Effects of diabaticity on fusion of heavy nuclei in the dinuclear model ...

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products. However, in the driving potential calculated with the phenomenological method the peculiarities <strong>of</strong> the single-particle spectra <strong>of</strong> the DNS nuclei are not taken into account explicitly. The shell effects in the driving potentials calculated with the TCSM-method and the alternative microscopical method reflect the influence <strong>of</strong> peculiarities <strong>of</strong> the single-particle spectra near the Fermi surface on the nucleon exchange process. For this reason, these driving potentials can carry more information about the DNS evolution in η than the driving potential calculated with the phenomenological method. It is obvious that the position <strong>of</strong> the initial configuration η i defines the evolution direction <strong>of</strong> the DNS in η. The driving potentials calculated with the TCSM- and with the alternative microscopical methods have few local minima. The absence <strong>of</strong> local minima for some magic nuclei in the dinuclear system can be explained by the shell structure <strong>of</strong> the conjugated nucleus and the influence <strong>of</strong> the neutron subsystem. The effect <strong>of</strong> the deformations <strong>of</strong> the nuclei on the driving potential is presented in Figs. 4-6b) and 4-7b) for the dinuclear systems 180 Hg and 246 Fm, respectively. Here, the driving potential calculated within the TCSM and the phenomenological potential are shown.We assume that the deformations take the effects <strong>of</strong> polarisation <strong>of</strong> the nucleus induced by the mean-field <strong>of</strong> the other nucleus into account. The potential energy <strong>of</strong> the DNS with prolate nuclei is smaller than the potential energy with spherical nuclei (Figs. 4-6a) and 4-7a) ) because the Coulomb energy becomes larger for spherical nuclei. In this case, the fusion barrier in η gets smaller than the one obtained with spherical nuclei. For oblate deformations <strong>of</strong> the nuclei, the potential energy and the fusion barrier in η are larger than for spherical nuclei. In reality, some averaging over the orientations <strong>of</strong> the nuclei has to be carried out in the initial DNS. The deformation effects produce fluctuations <strong>of</strong> the value <strong>of</strong> the fusion barrier in η around the value obtained for spherical nuclei. In the present version <strong>of</strong> the TCSM, the intrinsic symmetry axes <strong>of</strong> the deformed nuclei lie along the internuclear axis. For arbitrary orientations <strong>of</strong> the intrinsic symmetry axes <strong>of</strong> the deformed nuclei, a more general TCSM [81] should be used. Calculations with the method suggested in [65] reveal a weak dependence <strong>of</strong> the potential on the orientations <strong>of</strong> the nuclei. In order to completely take into account the deformation effect in the driving potential calculated with the alternative microscopical method, the single-particle levels should be taken for deformed nuclei. For the sake <strong>of</strong> simplicity, we use the single-particle levels <strong>of</strong> spherical nuclei in the present calculations. However, the fit <strong>of</strong> the Fermi surface by the 53
U (MeV) 40 30 20 10 20 10 0 a) b) 90Zr + 90Zr 10 20 30 40 Z 180Hg TCSM phen. micro. 4-6: a) Driving potentials for the system Figure 180 as a function <strong>of</strong> the charge number Hg <strong>of</strong> the light nucleus <strong>of</strong> the DNS: potential calculated with the TCSM-method (solid line), Z phenomenological potential (dashed line) and the potential calculated with the alternative the method for T =1MeV (dotted line). The nuclei are considered as spherical. The microscopical indicates the reaction arrow 90 + Zr 90 b) The same as in a) but with deformed nuclei in Zr. driving potential calculated with the TCSM- and with the phenomenological methods. The the deformations are taken from Refs. [70, 71] 54
Page 1 and 2: Effects of
Page 3 and 4: 1 Introduction 6 1.1 The DNS-concep
Page 5 and 6: Chapter 1 The elements existing in
Page 7 and 8: observed the rapid fall-of<
Page 9 and 10: Figure 1-1 illustrates the compound
Page 11 and 12: smaller than the extra-extra push e
Page 13 and 14: fusion and quasi-fission processes
Page 15 and 16: In the present chapter we have pres
Page 17 and 18: higher collective velocities to rep
Page 19 and 20: 2.1 General considerations We want
Page 21 and 22: couplings. Diabatic basis states ψ
Page 23 and 24: Chapter 3 The synthesis of<
Page 25 and 26: is calculated within the TCSM using
Page 27 and 28: E adiab (MeV) n E diab (MeV) n 30 2
Page 29 and 30: E diab (MeV) n 60 55 50 45 40 100Mo
Page 31 and 32: 3-5: Diabatic potentials for the sy
Page 33 and 34: 3-7: The same as in Fig. 3-6 for th
Page 35 and 36: The estimated collective velocities
Page 37 and 38: 3-10: Diabatic contributions as a f
Page 39 and 40: effects give a justification for th
Page 41 and 42: The similarity of
Page 43 and 44: 4.1.3 Alternative microscopical met
Page 45 and 46: to the DNS concept [18, 34], cross
Page 47 and 48: U (MeV) 28 27 26 25 24 23 22 21 20
Page 49 and 50: U (MeV) 35 30 25 20 15 10 90Zr + 12
Page 51: 4-1: Fusion barriers B Table TCSM
Page 55 and 56: experimental separation energy allo
Page 57 and 58: means a neglect of
Page 59 and 60: the case of an ind
Page 61 and 62: single particle density matrix exte
Page 63 and 64: following ratio in the limit <stron
Page 65 and 66: 5-1: Dependence of
Page 67 and 68: the microscopical mass parameter <s
Page 69 and 70: 5-3: Mass parameter Mεε as a func
Page 71 and 72: 5-4: Mass parameter Mεε as a func
Page 73 and 74: the approximate expressions (Eqs. (
Page 75 and 76: (10 3 m fm 2) M , M λλ εε 25 20
Page 77 and 78: (10 3 m fm 2) M εε M (10 λλ 4 m
Page 79 and 80: ~ f k (MeV -1) 0,20 0,15 0,10 0,05
Page 81 and 82: V (MeV) 30 25 20 15 10 5 0 -5 -10 1
Page 83 and 84: to the dependence of</stron
Page 85 and 86: where the lifetime t 0 of</
Page 87 and 88: 6-2: a) Time-dependent dynamical po
Page 89 and 90: Table 6-1: Quasi-fission and inner
Page 91 and 92: 6-3: Time-dependent average width <
Page 93 and 94: Chapter 7 In the quasi-fission proc
Page 95 and 96: The value of t0 is
Page 97 and 98: Y Z Y A 0,10 0,08 0,06 0,04 0,02 0,
Page 99 and 100: estimated from the difference betwe
Page 101 and 102: elements from Z=104 to Z=112 in the
Page 103 and 104:
fission process is an important fac
Page 105 and 106:
the neck coordinate ε and
Page 107 and 108:
• The time-dependent transition b
Page 109 and 110:
Appendix A For describing nucleus-n
Page 111 and 112:
where The volume is V0 = 1 2 m0ϖ 2
Page 113 and 114:
ϕ nz(z) = ⎧ ⎪⎨ ⎪⎩ C−1
Page 115 and 116:
Appendix B The collective response
Page 117 and 118:
[1] S.G.Nilsson et al., Phys. Lett.
Page 119 and 120:
[27] N.V.Antonenko et al., in 1 st
Page 121 and 122:
[63] Yu.F.Smirnov and Yu.M.Tchuvil
Page 123 and 124:
[97] H. Hofmann et
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