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arXiv 1812.09522nucl-th
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如何产生新的超重核?

How to produce new superheavy nuclei?

K. Siwek-Wilczyńska, T. Cap, M. Kowal

摘要:

现有的实验设备限制了发现新核素的可能性,即那些合成的截面超过100 fb的核素,但未来的高电流加速器的前景可能会将这一限制降低两个数量级。因此,在目前的工作中,激发函数的聚变- $xn$蒸发反应通道诱导不仅由$^{48}Ca$,但也由较重的弹丸(通常导致较小的截面)的锕系元素的目标被计算的框架中的聚变-扩散(FBD)模型。在这种方法中,质子($pxn$)或α粒子($α$ $xn$)蒸发的通道首次被包括在去激发级联的第一步中。为了计算合成截面,使用华沙宏观-微观模型中以一致的方式计算的超重核的裂变势垒、基态质量、变形和壳效应等进入数据。FBD模型中唯一可调的参数是注入点距离$s_{inj}$,并采用了我们以前对Z=114-118的超重核合成实验截面分析中确定的值。本文给出了在原子序数112-120范围内合成选定的(截面在几个fb以上)新超晶格的激发函数。预计将观测到21种新的最重同位素。首次对FBD模型的不确定性进行了现实的讨论。

英文摘要:

Existing experimental facilities limit the possibilities for discovery of new nuclides to those synthesized with cross sections above 100 fb, but the perspectives for future high current accelerators could lower this limit by two orders of magnitude. Therefore, in the present work excitation functions for fusion-$xn$ evaporation reaction channels induced not only by $^{48}Ca$ but also by heavier projectiles (usually leading to smaller cross sections) on actinide targets were calculated in the framework of the fusion-by-diffusion (FBD) model. For the first time, in this approach, channels in which a proton ($pxn$) or alpha particle ($α$$xn$) is evaporated have been included in the first step of the deexcitation cascade. To calculate the synthesis cross sections entry data such as fission barriers, ground-state masses, deformations and shell effects of the superheavy nuclei calculated in a consistent way within the Warsaw macroscopic-microscopic model were used. The only adjustable parameter of the FBD model is the injection point distance $s_{inj}$ and the value determined in our previous analysis of experimental cross sections for the synthesis of superheavy nuclei of Z=114-118 has been used. Excitation functions for the synthesis of selected (cross section above a few fb) new superheavies in the range of atomic numbers 112-120 are presented. Observation of 21 new heaviest isotopes is predicted. A realistic discussion of the FBD model uncertainties is presented for the first time.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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