STOPPING POWER, EXPERIMENTAL TRENDS AND OPEN SUBJECTS, WITH FOCUS ON THE LOW TO INTERMEDIATE ENERGY REGION

C. C. MONTANARI

Congreso; 10th International Symposium on Swift Heavy Ions in Matter (SHIM) & 28th International Conference on Atomic Collisions in Solids (ICACS); 2018

www.shim-icacs2018.org

We will discuss the present, trends and vacancies in the experimental electronic-stoppingpower based on the publications of the last fifteen years and on my work for the stoppingdatabase of the International Atomic Energy Agency (IAEA) [1,2]. This collection of data,figures, codes and statistics is the legacy of Helmut Paul, and covers since the earlymeasurements in the 30s up to the present, being updated with the new publishedmeasurements from different laboratories worldwide.In the last decades this field had a revival due to the demand of accurate data formultipurpose-simulations, mainly for materials of technological and medical interest, i.e.oxides, polymers, water and biological targets (see figure 1). The possibilities and precisionof current experimental techniques have also contributed to advances in the low-energyelectronic stopping, raising new questions on the expected linear dependence with thevelocity, the density of electrons involved, and the behavior of oxides and insulators [3,4]. Inthis area we proposed in [5] a non-perturbative binary-collisional model for the energy lossof protons and antiprotons in a free-electron-gas based on a central screened-potential thatverifies the cusp condition for the induced density. We will show results for canonical targetssuch as Li, C, Ni, Be, Ti, Si, Al, Cr, Pb and Ge (see figure 2), and also for targets with recent experimental data as Ta and Mo, in an extended energy range by using the non-perturbative model for the free-electron-gas and the SLPA for the inner-shells.AcknowledgementThis work is supported by the University of Buenos Aires, CONICET and ANPCyT(Argentina), and the IAEA.References[1] https://www-nds.iaea.org/stopping/.[2] Montanari and Dimitriou, Nucl.Instr.Meth.B 408, 50 (2017)[3] Figueroa et al, Phys.Rev.A 75, 010901 (2007).[4] Roth et al, Phys.Rev.Lett 118, 103401 (2017); 119, 163401 (2017)[5] Montanari and Miraglia, Phys.Rev.A 96, 012707 (2017)