arXiv subjects

Sandipan Dasgupta

Publications and source records attributed to Sandipan Dasgupta.

6 recordsLinked to original sources

arXiv2026

Excitation function measurement of $^{144}$Sm($\alpha$,n) reaction at sub-Coulomb energies and detailed covariance analysis

The cross-section measurement of $^{144}$Sm($\alpha$,n)$^{147}$Gd (T$_{1/2}=$38.06(12) h) reaction has been performed at sub-Coulomb energies around 14$-$21 MeV ($V_{coul}\approx 21.8$ MeV) using the stacked foil activation technique. Irradiated targets were prepared from enriched (67\%) $^{144}$Sm$_2$O$_3$ powder using molecular deposition technique between thickness 280$-$350 $\mu$g/cm$^2$ on high purity Al backing. A detailed simulation has been carried out to address the energy uncertainty in the irradiated beam energy followed by a comprehensive discussion of various uncertainties in the form of covariance and correlation matrices. Finally the excitation functions are compared with the previously measured experimental data from literature and the theoretical predictions obtained using Hauser-Feshbach statistical model code.

nucl-ex↗

arXiv2026

Search for direct reaction products in 197Au+ 20Ne from 108 to 171 MeV projectile energy

The heavy ion induced nuclear reactions are of interest to nuclear physics community since long time. In this paper, we have reported production cross sections of 196Au, 198Au, 199Tl, 200Tl, 201Tl, which might be direct reaction (DIR) products, obtained through the interaction of 108-171 MeV 20Ne on natural gold target. The radioisotopes were identified and were quantitatively measured by off-line gamma spectrometry. We have also used two different simulation codes PACE4 and FLUKA (version 4-3.3). PACE4 did not predicted production of 196Au and 198Au, might be because PACE4 does not considers direct reactions, but predicted 199Tl, 200Tl, 201Tl. FLUKA grossly underpredicted production of all these radionuclides.

nucl-ex↗

arXiv2024

Proton induced reaction on $^{108}$Cd for astrophysical p-process studies

The proton capture cross-section of the least abundant proton-rich stable isotope of cadmium, $^{108}$Cd (abundance 0.89\%), has been measured near the Gamow window corresponding to a temperature range of 3-4 GK. The measurement of the $^{108}$Cd(p,$γ$)$^{109}$In reaction was carried out using the activation technique. The cross-section at the lowest energy point of 3T$_9$, E$_p$$^{lab}$= 2.28 MeV, has been reported for the first time. The astrophysical S-factor was measured in the energy range relevant to the astrophysical p-process, between E$_p$$^{cm}$= 2.29 and 6.79 MeV. The experimental results have been compared with theoretical predictions of Hauser-Feshbach statistical model calculations using TALYS-1.96. A calculated proton-optical potential was implemented to achieve better fitting, with different combinations of available nuclear level densities (NLDs) and $γ$-ray strength functions in TALYS-1.96. The calculations provided satisfactory agreement with the experimental results. The reaction rate was calculated using the calculated potential in TALYS-1.96 and compared with the values provided in the REACLIB database.

nucl-ex↗

arXiv2024

Fabrication of $^{108}$Cd target for the astrophysical p-process studies

The detailed process of preparing enriched $^{108}$Cd targets on mylar and copper backing using the vacuum evaporation technique is described. These targets were employed in an experiment to measure the proton capture cross-section at energies significantly below the Coulomb barrier, for the astrophysical p-process studies. Due to the low melting point and high vapor pressure of cadmium, some adjustments were implemented in the Telemark multipocket e-beam setup. The target thickness was determined through the measurement of alpha particle energy loss from a triple alpha source and also by RBS measurements. The thickness of the $^{108}$Cd films varies between 290 to 660 $μ$g/cm$^2$, with a non-uniformity of approximately 10$\%$. X-ray Photoelectron Spectroscopy (XPS) and X-ray Fluorescence (XRF) analyses were conducted to examine the presence of impurities and to assess surface morphology, phase, and chemical composition.

physics.ins-det↗

arXiv2024

Experimental study of $α$-induced reactions on $^{113}$In for astrophysical $p$-process

Neutron deficient nuclei from $^{74}$Se$-^{196}$Hg are thought to be produced by $γ$-induced reactions ($γ$,n), ($γ$,p) and ($γ,α$) processes. The relatively high abundance of $^{113}$In odd A $p$-nuclei has inspired to study its production processes. As reaction with $γ$-beam is difficult to perform in the laboratory, $γ$-induced reaction rate is calculated from the inverse reaction data employing reciprocity theorem. Stacked foil activation method was used to measure the $^{113}$In($α,γ$) and $^{113}$In($α$, n) reactions cross-section near the astrophysical energies. Theoretical statistical model calculations were performed with different nuclear input parameters and compared with the experimental results. An appropriate $α$-optical potential has been identified from the ($α,γ$) and ($α$, n) fitting, which provides the major source of uncertainty in the statistical model calculations. The other nuclear input parameters like level density, and $γ$-ray strength function were also constrained for theoretical calculations. $^{113}$In($α,γ$)$^{117}$Sb and $^{117}$Sb($α,γ$)$^{113}$In reaction rates were calculated using best-fitted input parameters.

nucl-ex↗

arXiv2024

Measurement of $^{144}$Sm(p,$γ$) cross-section at Gamow energies

The cross-section measurement of $^{144}$Sm(p, $γ$)$^{145}$Eu (T$_{1/2}=$5.93(4) days) reaction has been performed at proton energies around 2.6, 3.1, 3.7, 4.1, 4.2, 4.7, 5.1, 5.5, 5.9, 6.4, 6.8 MeV using the activation technique. These energies correspond to the Gamow window for 3, 4 GK and a partial portion for 2 GK. $^{144}$Sm has been chosen for the present study because of its significantly higher abundance compared to the other neighboring $p$-nuclides (Z $>$ 50). The astrophysical $S-$factor of this reaction has been measured for the first time at E$^{cm}_p=$ 2.57$\pm$0.13 MeV, $S-$ factor$=$2.542$\pm$1.152($\times$10$^{10}$) MeV-b. Cross-section data were compared with the previously measured experimental data from literature and the theoretical predictions obtained using Hauser-Feshbach statistical model codes TALYS 1.96 and NON-SMOKER. A satisfactory agreement between experimental data and theoretical results was observed. Molecular deposition technique was used to prepare the $^{144}$Sm targets having thickness between 100$-$350 $μ$g/cm$^2$ on Al backing. Obtained results were utilized to predict the reaction rates for $^{144}$Sm (p, $γ$) and $^{145}$Eu ($γ$, p) reactions using TALYS 1.96 and the reciprocity theorem.

nucl-ex↗