Eur. Phys. J. Plus (2025) 140: 367
https://doi.org/10.1140/epjp/s13360-025-06305-0

Regular Article

Modular apparatus for nuclear reactions spectroscopy (MARS): characterization and first application to determine $_{}^{12}$C($_{}^6$Li,$_{}^4$He)$_{}^{14}{\text{N}}^{g.s}$ nuclear reaction cross sections

¹ Departamento FAMN, Universidad de Sevilla, Apartado 1065, 41080, Sevilla, Spain
² Centro Nacional de Aceleradores, Universidad de Sevilla, Junta de Andalucía-CSIC, 41092, Sevilla, Spain
³ Institute for Transuranium Elements ITU, European Commission - Joint Research Centre, Box 2340, 76125, Karlsruhe, Germany

^a lgarrido2@us.es

Received: 23 February 2025
Accepted: 6 April 2025
Published online: 7 May 2025

Abstract

This work presents MARS (Modular apparatus for nuclear reactions spectroscopy) and its characterization prior to its first application to measure $_{}^6$Li+$_{}^{12}$C nuclear reactions. Measurements were performed at the 3 MV tandem accelerator of the CNA (National Accelerator Center), in Seville, Spain. The $_{}^6$Li projectiles were accelerated at energies around the $_{}^6$Li+$_{}^{12}$C Coulomb barrier ($V_B^{\text{cm}}\sim 3.0$ MeV - center of mass and $V_B^{\text{lab}}\sim 4.5$ MeV - laboratory frame). Using a $_{}^6{\text{Li}}^{2+}$ beam, we measured at 13 laboratory energies from 4.00 to 7.75 MeV. Thus, we present the excitation function of $_{}^{12}$C($_{}^6$Li,$_{}^4$He)$_{}^{14}{\text{N}}^{g.s.}$ reaction, at 2 backward angles ($110.0^{\circ }$ and $140.0^{\circ }$). The projectile dissociation, leading to this reaction, increases with the bombarding energies around the Coulomb barrier. This dissociation is favored at an optimum energy $E_b^{\text{op}}$$\ge$$V_B$ + $|Q_{\mathit{bu}}|$, where $V_B$ is the Coulomb barrier of the system, and $|Q_{\mathit{bu}}|$ is the module of Q-value for the $_{}^6$Li dissociation into $_{}^4$He+$_{}^2$H. This result corroborates a systematic analysis of weakly bound projectiles reacting on several targets [1].