Experimental asymmetries in fusion implosions can lead to magnetic field generation in the hot plasma core. For typical parameters, previous studies found that the magnetization Hall parameter, given by the product of the electron gyro-frequency and Coulomb collision time, can exceed one. This will affect the hydrodynamics through inhibition and deflection of the electron heat flux. The magnetic field source is the collisionless Biermann term, which arises from the Debye shielding potential in electron pressure gradients. We show that there is an additional source term due to the Z dependence of the Coulomb collision operator. If there are ion composition gradients, such as jets of carbon ablator mix entering the hot-spot, this source term can rapidly exceed the Biermann fields. In addition, the Biermann fields are enhanced due to the increased temperature gradients from carbon radiative cooling. With even stronger self-generated fields, heat loss to the carbon regions will be reduced, potentially reducing the negative effect of carbon mix. This article is part of a discussion meeting issue ‘Prospects for high gain inertial fusion energy (part 1)’.

中文翻译：

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惯性约束聚变燃料中成分梯度产生的磁场

聚变内爆的实验不对称性会导致热等离子体核心产生磁场。对于典型参数，之前的研究发现，由电子陀螺频率和库仑碰撞时间的乘积给出的磁化霍尔参数可以超过 1。这将通过电子热通量的抑制和偏转来影响流体动力学。磁场源是无碰撞比尔曼项，它由电子压力梯度中的德拜屏蔽势产生。我们表明，由于库仑碰撞算子的 Z 依赖性，还有一个额外的源项。如果存在离子成分梯度，例如进入热点的碳烧蚀剂混合物射流，则该源项会迅速超过 Biermann 场。此外，由于碳辐射冷却引起的温度梯度增加，Biermann 场增强。有了更强大的自生场，碳区域的热量损失将减少，从而可能减少碳混合的负面影响。本文是讨论会议问题“高增益惯性聚变能的前景（第 1 部分）”的一部分。