FastQSL: A Fast Computation Method for Quasi-separatrix Layers

TL;DR

FastQSL is an open-source GPU-accelerated method that significantly speeds up the computation of the squashing factor Q and twist number in 3D magnetic data, facilitating magnetic reconnection studies.

Contribution

It introduces a GPU-accelerated, adaptive step-size method for fast calculation of Q and twist number in 3D magnetic data cubes, improving efficiency over previous techniques.

Findings

Achieves 4.53 million Q values per second

Utilizes GPU hardware acceleration and adaptive tracing

Open source and user-friendly implementation

Abstract

Magnetic reconnection preferentially takes place at the intersection of two separatrices or two quasi-separatrix layers, which can be quantified by the squashing factor Q, whose calculation is computationally expensive due to the need to trace as many field lines as possible. We developed a method (FastQSL) optimized for obtaining Q and the twist number in a 3D data cube. FastQSL utilizes the hardware acceleration of the graphic process unit (GPU) and adopts a step-size adaptive scheme for the most computationally intensive part: tracing magnetic field lines. As a result, it achieves a computational efficiency of 4.53 million Q values per second. FastQSL is open source, and user-friendly for data import, export, and visualization.