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

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6-4: a) Inner fusion barriers B Figure λ (t) in λ as a function <strong>of</strong> time for the systems fus Pd + 110 Pd (solid curve) and 56 Cr + 164 Er (dashed curve) which produce the same com- 110 nucleus pound 220 The nuclei are considered spherical with ε = 0.74. The parameter U. Γ −1 0 = 0.030MeV−1 used in the calculation <strong>of</strong> single-particle widths. For times smaller is 6 × 10 than −21 and 8 × 10 s −21 for η =0and0.5, respectively, the potential V (λ, t) is only re- s and has no barrier (see Fig. 6-2). b) Calculated adiabatic potential energy <strong>of</strong> the DNS pulsive the touching configuration <strong>of</strong> the nuclei as a function <strong>of</strong> mass asymmetry η for reactions in to the same compound nucleus leading 220 The potential is calculated within the adiabatic U. TCSM with (solid curve) and without (dashed curve) shell corrections. The fusion barrier B η in η for the system 110 Pd+ 110 Pd is shown. 93 fus
Chapter 7 In the quasi-fission process, the large mass rearrangements between the interacting heavy ions occur at a short time scale [11, 112]. One <strong>of</strong> the experimental signatures [113] <strong>of</strong> this process is the large width <strong>of</strong> mass distributions, incompatible with compound nucleus fission. Con- ceptually, the quasi-fission bridges the gap [106] between the deep-inelastic collisions, where the reaction partners get into sufficiently close contact to exchange many particles practically without altering their average mass and charge [33], and the complete fusion process, where the reaction partners completely lose their identity by transformation into a compound nucleus [113]. All these types <strong>of</strong> reaction are organically connected and are derived from the evolution <strong>of</strong> a dinuclear system (DNS) [18, 34] which is formed in the entrance channel during the capture stage <strong>of</strong> reaction, after the dissipation <strong>of</strong> the collision kinetic energy. The decay <strong>of</strong> the DNS when it evolves in the mass asymmetry coordinate predestines the charge and mass distributions <strong>of</strong> the reaction products. The competition between the complete fusion and the quasi-fission process occurs in reactions with massive nuclei at low bombarding energies (< 15 MeV/u) [34]. In this chapter, the quasi-fission process is described as the evolution <strong>of</strong> the DNS in the Z (A) coordinate by nucleons transfer between nuclei taking into account the DNS decay in the internuclear distance R (or elongation λ). Here, Z (A) denotes the charge (mass) number <strong>of</strong> the light fragment <strong>of</strong> the DNS. For the sake <strong>of</strong> simplicity, we will use the variables Z(A) instead <strong>of</strong> the charge (mass) asymmetry η (ηZ). Since the isotopic composition <strong>of</strong> the nuclei forming the DNS 94
Page 1 and 2:
Effects of
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1 Introduction 6 1.1 The DNS-concep
Page 5 and 6:
Chapter 1 The elements existing in
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observed the rapid fall-of<
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Figure 1-1 illustrates the compound
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smaller than the extra-extra push e
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fusion and quasi-fission processes
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In the present chapter we have pres
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higher collective velocities to rep
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2.1 General considerations We want
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couplings. Diabatic basis states ψ
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Chapter 3 The synthesis of<
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is calculated within the TCSM using
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E adiab (MeV) n E diab (MeV) n 30 2
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E diab (MeV) n 60 55 50 45 40 100Mo
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3-5: Diabatic potentials for the sy
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3-7: The same as in Fig. 3-6 for th
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The estimated collective velocities
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3-10: Diabatic contributions as a f
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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 and 52: 4-1: Fusion barriers B Table TCSM
Page 53 and 54: U (MeV) 40 30 20 10 20 10 0 a) b) 9
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: 6-3: Time-dependent average width <
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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