
English: 
When people hear the words nuclear reactor,
They usually think of big, expensive, and dangerous machines that create radioactive waste.
What if I told you that nuclear fission reactors, the type currently in use, have a cleaner, safer, and more efficient brother?
Before we talk about reactors, let's talk about reactions. There are two types of nuclear reactions:
The first is fission, where a large nucleus is made to split into smaller nuclei.
The second is fusion, where smaller nuclei combine to form a larger one.
Fusion has numerous advantages over fission. For one, fusion doesn't require specialized isotopes of uranium as fuel;
instead it uses simple hydrogen.
In fact, one liter of water contains enough hydrogen such that, if they all fuse into helium,
The energy released will be the same as the combustion of 300 liters of gasoline, making fusion at least four times more efficient than fission.
But just how do we constructed a fusion reactor?
Well, in order for nuclear fusion to occur, the particles in the fuel, typically hydrogen nuclei,
Must be moving fast enough to overcome the positive positive repulsion between each other. In other words,

Chinese: 
当人们听到“核能反应堆，"
人们通常会联想到那些又大又贵又有泄露有放射性物质的危险的机器。
但是，你知不知道，现在应用的核裂变反应堆有一种更加干净，安全，和高效率的兄弟？
讲反应堆之前，让我们先讨论讨论各种反应。高中时我们学到原子核能有两种反应。
第一种是核裂变。核裂变发生时，一个较大的原子核被迫分裂成几个小的原子核。
第二种是核聚变。核聚变发生时，几个较小的原子核合成一个更大的原子核。
相对来说，核聚变比核裂变有很多优点。首先，核聚变不需要铀的同位素。
用简单的氢原子就好。
事实上，如果一升水里面的氢全部聚变成氦，
这个反应中释放出的能量相当有300升汽油。这表明了聚变比裂变的效率高至少四倍！
但是，我们到底怎样才能制造核聚变反应堆呢？
如果我们想核聚变在地球表面上发生，核聚变用的原料（一般都是氢原子核）
要移动非常快，才能抵消两个正原子核的同极的排斥效应。换句话来说，

English: 
They feel must be hot. So hot the field becomes plasma.
However, because the plasma is usually very thin, if it touches any matter, it will rapidly cool, ceasing all fusion reactions.
Thus, we must contain a plasma not with physical walls, but magnetic ones.
Charged particles, like those in a plasma, are affected by magnetic fields. If we create a coil of wires, called a solenoid,
magnetize it, and place the charged particle inside it, the particle will move around in a circle, like this. If
the magnetic field is tuned properly, the particle will be forever confined within a fixed radius.
However, with this configuration the particle is free to move out the sides. To prevent this, we curl the solenoid into a circle.
However, this creates some problems. Notice that there are more coils per area on the inside of the reactor than the outside. Since the strength
of magnetic field of a solenoid is dependent on a number of calls per area,
there will be a stronger magnetic field on the inside of the torus.

Chinese: 
核聚变的原料一定要非常热。热到软料成为等离子为止。
但是，应为我们的等离子非常的薄，如果这个等离子碰到任何物质，等离子的温度会飞快下降。这样一来，全部核聚变反应都会停止。
尽然我们不能用我只来容纳氢原子的等离子，那么我们只能用磁铁啦~
等离子里面的粒子是带电的，所以这些粒子会受磁场的影响。如果我们制造一个电磁圈，
给这个电磁圈通电，然后把我们的氢原子核置入电磁圈之内，氢原子核会以这样子的路线运动。
如果我们的磁场有被设置准，我们的粒子会永远在这个圈内进行运动。
尽管如此，如果我们只用一个电磁圈的话，我们的粒子可以很容易地走出我们的电磁圈。为了防止这个，我们把电磁圈变成一个圆形。
这制造了更多问题。注意：花托的内部磁圈的密度比花托外部的多的多。因为磁场的强度
取决于磁圈的密度，
花托内部的磁场会比花托外部的磁场强。

English: 
This difference in magnetic field density causes the plasma to gather at the top and bottom walls of the reactor--
not good,
if the point of the field is to get the plasma as far away from matter as possible.
To fix, this we make the coil into a D-shape, which makes the field denser on the outer edges, effectively canceling out the uneven infield.
in theory,
This should all worked perfectly to produce and contain stable plasma, thus enabling fusion. Part of the energy released from fusion
can then be used to heat the plasma, beginning a chain reaction that only needs new fuel to continue.
In reality, containing the plasma for long is extremely difficult.
So difficult, the world record for longest fusion pulse is only six and a half minutes!
Operating in fusion reactors is extremely hard demanding as well.
Say our fictional fusion reactor generate 16 megawatts of power. Subtract
The power needed to run the electromagnets, cool the magnets to superconducting temperatures,
heat the plasma, and that number quickly spirals into the negatives! So can fusion reactors work?
Theoretically, yes, but it will take us a lot of work to get there.

Chinese: 
磁场密度的不同造成了一个特别的效应：等离子会在反应堆的上下区域聚集。
这样不好，
应为我们之所以运用了磁场是因为我们不想让等离子跟任何物质碰撞。
其实导正这个问题还算简单：我们只要把电磁从O型变到D型。这样一来，只要磁圈外围的磁场会相对应来说更加强，整个花托的磁场会基本上全部稳定。
理论上来说，
用这个系统来制作稳定的等离子是轻而易举的。只要我们有在聚变中的等离子，我们能用聚变的一部分的能量来
从新加热等离子，从而引发一个只需新氢原子核的连锁反应。
现实比理论差得远。想要长时间容纳稳定的等离子？
想的美，人家世界纪录才容纳个六分半钟呢。
想要一个核聚变反应堆应作，我们也需要很多很多的能量。
打个比方：如果一个虚幻的核聚变反应堆释放1.6千万的能量。减去
发动电磁圈的能量，把电磁圈变成超导体的能量，
加热等离子要用的能量，我们的反应堆反而在耗很多很多的能量！所以我们到底能不能见到有效核聚变反应堆的那天？
既要我们肯努力，啥事都有可能。
