基于GPU加速的投影后变分壳模型计算  

GPU Accelerated Variation after Projection Calculation

作　　者：陆晓 连占江 高早春[1] LU Xiao;LIAN Zhanjiang;GAO Zaochun(Department of Nuclear Physics,China Institute of Atomic Energy,Beijing 102413,China)

机构地区：[1]中国原子能科学研究院核物理研究所,北京102413

出　　处：《原子能科学技术》2024年第2期272-278,共7页Atomic Energy Science and Technology

基　　金：国家自然科学基金(11975314,11575290);核数据重点实验室开放基金(JCKY2022201C158);国家财政部稳定支持研究经费(WDJC-2019-13,BJ20002501)。

摘　　要：为进一步拓展投影后变分(VAP)壳模型计算应用核区范围,需提升VAP的计算效率。为此,利用OpenACC并行编程指令,首次将VAP程序从传统的CPU平台移植到了高性能GPU计算平台上。在角动量投影的每个积分格点上实现了数目庞大的各独立转动矩阵元的GPU并行化计算。经验证,采用GPU加速后的VAP程序计算得到的结果与原来的OpenMP并行化程序计算得到的结果完全相同,而计算效率得到了数倍的提升。借助于GPU加速技术,首次计算了变形重核^(178)Hf的基带能谱,打开了VAP壳模型方法应用于变形稀土重核之门。The nuclear shell model has been very successful in describing various properties of nuclei,especially in the neighborhood of the closed shells,where the configuration space is usually small but good enough for the construction of the nuclear wave function.However,in the heavy deformed nuclear region,the configuration space is extremely huge.This makes it almost impossible to perform full shell model calculations.To avoid such difficulty,various approximated shell model methods have been developed.Among them,the variation after projection(VAP)method is an important one,in which the nuclear wave functions with good quantum numbers are sufficiently optimized.However,when the VAP method is applied to heavy deformed nuclei,the computational burden is still quite heavy.This is because there are a large number of matrix elements involving the angular momentum projection.All these projected matrix elements should be calculated by integrating the corresponding rotational matrix elements over the three Euler angles.Hence,accelerating the VAP calculation is crucial in extending the VAP application to heavy deformed nuclei,which is the purpose of the present paper.By analyzing the VAP code,it turns out that most of the computational cost is spent on evaluating the projected matrix elements.When the configuration space is huge,such computational cost for the projected matrix elements becomes extremely heavy.Fortunately,all the rotational matrix elements are independent of one another.This makes it very convenient in parallelizing the calculation of these rotational matrix elements.In general,the VAP calculations were accelerated on the traditional CPU platforms.But in recent years,with the rapid developments of the graphics processing unit(GPU),GPU becomes the first choice of modern high-performance computing.Here,by adopting the OpenACC parallel programming directives,the VAP code from the traditional CPU platform to the high-performance GPU platform has been successfully migrated.The calculations of a large amount of the i

关 键 词：壳模型 投影后变分 GPU OpenACC 

分 类 号：TL11[核科学技术—核能科学] O571.6[理学—粒子物理与原子核物理]