1–5 Jul 2024
Dubna, Russia
Europe/Moscow timezone

THE ALIGNMENT OF THE 20Ne(2+; 1.63 MeV) NUCLEUS FORMED IN 19F(α,t)20Ne REACTIONS AT Eα=30.3 MeV

Not scheduled
20m

Speaker

Prof. Natal'ya Zelenskaya (SINP MSU)

Description

Experimental and calculated the F2(θt) and F4(θt) alignment angular dependences of the 20Ne nucleus in the excited state 2+ (1.63 MeV), formed in the reactions 19F(α,t)20Ne at energies Eα=30.3 MeV are presented. The orientation parametersFk (k=1,,2J) are polynomials in the mean values of the powers Jz and are included in the expression for the interaction energy of nuclei with an electromagnetic field [1]. Since the method of angular correlations used in this work makes it possible to experimentally determine only even components, we consider the parameters of the quadrupole F2 and hexadecapole F4 orientations. In the case of an isotropic spin distribution, the alignment is zero. The maximum value of the parameters is achieved at the maximum value of the spin projection M=J onto the quantization axis:

F2=2J+15(J+1)(2J+3)J(2J1)T20,
F4=2J+16(2J+3)(2J+2)(2J+4)(2J+5)J(J1)(2J1)(2J3)T40,
where
TK0=12J+1ρK0ρ00=12J+1(1)JMJMJM|K0,
and ρk0(θt) is the spin tensor component of the density matrix of the nucleus.
Experimental information was obtained on the basis of previously retrieved [2] spin-tensors ρkκ(θt) density matrices of the 20Ne nucleus (2+ 1.63 MeV) by measuring of the angular particle-gamma correlations. The experimental orientation parameters are compared with the calculated ones under the assumption of CCBA taking into account the mechanisms of nucleon stripping and the coupled channel method (FRESCO code [3]). The calculated alignments are in satisfactory agreement with the experimental ones.

  1. G.R. Khutsishvili. Uspekhi Fizicheskikh Nauk. V.53, P. 381 (1954).
  2. A.V. Ignatenko et al. Yadernaya Fizika. V. 58, P. 208 (1995).
  3. I. J. Thompson. Comp. Phys. Rep. 7, 167 (1988); http://www. fresko. org.uk/.
Section Experimental and theoretical studies of nuclear reactions

Primary authors

Prof. Natal'ya Zelenskaya (SINP MSU) Dr Lidiya Galanina (SINP MSU) Dr Victor Lebedev (SINP MSU) Dr Andrey Spassky (SINP MSU) Dr Nina Orlova (SINP MSU)

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