arXiv subjects

S. M. Potin

Publications and source records attributed to S. M. Potin.

12 recordsLinked to original sources

arXiv2025

Cross-section of the ${^{\rm nat}\rm{Ni}}(γ,{\rm p} x\rm n)^{58}\rm{Co}$ reaction at the bremsstrahlung end-point energy of 35-94 MeV

The photoproduction of the $^{58}\rm{Co}$ nuclei on ${^{\rm nat}\rm{Ni}}$ was studied using the induced $γ$-activity method and off-line $γ$-ray spectrometric technique. The experiment was performed at the electron linear accelerator LUE-40 NSC KIPT, Ukraine. The total flux-averaged cross-section $\langle{σ(E_{\rm{γmax}})}\rangle$ for the ${^{\rm nat}\rm{Ni}}(γ,{\rm p} x\rm n)^{58}\rm{Co}$ reaction has been measured in the range of bremsstrahlung end-point energies $E_{\rm{γmax}}$ = 35-94 MeV. The obtained $\langle{σ(E_{\rm{γmax}})}\rangle$ were compared with theoretical estimates. The theoretical values of $\langle{σ(E_{\rm{γmax}})}\rangle_{\rm th}$ were calculated using the partial cross-sections $σ(E)$ from the TALYS1.96 code for different level density models and gamma strength functions.

nucl-ex↗

arXiv2025

Facility based on electron linac LUE-40 -- current state and main research directions

The paper describes the state of the installation based on the linear accelerator LUE-40 after restoration in 2023. Additional devices have been developed and created to conduct nuclear physics research. The main beam parameters are given. The electron energy range has been expanded and is currently 16-95 MeV with an average beam current of up to 6 $μ$A. The main areas of scientific research are described and the results are presented.

physics.acc-ph↗

arXiv2024

Cross-sections of photoneutron reaction $^{\rm nat}$Mo($γ,x$n)$^{\rm 93m}$Mo at the bremsstrahlung energy up to 95 MeV

The photoproduction of the $^{\rm 93m}$Mo nucleus on natural molybdenum was studied using the electron beam of the LUE-40 linac RDC "Accelerator" NSC KIPT. Measurements were performed using the activation method and off-line $γ$-ray spectrometric technique. For the $^{\rm nat}$Mo($γ,x$n)$^{\rm 93m}$Mo reaction the experimental flux-averaged cross-section <$σ(E_{\rm γmax})$>$_\rm m$ at the bremsstrahlung end-point energy range of 38--93 MeV was first time determined. The theoretical values of the yields $Y_{\rm m,g}(E_{\rm γmax})$ and flux-averaged cross-sections <$σ(E_{\rm γmax})$>$_{\rm m,g}$ for the $^{\rm nat}$Mo($γ,x$n)$^{\rm 93m,g}$Mo reactions were calculated using the cross-sections $σ(E_{\rm γ})$ from the TALYS1.96 code for different gamma strength functions and level density models. The comparison showed strong discrepancies between the experimental values and the theoretical results of <$σ(E_{\rm γmax})$>$_m$.

nucl-ex↗

arXiv2024

Photoproduction of the ${^{55-57}}$Co nuclei on ${^{\rm nat}}$Ni at the bremsstrahlung end-point energy of 35-94 MeV

Production of the ${^{55-57}}$Co nuclei on ${^{\rm nat}}$Ni in photonuclear reactions using bremsstrahlung gamma photon irradiation with end-point energy $E_{\rm{γmax}}$ between 35 and 94~MeV has been studied. The experiment was performed at the electron linear accelerator LUE-40 NSC KIPT using the methods of $γ$ activation and off-line $γ$-ray spectroscopy. The obtained experimental flux-averaged cross-sections $\langle{σ(E_{\rm{γmax}})}\rangle$ agree with the data found in literature. The theoretical flux-averaged cross-sections $\langle{σ(E_{\rm{γmax}})}\rangle_{\rm{th}}$ for the production of ${^{55-57}}$Co and ${^{55-57}}$Ni were estimated using the cross-section values $σ(E)$ from the TALYS1.95 code and bremsstrahlung spectra of gamma photons calculated by GEANT4.9.2. The experimental results for ${^{56,57}}$Co agree with the cumulative $\langle{σ(E_{\rm{γmax}})}\rangle_{\rm{th}}$. However theoretical prediction fails to reproduce the measured cross-sections for the production of ${^{55}}$Co.

nucl-ex↗

arXiv2023

Study the isomeric ratios in photonuclear experiments on the LUE-40 linac RDC "Accelerator" NSC KIPT

The results of the photoproduction of isomeric pairs from the (γ,xn) and (γ,pxn) reactions on nuclei from Zr up to Ta at the bremsstrahlung end-point energy range 30-100 MeV are systematized. Measurements were performed at the electron beam of the LUE-40 linac RDC "Accelerator" NSC KIPT using the activation method and off-line γ-ray spectrometric technique. The theoretical isomeric ratios IR for the nuclei-products of studied reactions were calculated using the cross-sections σ(E) from the TALYS1.95 code for six different level density models. The data from the international databases were additionally used to compare experimental results and theoretical predictions. The obtained results let us make conclusions about trends of values and energy dependence of IR in studied photonuclear reactions. Further directions of experimental research in the RDC "Accelerator" NSC KIPT are discussed.

nucl-ex↗

arXiv2023

Cross-section of the ${^{95\rm}\rm{Nb}}$ production on natural molybdenum at the bremsstrahlung end-point energy up to 95 MeV

The photoproduction of $^{95\rm m}$Nb on ${^{\rm nat}\rm{Mo}}$ was studied using the electron beam of the LUE-40 linac RDC "Accelerator" NSC KIPT. Measurements were performed using activation and off-line $γ$-ray spectrometric techniques. The experimental flux-averaged cross-section $\langle{σ(E_{\rm{γmax}})}\rangle_{\rm{m}}$ for the ${^{\rm nat}\rm{Mo}}(γ,x\rm np)^{95\rm m}$Nb reaction at the bremsstrahlung end-point energy range of 38--93 MeV has been first time obtained. The estimated values $\langle{σ(E_{\rm{γmax}})}\rangle_{\rm{g}}$ for the formation of $^{95}$Nb in the ground state and total cross-sections $\langle{σ(E_{\rm{γmax}})}\rangle_{\rm{tot}}$ for the studied reaction were determined. The theoretical values of the yields $Y_{\rm m,g,tot}(E_{\rm{γmax}})$ and flux-averaged cross-sections $\langle{σ(E_{\rm{γmax}})}\rangle_{\rm{m,g,tot}}$ for the ${^{\rm nat}\rm{Mo}}(γ,x\rm np)^{95\rm m,g,tot}$Nb reactions were calculated using the cross-sections $σ(E)$ from the TALYS1.95 code for six different level density models. The comparison showed a significant excess of the experimental results over the theoretical $\langle{σ(E_{\rm{γmax}})}\rangle_{\rm{m,g,tot}}$ values.

nucl-ex↗

arXiv2023

Production of ${^{180\rm{m}}}$Hf in photoproton reaction ${^{181}}$Ta$(γ,p)$ at energy $E_{\rm{γmax}}$ = 35-95 MeV

The production of the $^{180\rm{m}}\rm{Hf}$ nuclei in the photoproton reaction ${^{181}\rm{Ta}}(γ,p)$ was studied at end-point bremsstrahlung energies $E_{\rm{γmax}}$ = 35-95 MeV. The experiment was performed at the electron linear accelerator LUE-40 NSC KIPT with the use of the $γ$ activation and off-line $γ$-ray spectroscopy. The experimental values of the bremsstrahlung flux-averaged cross-sections $\langle{σ(E_{\rm{γmax}})}\rangle_{\rm{m}}$ for the ${^{181}\rm{Ta}}(γ,p)^{180\rm{m}}\rm{Hf}$ reaction were determined, and at $E_{\rm{γmax}} > 55$ MeV obtained for the first time. The measured values, also as the literature data, are significantly exceed the theoretical flux-averaged cross-sections $\langle{σ(E_{\rm{γmax}})}\rangle_{\rm{th}}$. The $\langle{σ(E_{\rm{γmax}})}\rangle_{\rm{th}}$ values were calculated using the cross-section $σ(E)$ computed with the TALYS1.95 code for six different level density models. A comparative analysis of the calculated total cross-sections for the reactions ${^{181}\rm{Ta}}(γ,p)^{180}\rm{Hf}$ and ${^{181}\rm{Ta}}(γ,n)^{180}\rm{Ta}$ was performed. It was shown that the photoproton $(γ,p)$ to photoneutron $(γ,n)$ strength ratio is consistent with the estimates based on the isospin selection rules and the value from the $(e,e'p)$ experiment.

nucl-ex↗

arXiv2023

Isomeric pair ${^{95\rm m,g}\rm{Nb}}$ in photonuclear reactions on $^{\rm nat}$Mo at end-point bremsstrahlung energy of 35-95 MeV

The ${^{\rm nat}\rm{Mo}}(γ,x\rm np)^{95\rm m,g}$Nb photonuclear reaction was studied using the electron beam from the NSC KIPT linear accelerator LUE-40. Experiment was performed using the activation and off-line $γ$-ray spectrometric technique. The experimental isomeric yield ratio $d(E_{\rm{γmax}}) = Y_{\rm m}(E_{\rm{γmax}}) / Y_{\rm g}(E_{\rm{γmax}})$ was determined for the reaction products $^{95\rm m,g}\rm{Nb}$ at the end-point bremsstrahlung energy $E_{\rm{γmax}}$ range of 35-95 MeV. The obtained values of $d(E_{\rm{γmax}})$ are in satisfactory agreement with the results of other authors and extend the range of previously known data. The theoretical values of the yields $Y_{\rm m,g}(E_{\rm{γmax}})$ and the isomeric yield ratio $d(E_{\rm{γmax}})$ for the isomeric pair $^{95\rm m,g}\rm{Nb}$ from the ${^{\rm nat}\rm{Mo}}(γ,x\rm np)$ reaction were calculated using the partial cross-sections $σ(E)$ from the TALYS1.95 code for six different level density models $LD$. The comparison showed a noticeable excess (more than 3.85 times) of the experimental isomeric yield ratio over all theoretical estimates. At the investigated range of $E_{\rm{γmax}}$ the theoretical dependence of $d(E_{\rm{γmax}})$ on energy was confirmed - the isomeric yield ratio smoothly decreases with increasing energy.

nucl-ex↗

arXiv2022

Photonuclear reactions cross-sections at energies up to 100 MeV for different experimental setups

In experiments on the electron linac LUE-40 of RDC "Accelerator" NSC KIPT, the flux-averaged cross-sections $\langle{σ(E_{\rm{γmax}})}\rangle_{\rm{exp}}$ of photonuclear reactions ${^{100}\rm{Mo}}(γ,n)^{99}\rm{Mo}$, ${^{27}\rm{Al}}(γ,x)^{24}\rm{Na}$, ${^{93}\rm{Nb}}(γ,n)^{92m}\rm{Nb}$, ${^{93}\rm{Nb}}(γ,3n)^{90}\rm{Nb}$, and ${^{181}\rm{Ta}}(γ,n)^{180g}\rm{Ta}$ were measured using the $γ$-activation technique. The theoretical flux-average cross-sections $\langle{σ(E_{\rm{γmax}})}\rangle_{\rm{th}}$ were computed using the partial cross-section $σ(E)$ values from the TALYS1.9-1.95 codes and bremsstrahlung $γ$-flux calculated using GEANT4.9.2. Two different experimental setups were used in the experiments: an aluminum electron absorber and a deflecting magnet to clean the bremsstrahlung $γ$-flux from electrons. A comparison of the flux-average cross-sections measured for two experimental setups was performed. The possibility of using the reactions ${^{100}\rm{Mo}}(γ,n)^{99}\rm{Mo}$, ${^{27}\rm{Al}}(γ,x)^{24}\rm{Na}$, ${^{93}\rm{Nb}}(γ,n)^{92m}\rm{Nb}$, ${^{93}\rm{Nb}}(γ,3n)^{90}\rm{Nb}$, and ${^{181}\rm{Ta}}(γ,n)^{180g}\rm{Ta}$ as monitors of the bremsstrahlung $γ$-flux for the energy range 30-100 MeV was investigated.

nucl-ex↗

arXiv2022

Photonuclear reactions ${^{65}\rm{Cu}}(γ,n)^{64}\rm{Cu}$ and ${^{63}\rm{Cu}}(γ,xn)^{63-x}\rm{Cu}$ cross-sections in the energy range $E_{\rm{γmax}}$ = 35-94 MeV

The bremsstrahlung flux-averaged cross-sections $\langle{σ(E_{\rm{γmax}})}\rangle$ for the photonuclear reactions ${^{65}\rm{Cu}}(γ,n)^{64}\rm{Cu}$, ${^{63}\rm{Cu}}(γ,n)^{62}\rm{Cu}$, ${^{63}\rm{Cu}}(γ,2n)^{61}\rm{Cu}$ and ${^{63}\rm{Cu}}(γ,3n)^{60}\rm{Cu}$ have been measured in the range of bremsstrahlung end-point energies $E_{\rm{γmax}}$ = 35-94 MeV. The experiments were performed with the electron beam from the NSC KIPT linear accelerator LUE-40 with the use of the activation and off-line $γ$-ray spectrometric technique. The calculation of the flux-average cross-sections $\langle{σ(E_{\rm{γmax}})}\rangle_{\rm{th}}$ was carried out using the cross-section $σ(E)$ values from the TALYS1.95 code with the default options. It is shown that the experimental average cross-sections for the reactions ${^{65}\rm{Cu}}(γ,n)^{64}\rm{Cu}$, ${^{63}\rm{Cu}}(γ,n)^{62}\rm{Cu}$, ${^{63}\rm{Cu}}(γ,2n)^{61}\rm{Cu}$ are systematically higher than the theoretical estimates in the TALYS1.95 code. The obtained $\langle{σ(E_{\rm{γmax}})}\rangle$ supplement the data of different laboratories for the case of reactions $(γ,n)$ and $(γ,2n)$. For the reaction ${^{63}\rm{Cu}}(γ,3n)^{60}\rm{Cu}$, the values of $\langle{σ(E_{\rm{γmax}})}\rangle$ were measured for the first time.

nucl-ex↗

arXiv2022

Photonuclear reactions $^{nat}$Ni($γ$,xn)$^{57}$Ni and $^{nat}$Ni($γ$,xn)$^{56}$Ni in the energy range E$_{γmax}$ = 35...94 MeV

The total bremsstrahlung flux-averaged cross-sections <$σ$(E$_{γmax}$)> for the photonuclear reactions $^{nat}$Ni($γ$,xn)$^{57}$Ni and $^{nat}$Ni($γ$,xn)$^{56}$Ni have been measured in the range of end-point energies E$_{γmax}$ = 35...94 MeV. The experiments were performed with the beam from the NSC KIPT electron linear accelerator LUE-40 with the use of the activation and off-line $γ$-ray spectrometric technique. The calculation of the flux-average cross-sections <$σ$(E$_{γmax}$)>$_{th}$ was carried out using the partial cross-section values $σ$(E) computed with the TALYS1.95 code and bremsstrahlung $γ$-flux calculated by GEANT4.9.2. The experimental results are compared with theoretical calculations and data from the literature. The obtained <$σ$(E$_{γmax}$)> values expand the energy range of previously known experimental data.

nucl-ex↗

arXiv2021

The impact of asteroid shapes and topographies on their reflectance spectroscopy

We report the comparison between unresolved reflectance spectroscopy of Solar System small bodies and laboratory measurements on reference surfaces. We measure the bidirectional reflectance spectroscopy of a powder of howardite and a sublimation residue composed of a Ceres analogue. The spectra are then inverted using the Hapke semi-empirical physical model and the MRTLS parametric model to be able to simulate the reflectance of the surfaces under any geometrical configuration needed. We note that both models enable an accurate rendering of the reflectance spectroscopy, but the MRTLS model adds less noise on the spectra compared to the Hapke model. Using the parameters resulting from the inversions, we simulate two spherical bodies and the small bodies (1)Ceres and (4)Vesta whose surfaces are homogeneously covered with the Ceres analogue and powder of howardite respectively. We simulate various scenarios of illumination and spectroscopic observations, spot-pointing and fly-bys, of these small bodies for phases angles between 6° and 135°. The unresolved reflectance spectroscopy of the simulated bodies is retrieved from the resulting images, and compared to the reflectance spectroscopy of the reference surface. Our results show that the photometric phase curves of the simulated bodies are different from the reference surfaces because of the variations of the local incidence and emergence angles due to the shape and topography of the surface. We observe the maximum differences at wide phase angles with the various simulated observations of (4)Vesta due to its high surface topography. Finally, we highlight the differences in the spectral parameters derived from the unresolved observations at 30° with laboratory measurements acquired under a single geometrical configuration.

astro-ph.EP↗