How does an atom-smashing particle accelerator work? - Don Lincoln

让原子撞击的粒子加速器如何运作？- Don Lincoln

Transcriber: Andrea McDonough Reviewer: Bedirhan Cinar

翻译人员: Minji Seo 校对人员:

One of the grandest scientific tools ever made by mankind

在人类制造的众多伟大器械中

is called an atom smasher.

其中一样叫做'原子撞击器'

And I mean literally grand.

我说的是体积上的伟'大'

The biggest one ever built,

其中最大的

the Large Hadron Collider, or LHC,

也就是‘大型强子对撞机’或称‘LHC’

is a ring with a circumference of about 18 miles.

是一个周长约 18 英里的环形建筑

That's more than the entire length of Manhattan.

这比整个曼哈顿还长

So what is an atom smasher?

原子加速器到底是什么？

It is a device that collides atomic nuclei together

它是让具有极高能量的原子核

at extremely high energy.

互相撞击的仪器。

The most powerful one scientists have ever built

而科学家建造的能量最高的一个仪器

can heat matter to the hottest temperatures ever achieved,

可以将物质加热到有史以来的最高温度，

temperatures last seen at a trillionth of second

相当于宇宙在诞生后的

after the universe began.

兆分之一秒的温度。

Our accelerators are full of engineering superlatives.

我们的加速器由尖端工程技术构成。

The beam-containing region of the LHC is a vacuum,

LHC 的碰撞隧道是真空的

with lower pressure than what surrounds

压力比国际太空站

the international space station,

周围的气压还小，

and is 456 degrees Fahrenheit below zero,

而且温度在华氏零下 456 度 （译注：约摄氏零下 271 度），

colder than the temperature of deepest space.

比最深远的宇宙都还冷。

A previous accelerator sitting in the LHC tunnel

而先前的一个置于 LHC 加速碰撞隧道中的加速器

holds the world record for velocity,

仍保持着速度的世界纪录，

accelerating an electron to a speed so fast

它能将一个电子加速到极高的速度，

that if it were to race a photon of light,

几乎接近于光速，

it would take about 14 minutes for the photon

光子大约需要14 分钟的时间

to get a lead of about 10 feet.

才能领先 10 英尺。

If that doesn't impress you,

如果这还不让你惊讶，

remember the photon is fastest thing in the universe,

要记得光子是宇宙上最快的东西，

it goes about 186,000 miles per second.

它时速每秒大约186,000英里。

So how do these subatomic particle accelerators work?

那么，这些次原子的粒子加速器是如何运作的？（译注：次原子的是指比原子小或原子内部的）

Well, they use electric fields.

答案是利用电场。

Electric fields make charged particles move in the same way

电场让带电粒子朝相同方向运动

that gravity will pull a dropped baseball.

就像重力把棒球向下拉一样。

The force from the electric field

这样来自电场的力

will pull a particle to make it move.

将吸引粒子且使它运动。

The speed will continue to increase

速度会继续增加

until the charged particle is moving incredibly fast.

直到带电粒子到了惊人的速度。

A simple particle accelerator can be made

将两块平行金属板和一颗电池相链接起来，

by hooking two parallel metal plates to a battery.

就可制做一个简单的粒子加速器。

The charge from the battery moves

电池的电荷移动

on to the two metal plates

到两个金属板上

and makes an electric field that pulls the particle along.

产生电场来吸引粒子移动。

And that's it,

就这么简单，

you got a particle accelerator.

这就是一个粒子加速器。

The problem is that an accelerator built this way is very weak.

问题是用这种方式建造的加速器能量很小。

Building a modern accelerator like the LHC this way

如果用这种方式建设大型强子对撞机

would take over five trillion standard D-cell batteries.

则需要超过五兆个标准的一号电池。

So scientists use much stronger batteries

因此，科学家们使用更高能的电池

and put them one after another.

并将它们串联。

An earlier accelerator used this method

早期的加速器就采用了这种方法，

and was about a mile long

这种加速器大约有一英里长

and was equivalent to 30 billion batteries.

相当于300亿个电池。

However, to make an accelerator

要建造一个相当于 5 兆个

that is equivalent to five trillion batteries

电池能量的加速器

would require an accelerator 150 miles long.

则需要150英里长的加速器。

Scientists needed another way.

科学家们找到了另一种方法。

While electric fields would make a particle go faster,

电场可加速粒子，

magnetic fields make them move in a circular path.

而磁场则可使它们沿圆环路径移动。

If you put an electric field along the circle,

如果把电场沿圆环路径安置，

you don't need to use miles of electric fields,

那么就不需要数英里长的电场，

you can use a single electric field over and over again.

你可以循环使用同一电场。

The beams go around the circle,

粒子会绕着圆圈运动

and each time they gain more energy.

而每次循环电子获得更高的能量。

So very high-energy accelerators consist of

所以高能加速器包含

a short region with accelerating electric fields,

一小段的加速电场

combined with long series of magnets

和一个长系列的磁铁。

that guide the particles in a circle.

磁铁用于引导粒子沿圆环循环。

The strength of the magnets

磁场强度

and the radius of the circular path

和圆环半径

determines the maximum energy of the beam.

决定粒子束的最高能量。

Once the beam is zooming along,

一旦粒子束达到极高速度，

then the real fun begins,

真正的乐趣就开始了-

the smashing.

-对撞。

The reason physicists want to get

物理学家之所以想要

those particles moving so fast

这些粒子高速运动

is so that they can slam them into one another.

就是要让它们互相碰撞。

These collisions can teach us

这些碰撞可以帮助我们探寻

about the fundamental rules that govern matter,

物质必须遵守的基本原理，

but they'd be impossible without the feat of engineering

但如果没有工程学上的成就这是不可能的。

that is the particle accelerator.

这就是粒子加速器。