Turbulent transport in the inner core of the high-β JET hybrid discharge 75225 is investigated extensively through linear and non-linear gyro-kinetic (GK) simulations using the GK code GKW in the local approximation limit. Compared to previous studies (Citrin etal 2015 Plasma Phys. Control. Fusion 57 014032; Garcia etal 2015 Nucl. Fusion 55 053007), the analysis has been extended towards the magnetic axis, ρ < 0.3, where the turbulence characteristics remain an open question. Understanding turbulent transport in this region is crucial to predict core profile peaking that in turn will impact the fusion reactions and the tungsten neoclassical transport, in present devices as well as in ITER. At ρ = 0.15, a linear stability analysis indicates that kinetic ballooning modes (KBMs) dominate, with an extended mode structure in ballooning space due to the low magnetic shear. The sensitivity of KBM stability to main plasma parameters is investigated. In the non-linear regime, the turbulence induced by these KBMs drives a significant ion and electron heat flux. Standard quasi-linear (QL) models are compared to the non-linear results. The standard reduced QL models work well for the E B fluxes, but fail to capture magnetic flutter contribution to the electron heat flux induced by the non-linear excitation of low k _θ ρ _i micro-tearing modes that are linearly stable. An extension of the QL models is proposed allowing better capturing the magnetic flutter flux.

在高的内芯湍流输运β JET混合放电75225是通过利用在局部近似极限GK代码GKW线性和非线性陀螺动力学（GK）模拟广泛的研究。相比以前的研究（西特林等人2015年等离子物理学控制融合。 57 014032;加西亚等人2015年。NUCL融合 55 053007）时，分析已被扩展向磁轴，ρ<0.3，湍流特性仍然是一个悬而未决的问题。了解该区域的湍流输运对于预测岩心峰达到峰值至关重要，而岩心廓线达到峰值将依次影响聚变反应和钨在新装置中以及在ITER中的新古典运移。在ρ = 0.15处，线性稳定性分析表明，动态膨胀模式（KBMs）占主导地位，由于低磁剪切力，在膨胀空间中具有扩展模式结构。研究了KBM稳定性对主要血浆参数的敏感性。在非线性状态下，这些KBM引起的湍流会驱动很大的离子和电子热通量。将标准准线性（QL）模型与非线性结果进行比较。标准的简化QL模型适用于E B通量，但无法捕获到电子热磁扑贡献通量低的非线性激发诱导ķ _θ ρ_我微撕裂是线性稳定模式。提出了QL模型的扩展，可以更好地捕获磁扑通量。