The NA61/SHINE experiment at the CERN Super Proton Synchrotron studies the onset of deconfinement in strongly interacting matter through a beam energy scan of particle production in collisions of nuclei of varied sizes. This paper presents results on inclusive double-differential spectra, transverse momentum and rapidity distributions and mean multiplicities of $$\pi ^\pm $$π ± , $$K^\pm $$K ± , p and $$\bar{p}$$p ¯ produced in $$^{40}\hbox {Ar+}^{45}\hbox {Sc}$$40 Ar+ 45 Sc collisions at beam momenta of 13A, 19A, 30A, 40A, 75A and 150A $$\text{ Ge }\hspace{-1.00006pt}\text{ V }\!/\!c$$Ge V / c . The analysis uses the 10% most central collisions, where the observed forward energy defines centrality. The energy dependence of the $$K^\pm $$K ± / $$\pi ^\pm $$π ± ratios as well as of inverse slope parameters of the $$K^\pm $$K ± transverse mass distributions are placed in between those found in inelastic $$p+p$$p + p and central Pb + Pb collisions. The results obtained here establish a system-size dependence of hadron production properties that so far cannot be explained either within statistical or dynamical models.

The critical point of dense, strongly interacting matter is searched for at the CERN SPS in ⁴⁰Ar + ⁴⁵Sc collisions at 150A Ge V /c. The dependence of second-order scaled factorial moments of proton multiplicity distribution on the number of subdivisions of transverse momentum space is measured. The intermittency analysis is performed using both transverse momentum and cumulative transverse momentum. For the first time, statistically independent data sets are used for each subdivision number. The obtained results do not indicate any statistically significant intermittency pattern. An upper limit on the fraction of correlated proton pairs and the power of the correlation function is obtained based on a comparison with the Power-law Model developed for this purpose.

The critical point of strongly interacting matter is searched for at the CERN SPS by the NA61/SHINE experiment in central $$^{40}$$40 Ar + $$^{45}$$45 Sc collisions at 13 A, 19 A, 30 A, 40 A, and 75 A GeV/c. The dependence of the second-order scaled factorial moments of proton multiplicity distributions on the number of subdivisions in transverse momentum space is measured. The intermittency analysis uses statistically independent data sets for every subdivision in transverse and cumulative-transverse momentum variables. The results obtained do not indicate the searched intermittent pattern. An upper limit on the fraction of correlated protons and the intermittency index is obtained based on a comparison with the Power-law Model.

Neutron activation and gamma spectrometry are usable also for the determination of cross-sections of different neutron reactions. We have studied the cross-section of yttrium (n,xn) threshold reactions using quasi mono-energetic neutron source based on the reaction on 7Li target at Nuclear Physics Institute of ASCR in Rez. Yttrium (n,xn) threshold reactions are suitable candidates for fast neutron field measurement by activation detectors. Fast neutron field monitoring is necessary already today at a wide range of accelerator facilities and will gain on importance in future fast reactors of generation IV, accelerator transmutation systems or fusion reactors. The knowledge of the cross-sections is crucial for such purpose. Unfortunately, the cross-section is sufficiently known only for 89Y(n,2n)88Y reaction. For higher orders of reactions there are almost no experimental data. Special attention was paid to the 89Y(n,3n)87Y reaction. The nuclei are produced, both in the ground state with half-life 79.8hours and in the isomeric state with half-life 13.38hours. The isomer decays mainly through the gamma transition to the ground state, the beta decay of the excited state is negligible within our accuracy. The cross-sections of both 87Y productions were analyzed