Magnetic Confinement Fusion

磁约束聚变

The development of nuclear fusion reactors presently focuses on either magnetic confinement reactors or inertial confinement processes. Even if you manage to generate the extremely high temperatures needed to initiate nuclear fusion reactions, there is no material container which can withstand such temperatures.
One solution to this dilemma is to keep the hot plasma out of contact with the walls of its container by keeping it moving in circular or helical paths by means of the magnetic force on charged particles.
解决这一困境的一种方法是通过磁力使带电粒子沿圆周或螺旋路径运动，从而将高温等离子体与容器壁保持隔离。

核融合反应堆的发展目前主要集中在磁约束反应堆或惯性约束过程上。即使你能够生成引发核融合反应所需的极高温度，也不存在任何能够承受 such 高温的材料容器。

One approach to magnetic confinement is the tokamak approach used in the Tokamak Fusion Test Reactor (TFTR) at Princeton. That project is now completed, and a large international consortium has under development the ITER to further develop magnetic confinement fusion with the goal of energy production.

磁约束的一种方法是托卡马克方法，该方法用于普林斯顿的托卡马克聚变试验反应堆（TFTR）。该项目现在已经完成，一个大型的国际联合体正在开发ITER，以进一步发展磁约束聚变，目标是实现能源生产。

Index

Fusion concepts

索引与融合概念

HyperPhysics***** Nuclear

HyperPhysics ***** 核物理

R Nave

Go Back

Tokamak Fusion Test Reactor

托卡马克熔化测试反应堆

The most well-known of the nuclear fusion test reactors is the TFTR at Princeton. It is a magnetic confinement reactor using the toroidal geometry of the tokamak, a device first developed in the USSR. It operated at Princeton from 1982 to 1997 and made many contributions to the study of nuclear fusion. It uses a combination of two magnetic fields to confine and control the plasma. One is provided by the doughnut-shaped set of external coils which provides a magnetic field along the axis of the the toroid (called the toroidal field). The other is generated by the large heating current along the toroid which heats the plasma; it is called a poloidal field. This heating current is induced by changing magnetic fields in central induction coils and exceeds a million amperes. In addition to the plasma heating by this axial current, the plasma is heated by intense beams of neutral atoms which are injected into the plasma.

最著名的核聚变实验反应堆之一是普林斯顿的TFTR。它是一种利用托卡马克装置的环形几何结构的磁约束反应堆，该装置最早在苏联开发。它于1982年至1997年在普林斯顿运行，并对核聚变研究做出了许多贡献。它使用两种磁场所结合以约束和控制等离子体。一种是由环形外部线圈提供的磁场所产生的磁场，沿着托卡马克的轴线方向（称为环形磁场）。另一种是由托卡马克内大电流产生的磁场，该电流加热等离子体；它被称为极向磁场。这个加热电流由中央感应线圈中的变化磁场感应产生，超过一百万安培。除了通过这个轴向电流加热等离子体外，等离子体还通过注入的高强度中性原子束被加热。

In December of 1993 the TFTR produced an output power level of 5.6 million watts in a controlled fusion reaction. While more power than this was required as input to the device, it represents significant progress toward "breakeven", the point at which the output power equals the input power. Progress was also reported at the Joint European Torus (JET) in England, which produced 1.7 million watts of output power in 1991. Under development is the ITER which has the goal of demonstrating the feasibility of energy production by magnetic confinement fusion.

1993年12月，TFTR实现了5.6百万瓦的输出功率，这是在受控的聚变反应中取得的。虽然设备所需的输入功率比此值更高，但这一成果标志着向“临界点”的显著进展，即输出功率等于输入功率的点。同时，英国的联合欧洲托卡马克（JET）也报告了进展，1991年其实现了1.7百万瓦的输出功率。正在开发的ITER的目标是证明通过磁约束聚变实现能源生产的可行性。

The TFTR reached a temperature of 5.1 x 10⁸ K, above the critical ignition temperature for D-T fusion, and has approached very close to the Lawson criterion, although not at the same time. The temperature reached by the TFTR was the record for highest temperature achieved. It is more than 30 times the core temperature of the Sun, which is about 1.5 x 10⁷ K.

TFTR达到5.1 x 10 8 K的温度，超过了D-T核融合的临界点燃温度，已接近洛温哈特准则，尽管并非同时达到。TFTR所达到的温度是目前最高温度的记录。它超过太阳核心温度约30倍，太阳核心温度约为1.5 x 10 7 K。