The variability in multi-pulse gamma-ray bursts (GRBs) may help to reveal the mechanism of underlying processes from the central engine. To investigate whether the self-organized criticality (SOC) phenomena exist in the prompt phase of GRBs, we statistically study the properties of GRBs with more than 3 pulses in each burst by fitting the distributions of several observed physical variables with a Markov Chain Monte Carlo approach, including the isotropic energy E_iso, the duration time T, and the peak count rate P of each pulse. Our sample consists of 454 pulses in 93 GRBs observed by the CGRO/BATSE satellite. The best-fitting values and uncertainties for these power-law indices of the differential frequency distributions are: \(\alpha_E^d=1.54\pm0.09, \alpha_T^d=1.82\pm_{0.15}^{+0.14}\;and\;\alpha_P^d=2.09_{-019}^{+0.18}\), while the power-law indices in the cumulative frequency distributions are: \(\alpha_E^c=1.44_{-0.10}^{+0.08}, \alpha_T^c=1.75_-{0.13}^{+0.141}\;and\;\alpha_P^c=1.99_{-019}^{+0.16}\). We find that these distributions are roughly consistent with the physical framework of a Fractal-Diffusive, Self-Organized Criticality (FD-SOC) system with the spatial dimension S = 3 and the classical diffusion β=1. Our results support that the jet responsible for the GRBs should be magnetically dominated and magnetic instabilities (e.g., kink model, or tearing-model instability) lead the GRB emission region into the SOC state.

多脉冲伽马射线暴（GRB）的可变性可能有助于从中央引擎揭示潜在过程的机制。要研究GRB的快速阶段是否存在自组织临界（SOC）现象，我们通过用马尔可夫链蒙特卡洛拟合一些观察到的物理变量的分布，统计地研究每个突发中具有3个以上脉冲的GRB的特性。包括各向同性能量E _iso，持续时间T和每个脉冲的峰值计数率P。我们的样本由CGRO / BATSE卫星观测到的93个GRB中的454个脉冲组成。这些差分频率分布的幂律指数的最佳拟合值和不确定性是：\（\ alpha_E ^ d = 1.54 \ pm0.09，\ alpha_T ^ d = 1.82 \ pm_ {0.15} ^ {+ 0.14} \;和\; \ alpha_P ^ d = 2.09 _ {-019} ^ {+ 0.18} \），而累积频率分布中的幂律指数为：\（\ alpha_E ^ c = 1.44 _ {-0.10} ^ {+ 0.08}，\ alpha_T ^ c = 1.75 _- {0.13} ^ {+ 0.141 } \;和\; \ alpha_P ^ c = 1.99 _ {-019} ^ {+ 0.16} \）。我们发现这些分布与分形扩散，自组织临界度（FD-SOC）系统的空间尺寸S = 3和经典扩散β = 1的物理框架基本一致。我们的结果支持负责GRB的射流应以磁性为主，并且磁性不稳定性（例如扭结模型或撕裂模型不稳定性）会将GRB发射区带入SOC状态。