Quasifission Process Research Articles

Effect of the charge asymmetry and orbital angular momentum in the entrance channel on the hindrance to complete fusion

The hindrance to complete fusion is studied as a function of the charge asymmetry of colliding nuclei and orbital angular momentum of the collision. The formation and evolution of a dinuclear system (DNS) in the heavy-ion collisions at energies near the Coulomb barrier is calculated in the framework of the DNS model. The DNS evolution is considered as nucleon transfer between its fragments. The results prove that a hindrance at formation of a compound nucleus (CN) is related with the quasifission process, which is breakup of the DNS into products instead to reach the equilibrated state of the CN. The role of the angular momentum in the charge (mass) distribution of the reaction products for the given mass asymmetry of the colliding nuclei has been demonstrated. The results of this work have been compared with the measured data for the quasifission yields in the C12+Pb204 and Ca48+Er168 reactions to show the role of the mass asymmetry of the entrance channel. Published by the American Physical Society 2024

Study of Entrance Channel Effects on Fusion–Fission and Quasi-fission Processes

Study of Entrance Channel Effects on Fusion–Fission and Quasi-fission Processes

Analysis of the shell effect of fission fragments in the quasi-fission process

The process in superheavy element synthesis in which two nuclei collide and fission before forming a compound nucleus is called quasi-fission. The dynamical model used in our calculations is highly reproducible in calculating the total kinetic energy (TKE) of actinide fission. However, there is a problem in the reproducibility of TKE of quasi-fission in the current calculations using the dynamical model. Our calculations show that the TKE of mass asymmetry is lower than the experimental data. The reason for this is that the shell effect of fission fragments is not considered. In this study, we attempted to reproduce mass-asymmetric quasi-fission with shell effects by using a dynamical model. The objective is to analyze the calculation results and follow the time evolution of the shape of the nucleus to deepen our understanding of the dynamics of quasi-fission.

Investigation on the Quasifission hindrance to synthesis 298Og

Formation of a compound nucleus and production of its evaporation residue are hindered by quasi-fission process. It reduces the evaporation residue cross section since it takes place before the target and projectile combines to form a composite nucleus. We study the quasifission barriers (Bqf) for 14 fusion reactions in the formation of superheavy element 298Og within the framework of the di-nuclear system model. In particular, the influence of entrance channel parameters on quasifission barriers has been investigated. We notice that the quasifission barriers decreases with an increase in angular momentum and fusion barrier height. We constructed semi-empirical formulae for Bqf as a function of mean fissility. The fusion reaction 48Ca+250Cf poses larger Bqf. The larger evaporation cross section is observed for this fusion reaction for 3n evaporation channel with the cross-section of 0.81pb. Similarly, a smaller evaporation cross-section of about 0.033pb is observed for 51Cr+247Pu fusion reaction for 4n evaporation channel with both projectile and target being deformed, unlike to the previous reaction with spherical projectile and deformed target.

Production cross sections of new neutron-rich isotopes with Z=92–106 in the multinucleon transfer reaction Au197+Th232

The multinucleon transfer reactions $^{197}\mathrm{Au}+^{232}\mathrm{Th}, ^{186}\mathrm{W}+^{232}\mathrm{Th}$, and $^{238}\mathrm{U}+^{232}\mathrm{Th}$ are investigated within the framework of dinuclear system (DNS) model with a decay model gemini$++$. The calculated isotopic production cross sections in the $^{136}\mathrm{Xe}+^{249}\mathrm{Cf}$ reaction at ${E}_{\mathrm{c}.\mathrm{m}.}=567\phantom{\rule{0.28em}{0ex}}\mathrm{MeV}$ can reproduce the experimental data well. Due to the subshell closures, the behavior of ``inverse'' quasifission process is found in the collisions of $^{186}\mathrm{W}+^{232}\mathrm{Th}$ and $^{197}\mathrm{Au}+^{232}\mathrm{Th}$. The reaction $^{197}\mathrm{Au}+^{232}\mathrm{Th}$ is more advantageous to produce neutron-rich isotopes with $Z=92--106$ than $^{186}\mathrm{W}+^{232}\mathrm{Th}$ and $^{238}\mathrm{U}+^{232}\mathrm{Th}$, because it has the lowest value of the potential energy that needed to overcome in the nucleon transfer process. Furthermore, the incident energy dependence of isotopic production cross sections in the reaction $^{197}\mathrm{Au}+^{232}\mathrm{Th}$ is studied. It is found that ${E}_{\mathrm{c}.\mathrm{m}.}=756.47$ MeV is more suitable for producing new isotopes with $Z=92--98$, while ${E}_{\mathrm{c}.\mathrm{m}.}=690.69$ MeV is the optimal incident energy for $Z=99--106$. The effect of incident energy on the interaction time is also investigated. The production cross sections of 88 unknown neutron-rich transuranium nuclei are predicted with the cross sections at the order of ${10}^{\ensuremath{-}6}$ to $10\phantom{\rule{4pt}{0ex}}\ensuremath{\mu}\mathrm{b}$.

Quasifission barriers of heavy ion fusion reaction leading to the synthesis of superheavy nuclei 104 ≤ Z ≤ 126 with actinide targets

Quasifission barriers were studied in the superheavy region [Formula: see text] using different projectile-target combinations. The different entrance channels parameters on quasifission barriers give an insight into the formation of compound nuclei and quasifission process. The quasifission barriers are more systematic for [Formula: see text]. The effect of compound nucleus fissility [Formula: see text] and effective entrance channel fissility [Formula: see text] on quasifission barriers were investigated. The quasifission barriers are strongly influenced by [Formula: see text] and [Formula: see text] entrance channel parameters. The detailed investigations of entrance channel parameters on quasifission barriers provide a thorough understanding of compound nuclei formation in the superheavy element in the region [Formula: see text]. Eventually, this study helps in the selection of projectile-target combinations to synthesis of superheavy nuclei.

Modes of massive nucleon transfer appearing in quasifission processes for collisions of superheavy nuclei

Background: It is challenging to distinguish between fusion-fission and quasifission experimentally. To determine the characteristics of quasifission processes associated with dominant phenomena in heavy-ion collisions is important for estimating precisely the fusion cross section, which is relevant to the synthesis of new elements. We classified fusion-fission and quasifission processes theoretically in the past for an accurate assessment of the fusion cross section [Y. Aritomo and M. Ohta, Nucl. Phys. A 744, 3 (2004)]. However, no detailed analysis focused on each process was performed.Purpose: In this work, we aimed to analyze the dynamical characteristics of quasifission processes in terms of the Langevin equation model. We specify the quasifission processes, and analyze the scission configuration. Finally, we clarify the origin of several modes included in quasifission.Method: The calculation framework is the multidimensional dynamical model of nucleus-nucleus collisions based on the Langevin equations.Results: It is shown that several quasifission modes exist leading to different fragment deformations. The timescale of the quasifission process differs for several different modes. Each scission configuration and total kinetic energy also differ.Conclusions: The different quasifission modes are caused by the neck relaxation controlling the mass drift toward symmetry. This means that it is possible to discuss the time-dependent functional form of the neck parameter $\ensuremath{\epsilon}$ for the quasifission process in the framework of the dynamical model based on Langevin equations.

Search for possible fission modes at high excitation energies inFm254

Background: Shell effects have been found to influence both the compound nuclear fission (CNF) and quasifission processes. Besides quasifission processes, which fission modes remain active at excitation energy (${E}^{*}$) as high as 56 MeV should be investigated.Purpose: We investigate the signatures of fission modes in $^{254}\mathrm{Fm}$ populated by $^{16}\mathrm{O}\phantom{\rule{0.16em}{0ex}}+\phantom{\rule{0.16em}{0ex}}^{238}\mathrm{U}$ through the mass distribution (MD) and total kinetic energy distribution (TKED).Method: The mass--total kinetic energy distributions (M-TKED) of fission fragments of the reaction $^{16}\mathrm{O}\phantom{\rule{0.16em}{0ex}}+\phantom{\rule{0.16em}{0ex}}^{238}\mathrm{U}$ have been measured at two laboratory energies ${E}_{\text{lab}}=89$ and 101 MeV. The spontaneous fission (SF) of $^{254}\mathrm{Fm}$, one-dimensional (1D) fragment MD, and two-dimensional (2D) M-TKEDs of $^{16}\mathrm{O}\phantom{\rule{0.28em}{0ex}}+\phantom{\rule{0.28em}{0ex}}^{238}\mathrm{U}$ have been described by the multimodal random neck rupture (MM-RNR) model.Results: Channel probabilities and the characteristics of different fission modes are obtained and discussed in detail. The enhancement observed in the mass yield ($\ensuremath{\approx}{10}^{\ensuremath{-}2}\phantom{\rule{0.16em}{0ex}}%$) in the region 60--70 u for the light fragments at ${E}^{*}\ensuremath{\approx}45$ MeV goes away at the higher ${E}^{*}\ensuremath{\approx}56$ MeV. The heavy fragments of S1 and S2 modes are found to be associated with $Z\ensuremath{\approx}53$ and $Z\ensuremath{\approx}56$ shells, respectively. The slope of asymmetric to symmetric fission yields (when plotted against ${E}^{*}$) of $^{16}\mathrm{O}\phantom{\rule{0.16em}{0ex}}+\phantom{\rule{0.16em}{0ex}}^{238}\mathrm{U}$ is found to be similar to that of previously reported $^{18}\mathrm{O}\phantom{\rule{0.16em}{0ex}}+\phantom{\rule{0.16em}{0ex}}^{208}\mathrm{Pb}$.Conclusions: Analysis of 2D M-TKED data by the MM-RNR model reveals the possible presence of fission modes in $^{16}\mathrm{O}\phantom{\rule{0.16em}{0ex}}+\phantom{\rule{0.16em}{0ex}}^{238}\mathrm{U}$. The liquid-drop-like broad symmetric SL mode is found to peak at a lower energy than predicted by the Viola systematic, which matches mostly with that of Standard 2 mode. No signature of asymmetric quasifission is observed. The MD widths show a linear dependence with the measured energies.

Sensitive search for near-symmetric and super-asymmetric fusion-fission of the superheavy element Flerovium (Z=114)

Measurements of mass and angular distributions have been made for fission-like outcomes in reactions forming isotopes of flerovium (Z=114), using 48Ca, 50Ti, and 54Cr projectiles. The dominant fast quasifission process, which masks the presence of fusion-fission, has minimum yield at the most backward angles, where the sensitivity to fusion-fission is thus highest. In fitting the backward angle mass spectra, only weak evidence for a component of super-asymmetric fission was found, but a near-symmetric fission component was consistently required for the 48Ca + 244Pu reaction, giving upper limit to the fusion probabilities PCN of ∼10−2, ∼5 times lower than previous results. PCN for the 50Ti reaction was lower than 48Ca, whilst no evidence of fusion-fission was found for the 54Cr reaction.

Evidence of quasifission in the 180Hg composite system formed in the 68Zn + 112Sn reaction

For the 68Zn + 112Sn reaction the Coulomb parameter Z1Z2 is equal to 1500 that is close to the threshold value for the appearance of quasifission process. It was found that mass-energy distributions of the reaction fragments differ significantly from those obtained in the 36Ar + 144Sm reaction leading to the formation of the same composite system of 180Hg at similar excitation energies of about 50 MeV. In the case of the reaction with 68Zn ions, the mass distribution of fissionlike fragments has a wide two-humped shape with maximum yields at 70 and 110 u for the light and heavy fragments, respectively, instead of 80 and 100 u observed in the fission of 180Hg formed in the 36Ar + 144Sm reaction. The difference is explained by an unexpectedly large contribution (more than 70%) of quasifission in the case of the 68Zn + 112Sn reaction.

Effects of nucleus orientation on transfer process and production of unknown neutron-rich isotopes with Z=62–75 in Hg204+Th232 based on the dinuclear system model

Within the framework of the dinuclear system model, the contributions of the constituent parts of the driving potentials in different orientation configurations in the $^{86}\mathrm{Kr}+^{166}\mathrm{Er}$ reaction are investigated. The Coulomb potential plays a predominant role in the change of driving potential among different configurations with mass number ${A}_{1}=52--200$. In the region of ${A}_{1}<52$ and ${A}_{1}>200$, the effects of the nuclear potential increased significantly. This work also studied the multinucleon transfer process of $^{204}\mathrm{Hg}+^{232}\mathrm{Th}$ in tip-to-tip and side-to-side configurations to produce unknown neutron-rich isotopes with $Z=62--75$. In the $^{204}\mathrm{Hg}+^{232}\mathrm{Th}$ reaction, the tip-to-tip configuration accounts for the main contribution to produce unknown neutron-rich isotopes with $Z=62--75$ because of the ``inverse'' quasifission process. The optimal incident energy is 678.1 MeV. Considering the experimental conditions provided by the experiments, there are 29 unknown isotopes whose production rate is greater than one count per day. Especially, the production rates per day of $^{179}\mathrm{Ho}, ^{181,182}\mathrm{Er}, ^{182,183,184}\mathrm{Tm}, ^{186}\mathrm{Yb}, ^{189}\mathrm{Lu}, ^{191,192}\mathrm{Hf}$, and $^{195}\mathrm{Ta}$ are 21, 25, 13, 701, 1217, 29, 94, 29, 102, 29, and 20, respectively. The reaction of $^{204}\mathrm{Hg}+^{232}\mathrm{Th}$ at 678.1 MeV is a potential candidate to produce new neutron-rich nuclei with $Z=62--75$.

Probing entrance channel effects in fusion-fission dynamics through neutron multiplicity measurement of 208Rn

The pre- and post-scission neutron multiplicities are measured for the fission of 208Rn, populated with the reactions 30Si+178Hf and 48Ti+160Gd in the excitation energy range of 54.5 - 80.8 MeV. We found significant differences in the pre-scission neutron multiplicities of these two systems. Also, both the reactions exhibit an enhancement in the pre-scission multiplicity with respect to the existing data for the 16O+194Pt reaction populating 210Rn. The measured multiplicities are compared with the theoretical predictions obtained from the Langevin dynamical model for fission. Dynamical simulations are also performed to estimate the capture cross-sections. Contribution of the neutrons, emitted during the fusion process, is shown to be crucial in determining the neutron multiplicities for the present systems. Moreover, in case of the 48Ti+160Gd reaction, rapid quasi-fission dynamics prevents neutron emission from the thermalized target-projectile composite. The present measurement helps us to understand the relative importance of fusion and quasi-fission processes and their timescales depending on the entrance channel mass asymmetry.

Investigation of fusion probabilities in the reactions with Cr52,54, Ni64 , and Zn68 ions leading to the formation of Z=120 superheavy composite systems

Background: The formation of superheavy nuclei in fusion reactions is suppressed by a competing quasifission process. The competition between the formation of the compound nucleus and the quasifission depends strongly on the reaction entrance channel. Purpose: The investigation of fission and quasifission processes in the formation of Z=120 superheavy composite systems in the Cr52,54+Cm248 and Zn68+Th232 reactions, and their comparison with the Ni64+U238 reaction at energies in the vicinity of the Coulomb barrier. Methods: Mass-energy distributions of fissionlike fragments formed in the reactions Cr52,54+Cm248 and Zn68+Th232 at energies near the Coulomb barrier were measured using the double-arm time-of-flight spectrometer CORSET. Results: Capture cross sections for the reactions under investigation were measured. The most probable fragment masses and total kinetic energies as well as their variances in dependence on the interaction energy were studied for asymmetric and symmetric fragments. The fusion probabilities were estimated from the analysis of mass-energy distributions. Conclusions: The estimated fusion probability drops down by a factor of 103 in the Cr54+Cm248 reaction compared to the reactions of Ca48 ions with actinides. Among the studied reactions, the Cr54+Cm248 is the most favorable one for the production of the superheavy element with Z=120.1 MoreReceived 3 August 2020Accepted 2 September 2020DOI:https://doi.org/10.1103/PhysRevC.102.044605©2020 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasFissionLow & intermediate energy heavy-ion reactionsNuclear fusionPropertiesA ≥ 220Nuclear Physics

Systematic evidence for quasifission in Be9−, C12−, and O16 -induced reactions forming No258,260

Background: Cross sections for the formation of superheavy elements (SHE) by heavy ion fusion are suppressed by the competing quasifission process. This results in a fissionlike decay after capture but before formation of a compact compound nucleus. Fast quasifission is evident from very mass-asymmetric fission, focused in angle. In contrast, slow quasifission shows no significant mass-angle correlation, and a mass distribution peaked at symmetry. However, it shows angular distributions more anisotropic than those calculated for fission following fusion. Following fusion, low excitation energies should increase SHE survival through reduced competition from fission. However, in reactions with deformed actinide target nuclei, subbarrier fusion is highly suppressed by both fast and slow quasifission.Purpose: To investigate the threshold for quasifission by investigating signatures of slow quasifission in both fission angular and mass distributions, as a function of beam energy with respect to the capture barrier, for the projectiles $^{9}\mathrm{Be}$, $^{12}\mathrm{C},$ and $^{16}\mathrm{O}$ that form the neighboring compound nuclei $^{258,260}\mathrm{No}$.Methods: Fission mass and angular distributions have been measured from below to above-barrier energies using the kinematic coincidence method for the reactions $^{9}\mathrm{Be}+^{249}\mathrm{Cf}$, $^{12}\mathrm{C}+^{248}\mathrm{Cm}$, and $^{16}\mathrm{O}+^{244}\mathrm{Pu}$. Fission following transfer reactions can significantly contaminate fission events that follow capture, and must be rejected. Existing methods to reject transfer-induced fission have been refined to allow quantitative subtraction of the transfer fission component.Results: The capture-fission mass-angle distributions show no evidence for fast quasifission, as might be expected. However, measured fission fragment angular anisotropies are larger than transition state model (TSM) calculations for fusion fission. The deviations increase with larger projectile charge and for bombarding energies below the mean capture barrier energy. Even for the $^{9}\mathrm{Be}+^{249}\mathrm{Cf}$ reaction, the subbarrier angular anisotropy significantly exceeds the TSM calculation. Fission mass distributions measured at the same excitation energies also show a consistent dependence on the projectile charge.Conclusions: New refined analysis techniques have been developed to enable reliable separation of fission following capture from sequential fission following transfer reactions. For fission following capture at above-barrier energies, the $^{9}\mathrm{Be}$ angular anisotropies are close to the TSM predictions, supporting the validity of TSM calculations of fusion-fission for such heavy elements. At subbarrier energies the angular anisotropy data indicate a component of slow quasifission even for $^{9}\mathrm{Be}$, and a probability that increases rapidly with projectile charge. It is concluded that the probability of slow quasifission changes smoothly with projectile charge, having no sharp threshold.

An Approximation of the Synthesis Cross Section for the Unknown 126th Element via 58Ni + 251Cf and 64Zn + 248Cm Combinations

In this paper, we estimate the production cross section of the unknown super-heavy nuclei 309,312126 via 58Ni + 251Cf and 64Zn + 248Cm combinations by using approximation methods. For each reaction, the competition between compound nucleus (CN) formation and quasi-fission process is also analyzed. We found that the synthesis cross section for the 309126 isotope is about 3 fb, which is about 5 orders of magnitude higher than that for the 312126 nucleus. The results also suggest that a valley exists around the isotope with A = 313 in the production yields for the 126th element. Moreover, the synthesis of the 310–317126 isotopes is still a challenge for experimental techniques due to the small cross sections, which are less than 1 fb.

Systematic Study of Quasifission in 48Ca-induced reactions

The production of superheavy elements through the fusion of two heavy nuclei is severely hindered by the quasifission process, which results in the fission of heavy systems before an equilibrated compound nucleus (CN) can be formed. The heaviest elements have been synthesised using 48Ca as the projectile nucleus. However, the use of 48Ca in the formation of new superheavy elements has been exhausted, thus a detailed understanding of the properties that made 48Ca so successful is required. Measurements of mass-angle distributions allow fission fragment mass distribution widths to be determined. The effect of the orientation of prolate deformed target nuclei is presented. Closed shells in the entrance channel are also shown to be more important than the stability of the formed CN in reducing the quasifission component, with reduced mass widths for reactions with the closed shell target nuclei 144Sm and 208Pb. Comparison to mass widths for 48Ti-induced reactions show a significant increase in the mass width compared to 48Ca-induced reactions, highlighting the difficulty faced in forming new superheavy elements using projectiles with higher atomic number than 48Ca.

Features of the Fission Fragments Formed in the Heavy Ion induced $$^{32}\hbox {S}$$+$$^{197}\hbox {Au}$$ reaction near the interaction barrier

The features of fission fragments formed in the near barrier reaction $$^{32}\hbox {S}$$ + $$^{197}\hbox {Au}$$ ($$E^\mathrm{lab}_\mathrm{beam}=166\,\hbox {MeV}$$) are investigated. The measurement was performed at the ALTO facility of IPN Orsay, France, with the aim of clarifying the quantitative contribution of the quasi-fission process to the total fission events. The mass and total kinetic energy of the fission fragments were compared to the expectations of the liquid drop model, revealing an asymmetric fission component which may be traced back to a quasi-fission process mixed with the fusion–fission events. The $$\gamma $$-rays and neutrons measured in coincidence with the fission fragments were used to yield additional information for the discrimination of the two aforementioned mechanisms. All observed trends are consistent and fairly well reproduced by the statistical model.

Entrance-channel dynamics in the reaction 40Ca+208Pb

The entrance-channel dynamics including capture, fusion, and quasifission processes for the reaction $^{40}$Ca+$^{208}$Pb is investigated in the fully microscopic time-dependent Hartree-Fock (TDHF) theory.The calculations are performed in three-dimensional Cartesian coordinate without any symmetry restrictions, in which the full Skyrme energy functional SLy4d and SLy5 are adopted.We study the energy dependence of capture cross sections, and find that the experimental data are well reproduced by the TDHF calculations. Both fusion and quasifission events are observed in the reaction $^{40}$Ca+$^{208}$Pb. The contact time, mass and charge of quasifission fragments show a wide distribution in SLy4d compared withSLy5, implying that more nucleons are transferred in the SLy4d calculations.We find that the total kinetic energy of quasifission fragments in the TDHF calculations is distributed around Viola systematics,indicating that most of the relative kinetic energy is dissipated in quasifission dynamics.

Investigation of the synthesis of the unknown superheavy nuclei 309,312126

In this paper, we applied the method developed by Santhosh and Safoora in [Phys. Rev. C 94 (2016) 024623; 95 (2017) 064611] to theoretically investigate the fusion, evaporation-residue (ER) and fission cross-sections of the synthesis of the unknown superheavy [Formula: see text]126 nuclei produced by using the [Formula: see text]Ni + [Formula: see text]Cf and [Formula: see text]Zn + [Formula: see text]Cm combinations. The charge asymmetry, mass asymmetry and fissility of the DiNuclear System (DNS) in the synthesis of the mentioned combinations are also estimated. The calculated results show that the ER cross-sections for the synthesis of the [Formula: see text]126 nuclei are predicted to be much less than 1.0[Formula: see text]fb. In particular, it has been found that there may exist a valley of the ER cross-sections in the synthesis of a superheavy [Formula: see text] element, which produces the [Formula: see text]126 isotope. Subsequently, a model for the mass dependence of the ER cross-section in the synthesis of the [Formula: see text]126 isotopes has been proposed for the first time. On the other hand, the quasi-fission process strongly dominates over the fusion in the two concerned interacting systems. The present results, together with those reported in the previous studies, indicate that the investigated projectile–target combinations are not capable for the synthesis of the [Formula: see text]126 isotopes due to tiny fusion cross-sections (about 2–3[Formula: see text]zb), which go beyond the limitations of available facilities. Further studies are thus recommended to search for alternative interacting systems. In conclusion, this work provides useful information for the synthesis of the gap isotopes [Formula: see text]126, which have not been well studied up to date.

Fission mass distribution of various superheavy nuclei and related dynamical analysis

The fission mass distribution of Z=104-120 superheavy nuclei formed in 238U-induced reactions is investigated using the dynamical cluster decay approach. The cross-section for the formation of symmetric fragments with masses A2±20 of 274Hs⁎, 286Cn⁎, 286Fl⁎, and 302120⁎ nuclei are calculated over a wide energy spectrum by rationalizing the neck-length parameter (ΔR). The calculations are carried out by including the quadrupole (β2i)-deformation of the fragments using hot and cold optimum orientation approaches. Within hot orientation criteria, symmetric fission distribution is observed for 274Hs⁎ nucleus which becomes highly asymmetric in nature for 302120⁎ compound system. The lead (Pb)-peaks originating due to quasi-fission process start competing while going from 274Hs⁎ to 302120⁎ nucleus. Additionally, the role of cold orientation approach is also explored for these nuclei which show the opposite trend in the mass distribution while going from Z=108 to Z=120 superheavy system. Further, the fission and asymmetric quasi-fission cross-sections are predicted for various entrance channels i.e. 58Fe+244Pu, 54Cr+248Cm, and 50Ti+249Cf and compared with experimentally available data of 64Ni+238U reaction to identify the favorable projectile-target combination for the synthesis of Z=120 nucleus. The results show that because of larger fusion probability, 50Ti+249Cf reaction seems to provide a favorable option for the synthesis of Z=120 superheavy nucleus.