Gyeongju, Korea. The conventional stacked-foil activation method and offline γ-ray spectroscopy were used to determine the excitation functions of proton induced nuclear reactions on iron. The measured excitation functions were compared with experimental data in literature and theoretical data from the TENDL-2021 library. The present data show generally good agreement with other experimental data, but discrepancies were found between the present data and the excitation functions of the TENDL-2021 library in the investigated energy range, except for 56,57Co and 54Mn.

Short-lived radionuclide production cross sections calculated by the Liège intranuclear cascade model

In this paper, we calculate the cross sections for proton-induced reactions producing short-lived radionuclides like $^{7,10}\mathrm{Be}$, $^{26}\mathrm{Al}$, $^{53,54}\mathrm{Mn}$, etc., with the Li\`ege intranuclear cascade model (incl$++$). The results show that the incl model, when coupled with the proper deexcitation model, gives satisfactory results for most of the considered reactions. Generally, results for reactions with $(\mathrm{\ensuremath{\Delta}}N\ensuremath{-}\mathrm{\ensuremath{\Delta}}Z)$ equal to 0 or 1 are more likely to precisely match experimental data than those for reactions with larger or smaller $|\mathrm{\ensuremath{\Delta}}N\ensuremath{-}\mathrm{\ensuremath{\Delta}}Z|$. Our results can provide useful references for both the users and developers of incl and deexcitation models.

Cosmogenic radionuclide production modeling with Geant4: Experimental benchmarking and application to nuclear spectroscopy of asteroid (16) Psyche

Measurements of gamma-ray emissions from the decay of cosmogenic radionuclides provide an opportunity to characterize the elemental composition of a terrestrial planet or asteroid surface. We report on the development of a Geant4 application which models cosmogenic radionuclide production on metal-rich surfaces. The model was benchmarked using measurements of radionuclides produced during 1 GeV proton irradiation of a target made from the Campo del Cielo iron meteorite. The gamma-ray emitting radionuclides 58Co, 57Co, 56Co, 54Mn, 52Mn, 51Cr, 48V, 46Sc and 22Na were observed following the irradiation. Our model reproduced the measured radionuclide production rates to within a factor of 2.5 or better. All but two of the elements (54Mn, 46Sc) have a perfect model-to-data match within their measurement uncertainties. The benchmarked model was used to predict cosmogenic radionuclide production on a large (∼100-km radius) metal-rich asteroid. The results are relevant for planned gamma-ray measurements of the metallic asteroid (16) Psyche, which will be visited by the Psyche spacecraft in 2026. We found that galactic-proton-induced radionuclide decay is unlikely to be observed by the Psyche Gamma-Ray Spectrometer (GRS), however an intense solar proton event (>2 × 106 protons cm−2 over <5 days) will produce measurable quantities of radioisotopes. Measurements of these radioisotopes could provide an independent method of determining the Ni-to-Fe ratio of materials at Psyche’s surface. Such an analysis will require the use of radionuclide production cross sections to convert GRS-measured cosmogenic radionuclide decay rates to elemental composition information with the ∼10% precision required for planetary geochemical studies.

A method for radiological characterization based on fluence conversion coefficients

Radiological characterization of components in accelerator environments is often required to ensure adequate radiation protection during maintenance, transport and handling as well as for the selection of the proper disposal pathway. The relevant quantities are typical the weighted sums of specific activities with radionuclide-specific weighting coefficients. Traditional methods based on Monte Carlo simulations are radionuclide creation-event based or the particle fluences in the regions of interest are scored and then off-line weighted with radionuclide production cross sections. The presented method bases the radiological characterization on a set of fluence conversion coefficients. For a given irradiation profile and cool-down time, radionuclide production cross-sections, material composition and radionuclide-specific weighting coefficients, a set of particle type and energy dependent fluence conversion coefficients is computed. These fluence conversion coefficients can then be used in a Monte Carlo transport code to perform on-line weighting to directly obtain the desired radiological characterization, either by using built-in multiplier features such as in the PHITS code or by writing a dedicated user routine such as for the FLUKA code. The presented method has been validated against the standard event-based methods directly available in Monte Carlo transport codes.

Production cross-sections of radionuclides from α-induced reactions on natural copper up to 50 MeV

The excitation functions were measured for the natCu(α,x)66,67Ga,65Zn,57,58,60Co reactions in the energy range of 16.5 −50MeV. A conventional stacked-foil activation technique combined with HPGe γ-ray spectrometry was employed to determine cross-sections. The measured cross-sections were critically compared with relevant previous experimental data and also with the evaluated data in the TENDL-2014 library. Present results confirmed some of the previous experimental data, whereas only a partial agreement was found with the evaluated data. The measured data are useful for reducing the existing discrepancies in the literature, to improve the nuclear reaction model codes, and to enrich the experimental database towards various applications.

Measurements of proton-induced radionuclide production cross sections to evaluate cosmic-ray activation of tellurium

We have measured a large number of proton-induced radionuclide production cross sections from tellurium targets of natural isotopic composition at incident energies of 0.80, 1.4, and 23GeV. The results of these measurements are compared to semi-empirical calculations and the contribution of this cosmogenic activity to the background of the CUORE experiment, presently being realized, is evaluated.

Experimental evaluation of the nuclide production cross sections for 50-GeV protons in copper

A thin target composed of copper and aluminum foils was placed in the accelerator vacuum tube and irradiated with circulating 50-GeV protons. The number of protons that hit the target during the accelerator run was determined by the activation of the monitor aluminum foil, and the radionuclide activities in each foil were measured. A set of the radionuclide production cross sections in 50-GeV proton interactions with copper nuclei were evaluated.

Activation of Liquid Argon in the ATLAS Calorimeter by High-Energy Hadrons

Predictions of high-energy hadron activation of liquid argon in the calorimeter of A Thoroidal LHC ApparatuS (ATLAS) were carried out by folding particle flux spectra with the radionuclide production cross sections. Calculations were performed with a wide array of input data. Six sets of cross sections were folded with two sets of particle flux spectra, and the results were compared. The particle fluxes were obtained from simulations with the Monte Carlo radiation transport codes FLUKA and GCALOR. The cross-section sets were calculated according to the Rudstam and the Silberberg-Tsao formulas; taken from the Japanese Evaluated Nuclear Data Library (JENDL) and the Medium Energy Nuclear Data Library (MENDL); obtained from the Large Hadron Collider air activation studies; and compiled from various, predominantly experimental, sources.

Predicting induced radioactivity in a large high-energy physics apparatus: The example of the ATLAS experiment

Calculations of induced radioactivity in the ATLAS detector were performed in order to define its radioactive waste zoning. Two independent studies were carried out. The first was based on folding particle flux spectra obtained from the GCALOR code with the radionuclide production cross-sections. The second study was based on extensive calculations with the FLUKA code. This paper describes the two studies in detail; it presents the calculation methods and discusses their advantages and disadvantages. A comparison of their predictions is given. Finally, the paper discusses the designation of the ATLAS radioactive waste zoning on the basis of the combined knowledge gained from both studies.

Combining Semi-Classical and Quantum Mechanical Methodologies for Nuclear Cross-Section Calculations Between 1 MeV and 5 GeV

With a goal to develop a nuclear cross-section code usable over the wide energy range of 1 MeV to 5 GeV, one option is to combine intranuclear cascade, pre-equilibrium, and Hauser-Feshbach models in existing codes. However, the first two models are semi-classical while the third one is quantum mechanical, and combining them is not straightforward because the third model requires spin and parity distributions for all excited states that cannot be supplied by either one of the first two models. Approximations to overcome this difficulty are described in this paper. Success of this combined model will allow nuclear data evaluations for a large number of materials whose cross sections are needed in a wide range of applications, including the design, operation, and future upgrades of the SNS (1 GeV proton). The incident particles may be neutrons, protons, charged pions, or photons. Though only partially completed at this time, the new model compares well with experimental radionuclide production cross sections from thresholds to 2.6 GeV for proton-induced reactions on Fe.

Nuclide production by proton-induced reactions on elements (6 ≤ Z ≤ 29) in the energy range from 800 to 2600 MeV

In the course of a systematic investigation of proton-induced reactions for p energies between 800 and 2600 MeV, the target elements O, Mg, Al, Si, Ca, Ti, V, Mn, Fe, Co, Ni, Cu, Zr, Rh, Nb, Ba and Au were irradiated with 800 MeV protons at LAMPF/Los Alamos National Laboratory, and with 1200, 1600 and 2600 MeV protons at Laboratoire National Saturne/Saclay. The 1600 MeV irradiations covered in addition the target elements C, N, Rb, Sr, Y. The study was designed to measure production cross sections of radionuclides by γ-spectrometry and by accelerator mass spectrometry and of stable rare gas isotopes by conventional mass spectrometry. A detailed analysis of secondary particle fields was performed for targets of different thicknesses. Corrections for interferences by secondaries were made on the basis of secondary particle spectra as calculated by the code HET in the form of the HERMES code system and experimental and theoretical excitation functions of p- and n-induced reactions. Here, about 700 cross sections for the production of radionuclides from target elements Z ≤ 29 (Cu) by more than 200 reactions are presented. In addition, cross sections for the production of stable He and Ne isotopes from iron at a proton energy of 600 MeV are given. Together with earlier work of our group, there now exists a consistent set of excitation functions from threshold energies up to 2600 MeV. A comparison of the new data with earlier measurements from other authors exhibited a considerable lack of reliability for many of the earlier data. On the basis of the new data, the quality of existing semiempirical formulas for the calculation of spallation cross sections is discussed. In a more physical approach, the production of residual nuclides is calculated in the framework of an INC/E model using Monte Carlo techniques for energies between 100 MeV and 5 GeV and compared with the experimental results.

Protons as a Potential Source of Radioactivity in D-3He Reactors

This paper reports that a wide range of experimental radionuclide production cross sections has been collected for protons with energies similar to those protons produced in a D-{sup 3}He fusion reactor. Proton energy-dependent cross sections (E{sub p} {le} 14.7 MeV) were used along with the proton stopping data of Anderson and Ziegler to produce a proton-induced thick-target radionuclide activation yield library. The library is linked to a computer program that calculates proton-induced radioactivity. Another potential source of radioactivity considered is the activity induced by neutrons produced from proton interactions with reactor structure through (p,n) reactions. A computer program that evaluates the energy spectrum of these neutrons has been developed. The thick-target yield library and its associated programs have been used in an activation analysis study aimed at investigating the effect of proton-induced activity on the total level of radioactivity generated in Apollo-L2, a D-{sup 3}He tokamak fusion power reactor.