Conditions for Fusion核融合的条件
In addition to providing a sufficiently high temperature to enable the particles to overcome the Coulomb barrier, that temperature must be maintained for a sufficient confinement time and with a sufficient ion density in order to obtain a net yield of energy from a fusion reaction. The overall conditions which must be met for a yield of more energy than is required for the heating of the plasma are usually stated in terms of the product of ion density and confinement time, a condition called Lawson's criterion. 除了提供足够高的温度以使粒子能够克服库仑屏障外，该温度还必须维持足够长的约束时间，并且具有足够的离子密度，以便从聚变反应中获得净能量。要实现比加热等离子体所需能量更多的能量输出，通常用离子密度和约束时间的乘积来表示这些条件，这一条件被称为劳伦兹准则。
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Confinement Time for Fusion核融合的约束时间
Confinement time in nuclear fusion devices is defined as the time the plasma is maintained at a temperature above the critical ignition temperature. To yield more energy from the fusion than has been invested to heat the plasma, the plasma must be held up to this temperature for some minimum length of time. Calculations of that minimum time are 在核聚变装置中，约束时间被定义为等离子体维持在高于临界点燃温度的时间。为了从聚变中获得比加热等离子体所投入的能量更多的能量，等离子体必须被维持在这一温度上至少一段时间。计算该最小时间的成果是
where n is the ion density in the plasma. The product of the ion density and confinement time required for fusion is called Lawson's criterion. 其中，n 是等离子体中的离子密度。离子密度与实现融合所需的约束时间的乘积称为劳伦茨准则。
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Ion Density for Fusion聚变离子密度
Even given a high enough temperature to overcome the coulomb barrier to nuclear fusion, a critical density of ions must be maintained to make the probability of collison high enough to achieve a net yield of energy from the reaction. The density required for a net energy yield is correlated with the confinement time for the hot plasma, so the minimum condition for a productive fusion reaction is typically stated in terms of the product of the ion density and confinement time, called Lawson's criterion. The calculated values are 即使有足够高的温度以克服核融合的库仑势垒，也必须维持足够的离子密度，以使碰撞概率足够高，从而实现反应的净能量收益。实现净能量收益所需的密度与等离子体的约束时间相关，因此，产融融合反应的最低条件通常以离子密度和约束时间的乘积来表示，称为劳伦兹准则。计算得到的值为
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Lawson's Criterion for Fusion核融合的劳森准则
Once a critical ignition temperature for nuclear fusion has been achieved, it must be maintained at that temperature for a long enough confinement time at a high enough ion density to obtain a net yield of energy. In 1957, J. D. Lawson showed that the product of ion density and confinement time determined the minimum conditions for productive fusion, and that product is commonly called Lawson's criterion. Commonly quoted figures for this criterion are 一旦实现了核融合的临界点燃温度，就必须维持该温度足够长的约束时间，并在足够高的离子密度下，以获得净能量输出。1957年，J. D. Lawson证明了离子密度和约束时间的乘积决定了产生融合所需的最小条件，并且这个乘积通常被称为Lawson准则。通常引用的这一准则数值为
The closest approach to Lawson's criterion has been at the Tokamak Fusion Test Reactor (TFTR) at Princeton. It has reached ignition temperature and gotten very close to Lawson's criterion, although not at the same time. 托卡马克核聚变试验反应堆（TFTR）在普林斯顿达到了接近劳森准则的水平。它已经达到了点火温度，并非常接近劳森准则，尽管并非同时实现。
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