Influence of Isospin on Fission Cross Section as a Probe of Presaddle Nuclear Dissipation

TIAN Jian; YE Wei

doi:10.11804/NuclPhysRev.34.03.529

Langevin models that are coupled with particle emission are applied to calculate the drop of fission cross section caused by friction over its standard statistical-model value, σ_f^drop, as a function of excitation energy for three Bi nuclei with different isospins. We find that σ_f^drop become larger for ²⁰⁹Bi than for ²⁰²Bi and ¹⁹⁵Bi, indicating a greater sensitivity of fission cross section to friction for high-isospin ²⁰⁹Bi. These results suggest that, to more accurately determine the presaddle dissipation strength by measuring fission excitation functions, it is best to populate those compound systems with a high isospin. Furthermore, we analyze the data of fission excitation functions measured in p + ²⁰⁹Bi and p + ²⁰⁸Pb reactions, which yield high-isospin ²¹⁰Po and ²⁰⁹Bi systems, and extract a presaddle friction strength of (3-5)×10²¹ s^-1 by comparing Langevin simulations with these experimental data.

Influence of Isospin on Fission Cross Section as a Probe of Presaddle Nuclear Dissipation

Department of Physics, Southeast University, Nanjing 210096, China

Funds: National Natural Science Foundation of China (11575044)

Corresponding author: 10.11804/NuclPhysRev.34.03.529

Received Date: 2016-12-07

Rev Recd Date: 2017-03-30

Publish Date: 2017-07-18

Key words:

Abstract: Langevin models that are coupled with particle emission are applied to calculate the drop of fission cross section caused by friction over its standard statistical-model value, σ_f^drop, as a function of excitation energy for three Bi nuclei with different isospins. We find that σ_f^drop become larger for ²⁰⁹Bi than for ²⁰²Bi and ¹⁹⁵Bi, indicating a greater sensitivity of fission cross section to friction for high-isospin ²⁰⁹Bi. These results suggest that, to more accurately determine the presaddle dissipation strength by measuring fission excitation functions, it is best to populate those compound systems with a high isospin. Furthermore, we analyze the data of fission excitation functions measured in p + ²⁰⁹Bi and p + ²⁰⁸Pb reactions, which yield high-isospin ²¹⁰Po and ²⁰⁹Bi systems, and extract a presaddle friction strength of (3-5)×10²¹ s^-1 by comparing Langevin simulations with these experimental data.

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[1]	HILSCHER D, ROSSNER H. Ann Phys (Paris), 1992, 17, 471.
[2]	MUKUL I, NATH S, GOLDA K S, et al. Phys Rev C, 2015, 92, 054606.
[3]	BACK B B, BLUMENTHAL D J, DAVIDS C N, et al. Phys Rev C, 1999, 60, 044602; SANDAL R, BEHERA B R, SINGH V, et al. ibid, 2015, 91, 044621.
[4]	FRÖBRICH P, GONTCHAR I I. Phys Rep, 1998, 292, 131.
[5]	POMORSKI K, NERLO-POMORSKA B, SUROWIEC A, et al. Nucl Phys A, 2000, 679, 25.
[6]	NADTOCHY P N, ADEEV G D, KARPOV A V. Phys Rev C, 2002, 65, 064615.
[7]	YE W, YANG H W, WU F. Phys Rev C, 2008, 77, 011302(R).
[8]	WANG N, YE W. Phys Rev C,2013, 87, 051601(R).
[9]	JACQUET D, MORJEAN M. Prog Part Nucl Phys, 2009, 63, 155.
[10]	FABRIS D, VIESTI G, FIORETTO E, et al. Phys Rev Lett, 1994, 73, 2676.
[11]	AYYAD Y, BENLLIURE J, RODŔGUEZ-SÁNCHEZ J L, et al. Phys Rev C, 2015, 91, 034601.
[12]	YE W. Phys Rev C, 2009, 80, 011601(R).
[13]	YE W. Phys Lett B, 2007, 647, 118.
[14]	http://www.nndc.bnl.gov/exfor/exfor00.htm
[15]	LESTONE J P, MCCALLA S G. Phys Rev C, 2009, 79, 044611; Phys Rev Lett, 2008, 101, 032702.
[16]	KRAPPE H J, POMORSKI K. Theory of Nuclear Fission, Lecture Notes in Physics Vol. 838(Springer, Berlin, 2012).
[17]	FRÖBRICH P. Nucl Phys A, 2007, 787, 170c.
[18]	DAVIES K T R, SIERK A J, NIX J R. Phys Rev C, 1976, 13, 2385.
[19]	BRACK M, DAMGAARD J, JENSEN A S, et al. Rev Mod Phys, 1972, 44, 320.
[20]	KRAPPE H J, NIX J R, SIERK A J. Phys Rev C, 1979, 20, 992; SIERK A J. ibid, 1986, 33, 2039; MÖLLER P, MYERS W D, SWIATECKI W J. At Data Nucl Data Tables, 1988, 39, 225.
[21]	IGNATYUK AV, ITKIS M G, OKOLOVICH V N, et al. Sov J Nucl Phys, 1975, 21, 1185.
[22]	GONTCHAR I I, FRÖBRICH P, PISCHASOV N I, et al. Phys Rev C, 1993, 47, 2228.
[23]	BLANN M. Phys Rev C, 1980, 21, 1770.
[24]	IGNATYUK AV, Statistical Properties of Excited Nuclei (Moscow, 1983); IGNATYUK AV, IAEA report (Vienna:INDC (CCP) 233/L) (Engl. Transl.).
[25]	FRÖBRICH P. Nucl Phys A, 1992, 545, 854.
[26]	LAZAREV Y A, GONTCHAR I I, MAVLITOV N D. Phys Rev Lett, 1993, 70, 1220.
[27]	STRUMBERGER E, DIETRICH K, POMORSKI K. Nucl Phys A, 1991, 529, 522.
[28]	TILLACK G R, REIF R, SCHÜLKE A, et al. Phys Lett B, 1992, 296, 296.
[29]	YE W, SHEN W Q, LU Z D, et al. Z Phys A, 1997, 359, 385.
[30]	DIÓSZEGI I, SHAW N P, BRACCO A, et al. Phys Rev C, 2000, 63, 014611.
[31]	HOF G V, BACELAR J C S, DIÓSZEGI I, et al. Nucl Phys A, 1998, 638, 613.
[32]	BORUNOV M V, NADTOCHY P N, ADEEV G D.Nucl Phys A, 2008, 799, 56.
[33]	SCHMITT C, SCHMIDT K H, KELIĆ A, et al. Phys Rev C, 2010, 81, 064602; SCHMITT C, NADTOCHY P N, HEINZ A, et al. Phys Rev Lett, 2007, 99, 042701.
[34]	AYYAD Y, BENLLIURE J, RODŔGUEZ-SÁANCHEZ J L, et al. Phys Rev C, 2014, 89, 054610.
[35]	JURADO B, SCHMITT C, SCHMIDT K H, et al. Phys Rev Lett, 2004, 93, 072501.

Influence of Isospin on Fission Cross Section as a Probe of Presaddle Nuclear Dissipation

doi: 10.11804/NuclPhysRev.34.03.529

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