March, 2006SERC Course1  Z>92 (Heaviest Element in Nature) and upto Z= achieved by n irradiation or p,  and d bombardment in Cyclotron ( ) (LBL)  Z= by Light or Heavy-ion induced Fusion -evaporation using heavy element targets ( ) Z= Heavy ion inuced fusion 208 Pb, 209 Bi targets (GSI) Identified by recoil separation technique and connecting to known daughter decay after implanting into Si strip detectors.  Z= Ca+Pu,Am,Cm,Cf (JINR, Dubna) Identified by gas filled separators and Si strip setectors Search for Superheavy element and Role of Fission Dynamics

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March, 2006SERC Course6 Cross-section data and extrapolated values for cold-fusion Reactions (1n -evaporation channel) Cross-section increases with increasing isospin

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March, 2006SERC Course8 48 Ca+ 242 Pu-> n 48 Ca+ 244 Pu-> n 48 Ca+ 244 Pu-> n E * ~33 MeV E * ~34-38 MeV

March, 2006SERC Course9 Yury Ts. OganessianPure Appl. Chem., Vol. 76, No. 9, pp. 1715–1734, 2004.

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March, 2006SERC Course11 48 Ca+ 244 Pu

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March, 2006SERC Course13 The flight time of the reaction products through SHIP is 2 ms.

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March, 2006SERC Course16 ∙ Cold Fusion 208 Pb and 209 Bi targets bombarded by the following projectiles: 48 Ca, 50 Ti, 54 Cr, 58 Fe, 62 Ni, 64 Ni, 70 Zn, 76 Ge, 82 Se, and 86 Kr. ∎ Hot Fusion 48 Ca projectiles bombarded targets of 238 U, 244 Pu, 243 Am, 245 Cm, 248 Cm, and 249 Cf,

March, 2006SERC Course17 B LD f gradually disappears Spherical Deformed

March, 2006SERC Course18 Fission barrier calculations of Smolanzuk et al. 106 Sg has highest barrier with half life of 3 hrs

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March, 2006SERC Course20 Extra push energies Swiateck i For Z1Z2>1000 to 1650 depending on the value of the charge asymmetry, Zp/ZT.

March, 2006SERC Course21 Onset of fusion limitation Due to Extra push energies No hindrance Effective fissility : weighted mean of mono-nuclear and binary With weight for binary taken as 1/3

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March, 2006SERC Course23 Injection direction Fusion area inside Saddle point Difference in energy Between touching Point and saddle point Small due to shell structure Of Ca and Pb All trajectories reaches fusion

March, 2006SERC Course24 Quasi-fission is dominant Extra pocket in mass Symmetric region Deep Quasi- fission

March, 2006SERC Course25 The curve V (Z,L = 0) (for the value of R corresponding to the pocket) has a few local minima, which reflect the shell structure in the interacting nuclei. Evgeni A. Cherepanov Brazilian Journal of Physics, vol. 34, no. 3A, September, 2004

March, 2006SERC Course26 48 Ca+ 208 Pb EX=50 MeV Aritomo and Ohta Pre-print Nuclear Physics A 744 (2004) 3–14 Mass asymm fluctuates around 0.5 and then relaxes quickly and Trajectory move to main pocket

March, 2006SERC Course27 48 Ca+ 244 Pu Ex=50 MeV Critical stage Turning stage For FF mass Asymmetries large For QF neck develops and speeds up fission keeping mass asymm. For deep QF mass asymm Relaxed in sub-pocket At TS

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March, 2006SERC Course29 The smaller formation probability due to inhibition of fusion by competing mechanism:DIC,QF,FF,PEF Asymmetric channels: higher E* and unfavourable for survival

March, 2006SERC Course30 Transition from FF to QF QF Mass distribution for FF is asymmetric in shape With peak around 132

March, 2006SERC Course31 Measurements at LNL,Legnaro (Italy) MeV 80 Se Pb 372 MeV 56 Fe+ 232 Th Measurement of fragment mass and kinetic energy and neutron correlations 80 Se Th MeV

March, 2006SERC Course32 Schematics of the setup for Se+Pb,Th experiment

March, 2006SERC Course33 80 Se+ 232 Th470 MeV 80 Se+ 208 Pb470 MeV DIC dominates but significant events around symmetry

March, 2006SERC Course34 80 Se+ 232 Th470 MeV 80 Se+ 208 Pb470 MeV Se+Pb more asymmetric compared to Se+Th QF is expected to be more for Se+Th

March, 2006SERC Course35 higher extra-push energy in the case of 80 Se+ 232 Th

March, 2006SERC Course36 80 Se+ 208 Pb Se+ 232 Th ν sf tot =10±2 for Se+Pb 12±1 for Fe+Th =17±2 for Se+Th

March, 2006SERC Course37 on average of about 0.6 neutron per unit Z

March, 2006SERC Course38 an increase of about 0.54 neutron per unit Z excitation energy gained by the system in its transition from the saddle to the scission point (the term ΔEx by Hilscher) that is known to show a strong mass and Z dependence.

March, 2006SERC Course39 JINR,Dubna

March, 2006SERC Course40 41 detectors of DEMON at Dubna T. Materna et al. Nuclear Physics A734 (2004) 184-l 87 The pre-scission neutron multiplicity distribution simulated using backtracing procedure show two components for Ca+Pu Whereas for Ca+Pb only one component is seen FF QF A/2±30 208±20

March, 2006SERC Course41 ?? Connectecd with known species Self-consistent

March, 2006SERC Course42 Change from Hot fusion to Cold fusion For higher N-Z

March, 2006SERC Course43 Survival probability fissiondelay Depends on fission delay And speed of cooling neutron Mainly by neutronevaporation

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March, 2006SERC Course46 Expected intensities s -1 for neutron-rich radioactive beams SPIRAL 24 Ne 7 x 10 7 HI based 44 Ar 5 x 10 7 PIAFE 78 Zn Ge 2 x Kr 2 x 10 9 Region beyond Z= 114 needs beam intensities in excess of s -1. Reactor based With MAFF and spallation facility with 100μA proton of 1GeV Intensities may go up by 3 to 4 orders of magnitude

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