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Production of 155Tb radioisotope for medical purposes is still a challenge. In this regard the present study has been done using 16O beam and 146Nd target within the 3–7 MeV/nucleon energy range. The γ-ray spectrometry has been used to identify the residues produced in the reaction. The EF measurements have been done and cross-sections of 155Tb have been reported and compared with the theoretical model code PACE 4. A strong indication of the occurrence of incomplete fusion has been realized within the energy range considered. The highest cross-section of 124 ± 12 mb has been obtained at Elab 101.7 ± 0.5 MeV. [ABSTRACT FROM AUTHOR]

The fusion excitation functions of evaporation residues, populated through complete fusion and/or incomplete fusion, were measured in the 18 O+ 146 Nd system at an incident beam energy of ≈ 3–7 MeV/nucleon. These results were then compared with those obtained from the previously reported 16 O+ 148 Nd system. This comparison is particularly relevant since both systems lead to the population of the same compound nucleus, 164 Er*, in the case of complete fusion, and the same intermediate composite system, 160 Dy*, in the case of incomplete fusion. Significant enhancements in the measured excitation functions of evaporation residues populated via α -emitting channels indicate the population of such residues via incomplete fusion in addition to complete fusion. Further, a comparison of the measured data for 18 O+ 146 Nd and 16 O+ 148 Nd systems shows interesting results. The complete fusion and incomplete fusion cross-sections, reduced by three different procedures, are found to satisfactorily match each other, despite the major difference in the α - breakup threshold values of the projectiles 18 O (6.23 MeV) and 16 O (7.16 MeV). The effect of different α -breakup threshold values of the projectiles 18 O and 16 O was not observed in the comparison of incomplete fusion data for the systems 18 O+ 146 Nd and 16 O+ 148 Nd. This may be attributed to the fact that the residues populated in the exit channel are emitted from the same intermediate composite system 160 Dy* and also there is a high resemblance in the entrance channel mass asymmetry and other structural properties of these systems. [ABSTRACT FROM AUTHOR]

The present work aims to differentiate the contributions of complete fusion (CF) and incomplete fusion (ICF) components by the measurement and analysis of the forward recoil range distribution of 20Ne projectile with 159Tb target nucleus. The recoil catcher technique has been employed for the identification of residues populated in the collision of 20Neion beam at projectile energy -8.2 MeV per nucleon. The result obtained from the study suggests that the complete fusion reaction occurs with complete momentum transfer, which leads to large recoil ranges of the reaction products. However, the presence of incomplete fusion, resulting from the break-up of 20Ne into 16O + 4He, 12C+ 8Be, and/or 8Be + 12C, involves partial momentum transfer, leading to small recoil ranges where one of the fragments undergoes fusion with the 159Tb target nucleus. Moreover, upon analyzing the data, the ICF fraction (FICF) has been estimated and compared with literature data as a function of various entrance channel parameters, namely Mass-asymmetry (µMA), Coulomb factor (ZPZT), Deformation parameter (β2) and ZPZT-2. The outcomes offer valuable insights into the entrance channel parameters that influence incomplete fusion dynamics. Additionally, a new entrance channel parameter called Zeta (ζ) was introduced to investigate the combined effect of µMA and ZPZT. [ABSTRACT FROM AUTHOR]

We discuss our present understanding of the incomplete fusion (ICF) reaction dynamics, the excitation function of six evaporation residues (ERs) have been measured in 16O + 156Gd reaction at projectile energy range, E/A ~ 4.3-6.3 MeV/Nucleon. Some of the ERs are produced directly & indirectly (i.e. through pre-cursor), the pre-cursor contributions have been separated out from the measured cumulative cross-section with the help of Cavinato et al.1. After correcting the pre-cursor contribution, the independent yield has been compared with the statistical model code PACE-22, which describes the fusion reaction cross section. In order to optimize the parameter of the code PACE-2 that reproduces the cross section of all the complete fusion (CF) channels like xn and/or pxn-channels. Using the same set of input parameters, cross section of the ERs populated via incomplete fusion (ICF) channels have been measured. The enhancement in the measured cross section of the ERs populated via ICF channels over the PACE-2 prediction have been measured, which indicates the occurrence of the break-up of projectile 16O into (12C+a) and/or (8Be+2a) leading to ICF reaction dynamics. [ABSTRACT FROM AUTHOR]

Measurements of excitation functions were done for the evaporation residues populated in 14 N + 124 Sn system at low energy. The present analysis shows the appearance of incomplete fusion by the breakup of non- α cluster structured projectile 14 N into α + 10 B . A correlation between the combined effects of total asymmetry and Z P Z T has been studied through three new parameters total asymmetry ( S TAS ), Coulomb asymmetry parameters; Z P Z T / S TAS and Z P Z T. S TAS . These new parameters were found more sensitive and effective to encounter the combined effects of coulomb interactions and entire asymmetry effect of the system on incomplete fusion dynamics. The complete fusion and total fusion cross-sections of two systems 14 N + 124 Sn and 16 O + 124 Sn have been reduced using two different standard reduction procedures, which shows that the incomplete fusion probability for reactions induced by projectile 16 O is generally larger than 14 N induced reactions. The experimental fusion functions are found to be suppressed as compared to universal fusion function for systems 14 N + 124 Sn and 16 O + 124 Sn . The different values of suppression factor for projectiles 14 N and 16 O indicate that the probability of α -breakup is different for these projectiles. Further, the total fusion functions for systems 14 N + 124 Sn and 16 O + 124 Sn agree well with the universal fusion function. However, the present results clearly show that the shell closure of nuclei also affect the low energy incomplete fusion dynamics along with the structure of projectile. [ABSTRACT FROM AUTHOR]

Forward recoil range distribution of evaporation residues (ERs) populated through complete fusion (CF) and incomplete fusion (ICF) dynamics in 1 6 O + 1 2 4 Sn system have been measured. Different full and partial linear momentum transfer components have been observed. The results indicate the occurrence of ICF involving break-up of 1 6 O into 4He + 1 2 C and 8Be + 8Be. However, the present data shows that the ERs are populated through both CF and ICF. A systematic study was performed which shows that the ICF fraction rises exponentially with the established entrance channel parameters and their various combinations. Moreover, these present results clearly show that Z P Z T. μ E C A S is able to explain the ICF dynamics more conclusively than combined parameter Z P Z T. β 2 for the systems having spherical or slightly deformed target. Further, the dependence of ICF dynamics on target structure has also been studied through a new parameter N / Z of the target. The parameter N / Z is directly associated with the target structure and has been found more effective and sensitive than existing parameters to investigate the target structure effect on ICF dynamics. Thus, the present observations suggest that N / Z ratio of the target should also be considered as an important entrance channel parameter which strongly affects the ICF dynamics. [ABSTRACT FROM AUTHOR]

Measurements of the forward recoil ranges of the evaporation residues 159,158Er (xn), 160g,159Ho (pxn), 157,155Dy (αxn) and 155Tb (αpxn) formed in the interaction of 16O with 148Nd at energy ≈ 5.8 MeV/nucleon have been done. Measured forward recoil range distributions of these evaporation residues show population of several incomplete fusion channels in addition to complete fusion. The entire and incomplete linear momentum transfers inferred from these recoil range distributions have been used to identify the evaporation residues populated through complete and incomplete fusion dynamics. The forward recoil range distributions of evaporation residues populated via α-emission channels show two composite peaks, one associated with complete fusion and other peak corresponds to the incomplete fusion. Further, the relative contributions of CF and/or ICF components have also been separated out from the present measurements. The contribution of ICF channels has been found to be ≈ 9 % of total fusion. The present results clearly indicate the presence of break-up of the projectile 16O into 12C + α at low projectile energy. [ABSTRACT FROM AUTHOR]

The present work has been carried out to understand the dynamics of incomplete fusion reactions and its dependency on various entrance channel parameters at low projectile energy. The excitation functions of evaporation residues 137,135,133Ce (xn), 133La (pxn), 133m,131m,129Ba (αxn), 135m,132Cs (αpxn), 131mXe (2αxn) and 131I (2αpxn) have been measured for the system 16O + 124Sn at projectile energy ≈3-7 MeV/nucleon. The analysis of measured excitation functions have been done within the framework of statistical model code PACE-4. The incomplete fusion fraction (FICF) has been deduced from present measurements for the study of systematics. Two new combined parameters (1-β2/ZPZT) and (1-β2/μASEC) have been introduced as a combination of the entrance channel parameters mass-asymmetry (μASEC), coulomb factor (ZPZT) and deformation parameter (β2) of target. The present study shows that incomplete fusion fraction decreases indepndently for diffrent projectiles with increase in these parameters. These combined parameters can explain the characteristics of incomplete fusion dynamics more clearly as compared to individual entrance channel parameters at these energies. These present results suggest that the incomplete fusion dynamics can be better explained by combined effects of entrance channel parameters than that of their individual effects. [ABSTRACT FROM AUTHOR]

More complex and interesting phenomenon of incomplete fusion (ICF) reactions induced by 20Ne on 159Tb have been measured at several beam energies range of 4.3 - 8.2 MeV/A by using catcher foil technique followed by the gamma-ray spectrometry. The cumulative cross-sections of evaporation residues produced in above reaction have been measured and deduced independent cross-sections have been compared with statistical model based computer code PACE-2. The complete fusion (CF) channels pxn agrees well with PACE-2 predictions after the subtraction of precursor contribution. The alpha emission products show higher cross-section than that predicted by the complete fusion product, which is attributed to the presence of incomplete fusion of projectile with target at lower energies. This enhancement in the measured cross-section is attributed to the fact that these residues are formed not only by complete fusion but also through the ICF of 20Ne into α clusters, i.e., 20Ne into 16O+α and/or 12C+2α etc. For the better understanding of ICF, the incomplete fusion fraction has also been deduced and its sensitivity with various channel parameters like projectile energy, entrance channel mass-asymmetry, α-Q value, Coulomb effect (ZPZT), deformation parameter (β2) have been observed. [ABSTRACT FROM AUTHOR]

Excitation functions for the evaporation residues 161,159,158Er (xn), 161-159Ho (pxn), 157,155Dy (αxn) and 155Tb (αpxn) populated via complete and/or incomplete fusion in system 16O + 148Nd system at low projectile energies ≈3−7 MeV/A have been measured. In these measurements recoil catcher activation technique followed by offline γ -ray spectrometry has been used. The total measured excitation functions of the evaporation residues 161,159,158Er (xn) and 161-159Ho (pxn) produced through xn and pxn channels are found to be well reproduced with the total PACE-4 predictions after subtraction of precursor contributions. A significant enhancement in the total measured excitation functions over their total theoretical predictions for the evaporation residues 157,155Dy (αxn) and 155Tb (αpxn) produced in α-emitting channels has been observed. This enhancement is attributed due to the presence of break-up of the incident projectile 16O into α clusters (i.e., break-up of 16O into 12C + α) and incomplete fusion of projectile 16O with target 148Nd at these low energies. A comparison of the present data with earlier measurements indicates that the ICF probability depends on Coulomb factor (ZPZT) along with target deformation ( β2T ). However, more systematic study on same Z spherical and deformed targets with same projectile at low energy is required to understand the role of target deformation on incomplete fusion dynamics. [ABSTRACT FROM AUTHOR]

Continuous efforts are being made to comprehend the process of low energy incomplete fusion (ICF) reaction dynamics. The lack of proper theoretical model below 8 MeV/nucleon, which could reproduce the experimentally measured ICF data satisfactorily, makes it the topic of great interest. Another important motivation is to look for some systematic dependence of ICF on various entrance channel parameters. Keeping the aforementioned aspects into consideration, the experiment has been performed using 12C ion beam on 165Ho target by employing the stacked foil activation technique. The experimentally measured cross sections of the populated evaporation residues have been measured and compared with the complete fusion code PACE4. It has been observed that the measured cross sections for evaporation residues populated via xn and pxn emission channels are well reproduced by PACE4 code. However, in the α-emission channels (observed in the projectile break-up), the significant enhancement in the measured cross sections over PACE4 predictions is observed which is accredited to ICF process. In the present work, ICF dependence on the target deformation and the combined parameter μ*ZpZt* (1-β2) has been studied. The ICF fraction has also been found sensitive to projectile Qα-value. [ABSTRACT FROM AUTHOR]

In the present work, the break-up fusion or incomplete fusion (ICF) process has been studied from the forward recoil range distribution measurement for 16O + 175Lu system at ≈ 96 MeV energy. The measured forward recoil range distributions are analyzed in the framework of code SRIM. The present analysis shows clearly the role of linear momentum transfer and also the break-up of projectile 16O into its fragments (12C + 4He and/or 8Be + 8Be). Any systematic trend is not observed with the target deformation parameter (β2) dependent study of ICF. It is observed that projectile structure also affects the ICF dynamics. The projectile α-Q-value is found to be a suitable parameter which explains effectively the observed projectile structure effect on ICF. [ABSTRACT FROM AUTHOR]

Transition intensity distributions for evaporation residues 169-166 Lu(xn), 168, 167Yb(pxn), 168, 165, 164 Tm (α xn) , 165 Er (α p 3 n) , 162 Ho (2 α 3 n) and 163-160 Dy (2 α pxn) populated through complete and incomplete fusion in the 19F + 154Sm system have been measured. The feeding intensity patterns of incomplete fusion channels are found to have a narrow range feeding only for high spin states, while complete fusion channels are strongly fed over a broad spin range and widely populated. A comparative study of present measurements shows the effect of projectile deformation along with entrance channel mass asymmetry. Further, comparison of present results with the literature suggests that the mean input angular momentum values are relatively larger in the collision of a deformed projectile with a deformed target than that in the collision of a spherical projectile with a deformed target at the same relative velocity of incident projectile. However, ICF dynamics has also been found to be influenced by relative orientations (i.e. tip-tip or side-side) of the interacting partners. It means that there is more involvement of peripheral collisions between the deformed-deformed nuclei. The present analysis also shows that there is a projectile dependence on ICF dynamics, which would require more investigation. Present results of mean input angular momenta for different evaporation residues highlight the role of projectile deformation and orientations of interacting nuclei in the dynamics of incomplete fusion as well as complete fusion. [ABSTRACT FROM AUTHOR]

To understand the low-energy incomplete fusion (ICF) reaction dynamics, the excitation function measurements of 12C+165Ho system has been performed in the energy region of ≈ 4-7 MeV/nucleon, by employing the stacked foil activation technique. The cross sections of the measured evaporation residues are compared with the theoretical predictions of statistical model code PACE4, which takes into account only the complete fusion (CF) reaction cross section. It is observed that residues populated via xn and pxn channels are in good agreement with the PACE4 predictions, implying that these residues are populated via CF process. However, in the case of α-emission channels a significant enhancement from the PACE4 predictions is observed even after the deduction of precursor contribution, which is accredited to ICF process. The projectile break-up probability is found to increase with increment in the incident projectile energy. Further, the dependence of incomplete fusion dynamics on entrance channel parameters like mass asymmetry, Coulomb effect (ZPZT), and projectile Qα value is systematically studied. The present results reveal that a single entrance channel parameter does not oversee the ICF reaction dynamics but have varying contributions depending upon the projectile-target combination. Moreover, the effect of projectile break-up on complete fusion cross section at energies above the Coulomb barrier is also studied. The suppression in fusion cross section is observed when compared with the universal fusion function. [ABSTRACT FROM AUTHOR]

An attempt has been made to provide crucial information about the dependence of incomplete-fusion dynamics on various entrance channel parameters below 8 MeV/nucleon energy. The forward recoil range distributions of several evaporation residues produced in the 13C + 175Lu system have been measured at ≈ 88 -MeV energy and examined in the framework of the code SRIM. Owing to the fractional linear momentum transfer from the projectile to the target nucleus, incomplete-fusion (ICF) products are observed to be trapped at lower cumulative thickness than that of complete fusion products. In order to study the incomplete-fusion behavior with various entrance channel parameters, the incomplete-fusion fraction (FICF) has also been deduced and compared with those obtained for the systems available in the literature. The reinvestigation of the Coulomb factor (ZPZT) dependence of incomplete fusion indicates that it is somehow projectile structure dependent. No systematic trend is observed with the target deformation parameter (β2) dependent study of ICF. A systematic linear growth in the incomplete-fusion probability function (FICF) is observed with increasing the parameters ZP ZTβ2 and ZPZT/(1-β2), but separately for α - and non- α -cluster structured projectiles with different targets. The present findings explore the role of Coulomb interaction on ICF dynamics more effectively. Moreover, the projectile α-Q value is found to be a suitable parameter which explains effectively the observed trend in the study of ICF with the above-mentioned parameters. The incomplete-fusion existence below critical angular momentum (ℓcrit), i.e., ℓ ≤ ℓcrit, is also observed for the present 13C + 175Lu system. [ABSTRACT FROM AUTHOR]

The disentangling of incomplete fusion dependence on various entrance channel parameters has been made from the forward recoil range distribution measurement for the 12C+175Lu system at ≈88 MeV energy. It gives the direct measure of full and/or partial linear momentum transfer from the projectile to the target nucleus. The comparison of observed recoil ranges with theoretical ranges calculated using the code SRIM infers the production of evaporation residues via complete and/or incomplete fusion process. Present results show that incomplete fusion process contributes significantly in the production of αxn and 2αxn emission channels. The deduced incomplete fusion probability (FICF) is compared with that obtained for systems available in the literature. An interesting behavior of FICF with ZPZT is observed in the reinvestigation of incomplete fusion dependency with the Coulomb factor (ZPZT), contrary to the recent observations. The present results based on (ZPZT) are found in good agreement with recent observations of our group. A larger FICF value for 12C induced reactions is found than that for 13C, although both have the same ZPZT. A nonsystematic behavior of the incomplete fusion process with the target deformation parameter (β2) is observed, which is further correlated with a new parameter (ZPZT.β2). The projectile α -Q-value is found to explain more clearly the discrepancy observed in incomplete fusion dependency with parameters (ZPZT) and (ZPZT.β2). It may be pointed out that any single entrance channel parameter (mass-asymmetry or (ZPZT) or β2 or projectile α-Q-value) may not be able to explain completely the incomplete fusion process. [ABSTRACT FROM AUTHOR]

The emission of auger electrons from 161Ho makes it as a potential candidate for Auger electronic therapy. Despite several methods for its production are proposed, it remains scarcely available. Most of the direct methods using low-energy protons and deuterons beams result in a high content of radionuclidic impurities. Hence, an alternative method for the production of 161Ho has been proposed. Experimental excitation functions in 16O induced reactions were measured with the activation method in the 69–100 MeV energy range on 154Sm targets. To measure the cross-section data for producing 161Ho, the stacked foil irradiation method along with high-resolution gamma-ray spectrometry was employed. The experimental data are compared with results of PACE4 and EMPIRE-3.2.2 theoretical codes. It was observed that the 161Ho radioisotope is produced via incomplete fusion. The production route suggested has no impurities of Holmium isotopes. [ABSTRACT FROM AUTHOR]

The forward recoil range distributions and angular distributions of several evaporation residues produced via complete and incomplete fusion (ICF) dynamics in 16O+148Nd system at energy ≈6 MeV/nucleon were measured. The measured forward recoil range distributions of various reaction products show the presence of incomplete fusion components apart from complete fusion. Full and partial linear momentum transfer components of reaction products were found in the interaction of 16O with 148Nd. These results were also confirmed by the measurements of angular distributions of evaporation residues. The measured angular distributions of the evaporation residues populated through complete and incomplete fusion channels were found to be distinctly different. The evaporation residues populated via complete fusion channels were trapped in the narrow angular zone as compared to incomplete fusion channels. A systematic study of the dependence of incomplete fusion dynamics on well-known entrance channel parameters shows that the incomplete fusion fraction grows exponentially with mass asymmetry (μASEC), Coulomb factor (ZPZT) and α-Q value of the projectile. The present observations suggest an exponential rise of ICF fraction with entrance channel parameters in contrast with the linear pattern reported in some earlier measurements. Further, the correlation of incomplete fusion fraction with the structure of target (T) was investigated employing four different parameters viz. deformation parameter (βT2), interaction radius (RT), deformation length (βT2RT) and excess of neutrons (N-Z)T in the target. In the present study, the ICF fraction was found to rise exponentially with these parameters, independently for different projectiles. The three parameters βT2, βT2RT, and (N-Z)T were found more sensitive and effective to investigate the entire picture about the influence of projectile and target deformation along with their relative orientations on incomplete fusion dynamics at low projectile energy. Moreover, the interaction radius of target (RT) is suitable to explain the characteristics of ICF dynamics in the spherical-spherical collisions. These present results show that incomplete fusion dynamics is strongly affected by the structure of projectile along with the target. [ABSTRACT FROM AUTHOR]

A study of low-energy incomplete fusion was done by the measurements of excitation functions of evaporation residues produced in the 16O+148Nd system at energies ≈4-7 MeV/nucleon. The stacked foil activation technique using offline γ-ray spectrometry was employed. Significant enhancements were found in the measured cross sections from the theoretical predictions of pace-4 for the evaporation residues populated through α-emission channels. This enhancement is attributed to incomplete fusion (ICF) of 16O with 148Nd. The comparison of present work with literature data shows that the ICF probability increases exponentially with existing entrance channel parameters. The dependence of ICF dynamics on target deformation was investigated using deformation parameter (βT2), deformation length (βT2RT) and neutron excess (N-Z)T of the target. The present analysis indicates that the ICF fraction rises exponentially with βT2, βT2RT, and (N-Z)T. These results show that the ICF fraction follows a systematic exponential pattern rather than a simple linear growth with various entrance channel parameters reported in the literature. However, this study also suggests that the ICF dynamics is strongly influenced by the structure of projectile along with that of the target. Further, the role of deformation parameters on incomplete-fusion dynamics was also investigated through the method of universal fusion function. Analysis of the present data indicates that the experimental fusion functions are suppressed with different factors depending on deformation of the target nuclei. These suppressions are removed by including incomplete-fusion cross sections in the fusion function calculations. The average value of experimental fusion functions deviates from the universal fusion function for deformed targets. However, the average value of the total fusion function for deformed targets shifts towards the average value of the universal fusion function. The present study shows that the effect of target deformation plays an important role in affecting the ICF dynamics, along with various entrance channel parameters for different systems. [ABSTRACT FROM AUTHOR]