Abstract
The fission decay of highly neutron-rich uranium isotopes is investigated which shows interesting new features in the barrier properties and neutron emission characteristics in the fission process. 233U and 235U are the nuclei in the actinide region in the beta stability valley which are thermally fissile and have been mainly used in reactors for power generation. The possibility of occurrence of thermally fissile members in the chain of neutron-rich uranium isotopes is examined here. The neutron number N = 162 or 164 has been predicted to be magic in numerous theoretical studies carried out over the years. The series of uranium isotopes around it with N = 154–172 are identified to be thermally fissile on the basis of the fission barrier and neutron separation energy systematics; a manifestation of the close shell nature of N = 162 (or 164). We consider here the thermal neutron fission of a typical representative 249U nucleus in the highly neutron-rich region. Semiempirical study of fission barrier height and width shows that 250U nucleus is stable against spontaneous fission due to increase in barrier width arising out of excess neutrons. On the basis of the calculation of the probability of fragment mass yields and the microscopic study in relativistic mean field theory, this nucleus is shown to undergo exotic decay mode of thermal neutron fission (multi-fragmentation fission) whereby a number of prompt scission neutrons are expected to be simultaneously released along with the two heavy fission fragments. Such properties will have important implications in stellar evolution involving r-process nucleosynthesis.
Similar content being viewed by others
References
M Thoennessen, Rep. Prog. Phys. 67, 1187 (2004)
W Nazarewicz, Nucl. Phys. A630, 239c (1998)
P G Hansen, Nucl. Phys. A630, 285c (1998)
K Rykaczewski, R Grzywacz, M Lewitowicz and M Pfutzner, Nucl. Phys. A630, 307c (1998)
W M Howard and P Möller, At. Data Nucl. Data Tables 25, 219 (1980)
S Cwiok, J Dobaczewski, P-H Heenen, P Magierski and W Nazarewicz, Nucl. Phys. A611, 211 (1996)
Z Patyk and A Sobiczewski, Nucl. Phys. A533, 132 (1991)
P Möller and J R Nix, At. Data Nucl. Data Tables 39, 213 (1988)
G Münzenberg and S Hofmann, Heavy elements and related new phenomena edited by W Greiner and R K Gupta (World Scientific, 1999), Ch. 1, p. 9
Yu Ts Oganessian, Heavy elements and related new phenomena edited by W Greiner and R K Gupta (World Scientific, 1999) Ch. 2, p. 43
P Möller, R J Nix, W D Myers and W J Swiatecki, At. Data Nucl. Data Tables 59, 185 (1995)
P Möller, R J Nix and K-L Kratz, At. Data Nucl. Data Tables 66, 131 (1997)
G Audi, A H Wapstra and C Thibault, Nucl. Phys. A729, 337 (2003)
M S Samant, R P Anand, R K Choudhury, S S Kapoor and D M Nadkarni, Phys. Rev. C51, 3127 (1995)
M S Samant, R P Anand, R K Choudhury, S S Kapoor, K Kumar, D M Nadkarni and A Saxena, Pramana — J. Phys. 40, 299 (1993)
R G Thomas et al, Phys. Rev. C75, 024604 (2007)
B S Meyer, W M Howard, G J Mathews, K Takahashi, P Möller and G A Leander, Phys. Rev. C39, 1876 (1989)
M Del Estal, M Centelles, X Viñas and S K Patra, Phys. Rev. C63, 024314 (2001); Phys. Rev. C63, 044321 (2001)
T Sil, S K Patra, B K Sharma, M Centelles and X Viñas, Phys. Rev. C69, 044315 (2004)
R Vandenbosch and J R Huizenga, Nuclear fission (Academic Press, inc., USA, 1973) Ch. III, p. 45
N E Holden and D C Hoffman, Pure Appl. Chem. 72, 1525 (2000)
P Madler, Z. Phys. A321, 343 (1985)
S K Patra, M Del Estal, M Centelles and X Viñas, Phys. Rev. C63, 024311 (2001)
C J Horowitz and B D Serot, Nucl. Phys. A368, 503 (1981)
G A Lalazissis, J König and P Ring, Phys. Rev. C55, 540 (1997)
R C Nayak and L Satpathy, At. Data Nucl. Data Tables 73, 213 (1999)
L Satpathy, J. Phys. G13, 761 (1987)
R C Nayak, V S Uma Maheswari and L Satpathy, Phys. Rev. C52, 711 (1995)
L Satpathy, V S Uma Maheswari and R C Nayak, Phys. Rep. 319, 85 (1999)
L Satpathy and R C Nayak, J. Phys. G24, 1527 (1998)
L Satpathy and S K Patra, J. Phys. G30, 771 (2004); Nature News India (October 2004)
L Satpathy and S K Patra, Nucl. Phys. A722, 24c (2003)
P Arumugam, B K Sharma, S K Patra and Raj K Gupta, Phys. Rev. C71, 064308 (2005)
B K Sharma, P Arumugam, S K Patra, P D Stevenson, Raj K Gupta and W Greiner, J. Phys. G32, L1 (2006)
Raj K Gupta, S K Patra, P D Stevenson and Walter Greiner, Int. J. Mod. Phys. E16, 1721 (2007)
B D Serot and J D Walecka, Adv. Nucl. Phys. 16, 1 (1986)
Y K Gambhir, P Ring and A Thimet, Ann. Phys. (N.Y.) 198, 132 (1990)
Y Sugahara and H Toki, Nucl. Phys. A579, 557 (1994)
S Gmuca, Nucl. Phys. A547, 447 (1992)
P K Panda, S K Patra, J Reinhardt, J A Maruhn, H Stöcker and W Greiner, Int. J. Mod. Phys. E6, 307 (1997)
D G Madland and R J Nix, Nucl. Phys. A476, 1 (1988)
S K Patra, C-L Wu, C R Praharaj and R K Gupta, Nucl. Phys. A651, 117 (1999)
M K Pal, Nucl. Phys. A556, 201 (1993)
M Bender, P-H Heenen and P-G Reinhard, Rev. Mod. Phys. 75, 121 (2003)
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Satpathy, L., Patra, S.K. & Choudhury, R.K. Fission decay properties of ultra neutron-rich uranium isotopes. Pramana - J Phys 70, 87–99 (2008). https://doi.org/10.1007/s12043-008-0007-2
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12043-008-0007-2