Cross-section measurements of radiative proton-capture reactions inCd112at energies of astrophysical interest

Abstract

Reactions involving the group of nuclei commonly known as p nuclei are part of the nucleosynthetic mechanisms at astrophysical sites. The 113 In nucleus is such a case with several open questions regarding its origin at extreme stellar environments. In this work, the experimental study of the cross sections of the radiative proton-capture reaction 112 Cd(p, γ) 113 In is attempted for the first time at energies lying inside the Gamow window with an isotopically enriched 112 Cd target. Two different techniques, the in-beam γ-ray spectroscopy and the activation method, have been applied. The latter method is required to account for the presence of a low-lying 113 In isomer at 392 keV having a halflife of ≈ 100 min. From the cross sections, the astrophysical S factors and the isomeric ratios have been additionally deduced. The experimental results are compared to detailed Hauser-Feshbach theoretical calculations using TALYS, and discussed in terms of their significance to the optical model potential involved.

Radiative proton–capture reactions with 112,114Cd at astrophysically important energies

“…The experimental data presented in this work for the reaction 112 Cd(p, γ) 113 In are in excellent agreement with those of the earlier work of Psaltis et al [8], for the 3. extending the measurements above the neutron emission threshold for the reaction (E th = 3.397 MeV [6]), while still inside the Gamow energy window of astrophysical importance. At the same time, the experimental data for both reactions studied in this work are in good agreement with the theoretical predictions of the TALYS v1.95 code, with the TALYS Mod.…”

“…The full contributions of the isomeric transitions were determined by means of the activation technique, described in detail in Refs. [3,8,9]. Finally, the total cross sections were determined as:…”

“…Isotopically enriched (99.7%) 112 Cd and 114 Cd targets were used for the study of the radiative proton-capture reactions 112,114 Cd(p, γ) 113,115 In, using two different techniques, namely, in-beam γ-spectroscopy (described in detail in Refs. [3,7,8]) and the activation method [3,8,9], where the latter was deemed necessary to account for the presence of low-lying isomers in 113,115 In [6].…”

An Investigation of radiative proton-capture reactions in the Cd-In mass region

“…As an example, the odd-even 113 In nucleus, which is studied in the present work, is nowadays widely accepted that it is not a "pure" p nucleus, but has non-negligible contributions from the s and r processes (see discussions in refs. [16,17]).…”

“…Recent works by our group focusing on 107,109 Ag [18] and 112 Cd [16,19,20] proton-capture reactions have provided experimental input in this mass regime for both ground and isomeric states populated via the in-beam [21] and activation methods [22]. Precise measurements of cross sections in reactions of Ag, Cd and In isotopes, as well as other neighboring nuclei, around mass 100-120, using charged particle or photon probes, are necessary for reducing the experimental uncertainties and constraining the various pathways of p, r and s processes in this area of the nuclear chart [12,13,14].…”