Measurements of Reaction Cross Sections for ¹²C, ²⁰Ne and ²⁷Al on heavy-mass targets

The reaction cross section (σ_R) for the atomic nucleus is closely related to the nuclear radius. The method to deduce nuclear radii from the measured σ_R is based on the Glauber model. The applicability of this method for light-mass nuclei (Z ≤20, A<50, such as ²⁷Al) has been well established with many precise σ_R data and the Glauber-type calculation in the energy range of 30~400 MeV/nucleon[1]. On the other hand, the applicability to medium- or heavy-mass nuclei has not yet been examined based on the experimental data. The theoretical study predicts the non-negligible contribution of the electromagnetic dissociation (EMD) (e.g. 6% of σ_R for the Pb + C system)[2]. In this study, we performed σ_R measurements for the medium and heavy mass regions where there is a lack of data. The σ_R for ¹²C, ²⁰Ne, and ²⁷Al on Fe and Pb targets were measured at the beam energies from 70 to 350 MeV/nucleon at the HIMAC (Heavy Ion Medical Accelerator in Chiba) facility. The obtained data were compared to the Glauber-type calculation, allowing us to evaluate the contribution of the EMD effect.

In the presentation, we will report the detailed results of our experiments and discuss the applicability of the Glauber-type calculation to heavier-mass nuclei considering the EMD effect.

References

[1] M. Takechi et al., Phys. Rev. C 79 (2009) 061601.

[2] W. Horiuchi et al., Phys. Rev. C 93 (2016) 044611.