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D. O. Krivenkov

Publications and source records attributed to D. O. Krivenkov.

13 recordsLinked to original sources

Nuclotron internal target polarimeter for the measurements of the deuteron and proton beam polarization

Studies of spin-dependent effects at the Nuclotron/NICA accelerator complex at JINR require precise measurements of the deuteron and proton beam polarization. The vector polarization of the deuteron beam was measured at the energies of 200, 500, 550, and 650 MeV/nucleon by a detection system of scintillation counters placed at the Nuclotron internal target. Considering the deuteron beam as a beam of weakly bound protons and neutrons, the asymmetries of scattering of protons from deuterons on polyethylene and carbon targets were determined. The polarization of the polarized proton beam accelerated for the first time at the Nuclotron up to 500 MeV was also measured.

physics.ins-det

Deuteron analyzing powers $A_y$, $A_{yy}$ and $A_{xx}$ in dp-elastic scattering at large transverse momenta

The results on the the vector $A_y$, $A_{yy}$ and $A_{xx}$ analyzing powers in deuteron-proton elastic scattering at large scattering angles are presented. These data were obtained at internal target at JINR Nuclotron in the energy range 400-1800 MeV using polarized deuteron beam from new polarized ion source. New data on the deuteron analyzing powers in the wide energy range demonstrate the sensitivity to the short-range spin structure of the isoscalar nucleon-nucleon correlations.

nucl-ex

Measurement of the deuteron beam polarization at internal target at Nuclotron for DSS experiment

The current deuteron beam polarimetry at Nuclotron is provided by the Internal Target polarimeter based on the use of the asymmetry in dp- elastic scattering at large angles in the cms at 270 MeV. The upgraded deuteron beam polarimeter has been used obtain the vector and tensor polarization during 2016/2017 runs for the DSS experimental program. The polarimeter has been used also for tuning of the polarized ion source parameters for 6 different spin modes.

physics.ins-det

First results on the measurements of the proton beam polarization at internal target at Nuclotron

The spin program at NICA using SPD and MPD requires high intensity polarized proton beam with high value of the beam polarization. First results on the measurements of the proton beam polarization performed at internal target at Nuclotron are reported. The polarization of the proton beam provided by new source of polarized ions has been measured at 500 MeV using quasielastic proton-proton scattering and DSS setup at internal target. The obtained value of the vertical polarization of ~35 % is consistent with the calculations taking into account the current magnetic optics of the Nuclotron injection line.

physics.ins-det

Coherent Dissociation of Relativistic N-12 Nuclei

The dissociation of relativistic $^{12}$N nuclei having a momentum of 2 GeV/c per nucleon and undergoing the most peripheral interactions in a track emulsion is studied. The picture of charged topology of product ensembles of relativistic fragments and special features of their angular distributions are presented.

nucl-ex

Dissociation of C-10 Nuclei in a Track Nuclear Emulsion at an Energy of 1.2 GeV per Nucleon

The charge topology in the fragmentation of $^{10}$C nuclei in a track nuclear emulsion at an energy of 1.2 GeV per nucleon is studied. In the coherent dissociation of $^{10}$C nuclei, about 82% of events are associated with the channel $^{10}$C $\rightarrow$ 2$α+$ 2\emph{p}. The angular distributions and correlations of product fragments are presented for this channel. It is found that among $^{10}$C $\rightarrow$ 2$α+$ 2\emph{p} events, about 30% are associated with the process in which dissociation through the ground state of the unstable $^9$Be$_{g.s.}$ nucleus is followed by $^8$Be$_{g.s.} +$ \emph{p} decays.

nucl-ex

Clustering in relativistic dissociation of $^9$be, $^9$c, $^{10}$c and $^{12}$n nuclei

The dissociation features in nuclear track emulsion of $^9$Be, $^{9,10}$C, and $^{12}$N nuclei of 1.2 A GeV energy are presented. The data presented for the nucleus $^9$Be can be considered as evidence that there is a core in its structure in the form of 0$^+$ and 2$^+$ states of the $^8$Be nucleus having roughly equal weights. Events of coherent dissociation $^9$C$\rightarrow 3^3$He associated with the rearrangement of the nucleons outside the $α$-clustering are identified. A pattern of the charge fragment topology in the dissociation of $^{10}$C and $^{12}$N nuclei is obtained for the first time. Contribution of the unbound nucleus decays to the cascade process $^{10}$C$\rightarrow ^9$B$\rightarrow ^8$Be is identified.

nucl-ex

Dissociation of relativistic $^{10}$C nuclei in nuclear track emulsion

Dissociation of 1.2 A GeV $^{10}$C nuclei in nuclear track emulsionis is studied. It is shown that most precise angular measurements provided by this technique play a crucial role in the restoration of the excitation spectrum of the 2$α$+2p system. Strong contribution of the cascade process $^{10}$C$\rightarrow ^9$B$\rightarrow ^8$Be identified.

nucl-ex

Exposure of Nuclear Track Emulsion to a Mixed Beam of Relativistic $^{12}$N, $^{10}$C, and $^7$Be Nuclei

A nuclear track emulsion was exposed to a mixed beam of relativistic $^{12}$N, $^{10}$C, and $^7$Be nuclei having a momentum of 2 GeV/$c$ per nucleon. The beam was formed upon charge exchange processes involving $^{12}$C primary nuclei and their fragmentation. An analysis indicates that $^{10}$C nuclei are dominant in the beam and that $^{12}$N nuclei are present in it. The charge topology of relativistic fragments in the coherent dissociation of these nuclei is presented.

nucl-ex

Coherent Dissociation of Relativistic C-9 Nuclei

Results on the coherent dissociation of relativistic $^9$C nuclei in a nuclear track emulsion are described. These results include the charge topology and kinematical features of final states. Events of C-9 to 3He-3 coherent dissociation are identified.

nucl-ex

Electromagnetic dissociation of relativistic $^8$B nuclei in nuclear track emulsion

Experimental data on fragmentation channels in peripheral interactions of $^8$B nuclei in nuclear track emulsions are presented. A detailed analysis made it possible to justify selections of events of the electromagnetic-dissociation process $^8$B $\to^7$Be + \emph{p} and to estimate its cross section. Events of $^{10}$C peripheral dissociation that were observed in the same exposure are described.

nucl-ex