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Title: Formation of superheavy elements in cold fusion reactions

Abstract

We calculate the formation cross sections of transactinides (superheavy elements), as well as heavy actinides (No and Lr), which have been or might be obtained in fusion reactions with the evaporation of only one neutron. We use both more realistic fusion barrier and survival probability of the compound nucleus in comparison with the original phenomenological model [Phys. Rev. C 59, 2634 (1999)] that prompted the Berkeley experiment on the synthesis of a new superheavy element 118 [Phys. Rev. Lett. 83, 1104 (1999)]. Calculations are performed for asymmetric and symmetric target-projectile combinations and for reactions with stable and radioactive-ion beams. The formation cross sections measured at GSI-Darmstadt for transactinides and heavy actinides, as well as that for superheavy element 118 reported by the LBNL-Berkeley group, are reproduced within a factor of 2.4, on average. Based on the obtained relatively large cross sections, we predict that optimal reactions with stable beams for the synthesis of so far unobserved superheavy elements 119, 120, and 121 are {sup 209}Bi({sup 86}Kr, 1n){sup 294}119, {sup 208}Pb({sup 88}Sr, 1n){sup 295}120, and {sup 209}Bi({sup 88}Sr, 1n){sup 296}121, respectively. This is because of the magic of both the target and the projectile that leads to larger Q value and,more » consequently, lower effective fusion barrier with larger transmission probability. The same effect is responsible for relatively large cross sections predicted for the symmetric reactions {sup 136}Xe({sup 124}Sn, 1n){sup 259}Rf, {sup 136}Xe({sup 136}Xe, 1n){sup 271}Hs,{sup 138}Ba({sup 136}Xe, 1n){sup 273}110, and {sup 140}Ce({sup 136}Xe, 1n){sup 275}112. Although shell effects in the magic nuclei {sup 124}Sn, {sup 136}Xe, {sup 138}Ba, and {sup 140}Ce are not as strong as in {sup 208}Pb and {sup 209}Bi, they act on both the target and the projectile and lead to the prediction of measurable cross sections.« less

Authors:
Publication Date:
Sponsoring Org.:
(US)
OSTI Identifier:
40206175
Resource Type:
Journal Article
Journal Name:
Physical Review C
Additional Journal Information:
Journal Volume: 63; Journal Issue: 4; Other Information: DOI: 10.1103/PhysRevC.63.044607; Othernumber: PRVCAN000063000004044607000001; 047103PRC; PBD: Apr 2001; Journal ID: ISSN 0556-2813
Publisher:
The American Physical Society
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ACTINIDES; COLD FUSION; CROSS SECTIONS; EVAPORATION; FORECASTING; MAGIC NUCLEI; PROBABILITY; PROJECTILES; Q-VALUE; SYNTHESIS; TARGETS; TRANS 104 ELEMENTS

Citation Formats

Smolanczuk, Robert. Formation of superheavy elements in cold fusion reactions. United States: N. p., 2001. Web. doi:10.1103/PhysRevC.63.044607.
Smolanczuk, Robert. Formation of superheavy elements in cold fusion reactions. United States. https://doi.org/10.1103/PhysRevC.63.044607
Smolanczuk, Robert. 2001. "Formation of superheavy elements in cold fusion reactions". United States. https://doi.org/10.1103/PhysRevC.63.044607.
@article{osti_40206175,
title = {Formation of superheavy elements in cold fusion reactions},
author = {Smolanczuk, Robert},
abstractNote = {We calculate the formation cross sections of transactinides (superheavy elements), as well as heavy actinides (No and Lr), which have been or might be obtained in fusion reactions with the evaporation of only one neutron. We use both more realistic fusion barrier and survival probability of the compound nucleus in comparison with the original phenomenological model [Phys. Rev. C 59, 2634 (1999)] that prompted the Berkeley experiment on the synthesis of a new superheavy element 118 [Phys. Rev. Lett. 83, 1104 (1999)]. Calculations are performed for asymmetric and symmetric target-projectile combinations and for reactions with stable and radioactive-ion beams. The formation cross sections measured at GSI-Darmstadt for transactinides and heavy actinides, as well as that for superheavy element 118 reported by the LBNL-Berkeley group, are reproduced within a factor of 2.4, on average. Based on the obtained relatively large cross sections, we predict that optimal reactions with stable beams for the synthesis of so far unobserved superheavy elements 119, 120, and 121 are {sup 209}Bi({sup 86}Kr, 1n){sup 294}119, {sup 208}Pb({sup 88}Sr, 1n){sup 295}120, and {sup 209}Bi({sup 88}Sr, 1n){sup 296}121, respectively. This is because of the magic of both the target and the projectile that leads to larger Q value and, consequently, lower effective fusion barrier with larger transmission probability. The same effect is responsible for relatively large cross sections predicted for the symmetric reactions {sup 136}Xe({sup 124}Sn, 1n){sup 259}Rf, {sup 136}Xe({sup 136}Xe, 1n){sup 271}Hs,{sup 138}Ba({sup 136}Xe, 1n){sup 273}110, and {sup 140}Ce({sup 136}Xe, 1n){sup 275}112. Although shell effects in the magic nuclei {sup 124}Sn, {sup 136}Xe, {sup 138}Ba, and {sup 140}Ce are not as strong as in {sup 208}Pb and {sup 209}Bi, they act on both the target and the projectile and lead to the prediction of measurable cross sections.},
doi = {10.1103/PhysRevC.63.044607},
url = {https://www.osti.gov/biblio/40206175}, journal = {Physical Review C},
issn = {0556-2813},
number = 4,
volume = 63,
place = {United States},
year = {Sun Apr 01 00:00:00 EST 2001},
month = {Sun Apr 01 00:00:00 EST 2001}
}