A study of the $$^{11}$$ B( $$^{3}$$ He,d) $$^{12}$$ C reaction at incident $$^{3}$$ He energy $$\hbox {E}_{{lab}}$$ = 25 MeV has been performed at the K-130 cyclotron at the University of Jyväskylä, Finland. Differential cross sections have been measured for the 13.35 MeV state and for the states with excitation energy around 20 MeV in $$^{12}$$ C. The data were analyzed with the DWBA method. A tentative assignment, 4 $$^{-}$$ , is given for the state at 13.35 MeV in a joint study of the reaction and inelastic scattering of $$\alpha $$ -particles with the energy of 110 MeV. For the state at 20.98 MeV, the possible spin-parity 3 $$^{-}$$ and the isospin T = 0 are assigned for the first time. Our model description of the broad state at 21.6 MeV is consistent with the previous assignments of isospin T = 0 and spin-parity of 2 $$^{+}$$ or 3 $$^{-}$$ . The excited state at 22.4 MeV may have possible spin-parities of either 6 $$^{+}$$ or 5 $$^{-}$$ . The collected statistics was insufficient to solve this question. Rotational bands which can exist in $$^{12}$$ C were presented.

We demonstrate that the radii of excited nuclear states can be estimated using the (3He, t) charge-exchange reaction and relying on the modified diffraction model.The radius of the 13 N excited state with an excitation energy of E*=2.37 MeV,which lies in a continuous spectrum, is determined. The radius of this state proves to be close to that of the mirror 3.09-MeV state of the 13 C nucleus, which possesses a neutron halo but lies in a discrete spectrum. Thereby, we demon- strate that the 2.37-MeV state of the 13 N nucleus has a proton halo. The analysis is based on published measurements of differential cross sections for relevant reactions.

New experimental data on the inelastic scattering of α-particles on 13C at $$E(\alpha ) = 65$$ and 90 MeV with the excitation of the $$1{\text{/}}2_{3}^{ - }$$ state are reported. Data are analyzed using the modified diffraction model. The determined rms radius of this state coincides within errors with the radius of the $$1{\text{/}}2_{2}^{ - }$$ 8.86 MeV state in 13C and the Hoyle state in 12C. This result is an argument for a similar structure of these states. The unusual result for the compact 3/2– 9.90 MeV state in 13C has been tested by considering its isobar-analog 3/2– 9.48 MeV state in 13N. It has been found that these states have a normal non-increased radius.

C-13 is a good example of a "normal" nucleus that is well described within the shell model. Its level scheme is reliably determined up to excitation energies similar to 10 MeV. However, some questions remain open regarding the structure of low-lying C-13 states. This leads to the increased attention to C-13. In 2014, our group announced the discovery of a state of C-13 with an abnormally small radius. In the framework of the modified diffraction model (MDM) method, analyzing data on alpha-scattering on C-13 at 65 and 90 MeV, it was shown that this state has a radius reduced by 10%. At the same time, theoretical works predict dilute structure and increased radius for this state, and assumptions were made about its rotational structure. Another important question is the search for possible analogues of the Hoyle state in C-13. Confirmed analog of the Hoyle state is the 1/2(-)(8.86 MeV) state in C-13. Another possible candidate is the next 1/2(-) state - 11.08 MeV. Moreover, a hypothesis was put forward about a new type of symmetry in the C-13 structure - D-3h' symmetry. On the basis of D-3h' symmetry, the rotational nature of a whole group of low-lying C-13 states was predicted. In the work, 6 rotational bands were proposed, that is, almost all low-lying C-13 states were distributed among the rotational bands. Thus, a critical analysis of the available data is required to answer the question about the nature of low-lying excited states in C-13.

An experiment on the scattering of 23 MeV deuterons by $$^{9}$$ Be nucleus was carried out. Differential scattering cross sections are obtained for the following states: g.s., 1.68 MeV, 2.43 MeV, 2.78 MeV, 3.05 MeV, 3.82 MeV, 4.70 MeV, 5.59 MeV, 6.38 MeV, 6.76 MeV and 7.94 MeV. The obtained data were analyzed using the distorted wave Born approximation (DWBA) and modified diffraction model (MDM). It was confirmed that the positive parity band $$K^{\pi }$$ = $${\frac{1}{2}}^{+}$$ based on the 1.68 MeV, $${\frac{1}{2}}^{+}$$ state is formed by the 3.05 MeV, $${\frac{5}{2}}^{+}$$ ; 4.70 MeV, $${\frac{3}{2}}^{+}$$ and 6.76 MeV, $${\frac{9}{2}}^{+}$$ states. It was proposed that the 3rd band ( $$K^{\pi }$$ = $${\frac{1}{2}}^{-}$$ ) based on the 2.78 MeV, $${\frac{1}{2}}^{-}$$ state may be formed by the 5.59 MeV, $${\frac{3}{2}}^{-}$$ and 7.94 MeV, $${\frac{5}{2}}^{-}$$ states. The radii of these band states ( $$K^{\pi }$$ = $${\frac{1}{2}}^{+}$$ and $$K^{\pi }$$ = $${\frac{1}{2}}^{-}$$ ) are increased compared to the ground state. Besides, it is found that the 3.82 MeV state has $$J^{\pi }$$ = $${\frac{3}{2}}^{-}$$ and does not belong to any of the rotational bands considered above. Possibly, it is formed as a one-particle state near the excited $$^{8}$$ Be core with the spin $$J_{c}$$ = 2.

The saturation yield of the rhenium radioisotopes 186Re, 188Re, and 189Re on irradiation of a 186W target by the nuclei 4He, 3He, 1H, and 2H with energy 47, 25, 15.3, and 19 MeV, respectively, was measured by the activation method. The chosen energy of the accelerated particles made it possible to minimize the contribution of the activity of long-lived rhenium radioisotopes in the desired radionuclides. The highest yield 3240 ± 330 MBq/μA was obtained for the radioisotope 186Re in the reaction 186W(2H, 2n)186Re. The obtained yield makes it possible to plan on using in radioimmunotherapy the radionuclide 186Re produced by means of this reaction.

The differential cross sections of the B-11(He-3, d)C-12 reaction leading to formation of the 0(+) ground state and the 15.11-MeV 1(+), 16.57-MeV 2(-), and 17.23-MeV 1(-) excited states of C-12 are measured at E-lab = 25 MeV. The analysis of the data is carried out within the coupled-reaction-channels method for the direct proton transfer to the bound and unbound states. The rms radii of the last proton in all states studied are determined. A comparison of the rms radii of the B-12, C-12, and N-12 nuclei in the isobaric analog states (IASs) with isospin T = 1 determined by different methods allows us to arrive at a conclusion that these nuclei in the 1(-) excited states at E-x = 2.62, 17.23, and 1.80 MeV, respectively, possess one-nucleon (neutron or proton) halo structure. The enlarged radii and a large probability of the last neutron to be outside of the range of the interaction potential are also found for the 2(-) states of B-12, C-12, and N-12 at E-x = 1.67, 16.57, and 1.19 MeV, respectively. These IASs also can be regarded as candidates for states with one-nucleon (neutron or proton) halo.

Previously in [1] neutron halo was confirmed for the 2¯, 1.67 MeV and 1¯, 2.62 MeV states in 12 B on base of Asymptotic Normalization Coefficients (ANC) method analysis of the obtained experimental data.An unexpected result was received for the unbound 3¯, 3.39 MeV state.Its halo radius was found to be increased and equal to ~ 5.9 fm.This result can be considered as an evidence of the halo-like structure in this 12 B state.It should be noted that last neutron in this state has a non-zero orbital momentum (l=2).So question arises about possible existence of states with halo in other members of the isobaric triplet 12 B -12 C -12 N. We can expect the formation of a proton halo in the 2¯, 1.19 MeV and 1¯, 1.80 MeV states of 12 N and 2¯, 16.62 MeV and 1¯, 17.23 MeV states of 12 C.To check this prediction preliminary Modified Diffraction Model (MDM) analysis of existing ( 3 He,t) and ( 3 He, 3 He') experimental data was done.

The saturation yield of the rhenium radioisotopes 186 Re, 188 Re, and 189 Re on irradiation of a 186 W target by the nuclei 4 He, 3 He, 1 H, and 2 H with energy 47, 25, 15.3, and 19 MeV, respectively, was measured by the activation method. The chosen energy of the accelerated particles made it possible to minimize the contribution of the activity of long-lived rhenium radioisotopes in the desired radionuclides. The highest yield 3240 ± 330 MBq/μA was obtained for the radioisotope 186 Re in the reaction 186 W( 2 H, 2n) 186 Re. The obtained yield makes it possible to plan on using in radioimmunotherapy the radionuclide 186 Re produced by means of this reaction.

Formation of the 7He heavy isotope was studied in the reactions of stopped pion absorption by light nuclei 9Be, 10,11B and 12,14C. Measurements were performed using the two-arm multilayer semiconductor spectrometer. Contrary to the results of other studies, we observed several narrow highly excited states (Ex > 16 MeV) of 7He. From the analysis of the continuous excitation spectrum in reactions 9Be(π−, d)X and 11B(π−, dd)X it was obtained first indication that the 4He+3n structure is not present in the ground state of 7He.

A study of the neutron structure of the ground state of 7 He has been performed by means of registration and analysis of the decay channels of the residual nuclei following absorption of stopped pions. In particular, the reaction 9 Be ( π − , d )X have been investigated where X denotes any system with five neutrons and two protons – the constituencies of a 7 He nucleus. It was shown that the structure of 7 He is determined by correlations of two neutrons in the states 6 He (0 + ), 6 He (2 + ) and one neutron in the shell p 3/2 . The 4 He+3n structure is not manifested in the ground state of 7 He. The obtained results are consistent with the known data on considerable mixture of configurations “ 6 He in its ground and first excited states plus a neutron” in the ground state of 7 He. Comparison of the diffraction components of the differential cross-sections of the charge-exchange reactions ( t , 3 He) measured on 6 Li and 7 Li allowed extracting the radius of particle-unstable nucleus 7 He. The latter occurred to be approximately equal to those of 6 He and 8 He. The obtained result indicates to existence of the halo-like structure in 7 He.

Two independent methods: Asymptotic Normalization Coefficients (ANC) and Modified Diffraction Model (MDM) were applied to new and existing experimental data to search for states with enhanced radii in isobaric analogue states (IAS) of 12 B and 12 N. The ANC analysis of the 11 B(d,p) 12 B reaction at E d = 21.5 MeV has confirmed neutron halo existence for two states of 12 B: 2 − , 1.67 MeV and 1 − , 2.62 MeV [1]. Some new results were obtained for higher excited states: halo-like states were observed for 0 + , 2.72 MeV and 3 − , 3.39 MeV states. It should be mentioned that the last one is unbound state, which is 19 keV above the neutron emission threshold and in both states last neutron has a non-zero orbital momentum (l n =1 and l n =2 correspondingly). We propose to use MDM to study isobaric analogue states of 12 B in the mirror 12 N nucleus and apply it to analyze the ( 3 He,t) reaction data. The existing in the literature data are not completed enough to make definite conclusion about halo in the 2 − and 1 − states of 12 N. This fact simulated us to carry out a new experiment on the 12 C( 3 He,t) 12 N reaction at the end of 2018. The measurements were conducted at the University of Jyväskylä (Finland) using the K130 cyclotron to produce a 3 He beam at E( 3 He)=40 MeV. The differential cross sections of the 12 C( 3 He,t) 12 N reaction were measured in the c.m. angular range 8°–70°. Preliminary results for angular distributions are obtained. MDM analysis of preliminary ( 3 He,t) experimental data is done.

The isobaric analog states with isospin T = 1 in triplet of the A = 14 nuclei: 14C, 14N, and 14O, are studied. The signs of a neutron halo in the 1− (6.09 MeV) state of 14C have been revealed earlier by two groups. We confirm this result and study isobaric analog 1− states of neighboring 14N and 14O nuclei. The differential cross sections for the 14C(α, α)14C* (6.09 MeV, 1−) inelastic scattering, the 13C(3He, d)14N* (8.06 MeV, 1−), and the 14N(3He, t)14O* (5.17 MeV, 1−) reactions are analyzed by two methods: the modified diffraction method and the method of asymptotic normalization coefficients. The rms radii for all three mirror nuclei in the studied 1− states are found almost the same: (2.7 ± 0.1) fm for 14C, (2.67 ± 0.07) fm for 14N, and (2.6 ± 0.2) fm for 14O. The signs of the proton halo in the 1− state of 14N are identified for the first time.

The differential cross sections for the 12C(3He, t)12N reaction leading to formation of the 1+ (ground state), 2+ (0.96 MeV), 2− (1.19 MeV), and 1− (1.80 MeV) states of 12N are measured at E(3He) = 40 MeV. The analysis of the data is carried out within the modified diffraction model and distorted wave Born approximation. Increased rms radii have been obtained for the ground, 2− (1.19 MeV), and 1− (1.80 MeV) states. We revealed that 12B, 12N, and 12C in the isobaric analogue states with T = 1, and spin-parities 2− and 1− have increased radii and exhibit properties of neutron and proton halo states.

Method for production of alpha emitter 149 Tb by irradiation of 151 Eu with 70 MeV 3 He nuclei is proposed. For the first time, the cross sections for the formation of isotopes 149,150,151,152 Tb were measured experimentally using a stack foil technique in the 3 He particles energy range 70 → 12 MeV. The thick target yield of 149 Tb is 39 MBq/μAh, or 230 MBq/μA 149 Tb at saturation. The optimal energy range from the point of view of radioisotopic purity is 70 → 40 MeV. At these conditions about 150 MBq/μA 149 Tb can be produced in 8 hours irradiation, which is sufficient for therapeutic applications. The main impurities are 150 Tb (~100% in activity) and 151 Tb (~30% in activity). The proposed method surpasses its counterparts by the high content of the target isotope in the natural mixture and the simplicity of the radiochemical separation of 149 Tb from the bulk target material.

The experiment was done to study B-11(He-3, d)C-12 reaction with energy E(He-3)=25 MeV. The aim of the experiment is to determine the properties of C-12 states at high excitation energies and in particular to verify which of the conflicting spin-parity assignments of the 13.35 MeV state (2(-) or 4(-)) should be assigned. Behavior of the experimental angular distribution and also the DWBA calculation correspond to spin parity 4(-) for 13.35 MeV state.

The activation method was used to determine the cross sections of the nuclear reactions 82Kr(3He, 3n)82Sr, 83Kr(3He, 4n)82Sr, and 84Kr(3He, 5n)82Sr in the 3He energy range 20–75 MeV on targets with highly enriched krypton isotopes. The results were used to calculate the 82Sr yield in a yield-optimized cascade target with 82,83,84Kr and initial 3He energy 75 MeV. The computed 82Sr yield was equal to 2.9 MBq/(μA·h), which makes it possible to count on the practical application of the method of 82Sr production based on the reactions 82,83,84Kr(3He, xn)82Sr in a cascade target.

The analysis of the available data on the α + 9Be elastic scattering in the energy range from 28 to 104 MeV, including recent measurements at energies of 30, 40, and 90 MeV is carried out. The parameters of the semi-microscopic potential are obtained in the framework of the dispersion optical model, in which the exchange components of the average field potential were calculated using the previously proposed pseudo-oscillator approximation for the single-particle density matrix. The found potential is tested using the distorted wave method on the analysis of inelastic scattering in the considered energy region with excitation of the 5/2− (2.43 MeV) and 7/2− (6.38 MeV) levels of the ground-state rotational band. The potential parameters used for the output channel were estimated on the basis of the energy dependence. A satisfactory description of the angular distributions and the values of the deformation length is obtained.