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

讓原子撞擊的粒子加速器如何運作？ - Don Lincoln

Transcriber: Andrea McDonough Reviewer: Bedirhan Cinar

譯者: Jephian Lin 審譯者: 盧 曉天

One of the grandest scientific tools ever made by mankind

在人類製造的眾多偉大器械中

is called an atom smasher.

其中一樣叫做 原子撞擊器

And I mean literally grand.

我說的是實際上的偉「大」

The biggest one ever built,

其中最大的

the Large Hadron Collider, or LHC,

也就是「大型強子撞擊機」 或稱 LHC

is a ring with a circumference of about 18 miles.

是一個周長約 18 英里的環形建築

That's more than the entire length of Manhattan.

它比曼哈頓的全長還長

So what is an atom smasher?

所以 什麼是原子撞擊器？

It is a device that collides atomic nuclei together

它是一個用極高能量 讓原子核

at extremely high energy.

互相撞擊的儀器

The most powerful one scientists have ever built

而科學家曾建過 最具能量的一個

can heat matter to the hottest temperatures ever achieved,

可以將物質加熱到 前所未有的溫度

temperatures last seen at a trillionth of second

這溫度最後一次出現是在 宇宙誕生後的

after the universe began.

兆分之一秒

Our accelerators are full of engineering superlatives.

我們的加速器有著 許多工程上的「最」

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

LHC 的加速區是真空的

with lower pressure than what surrounds

壓力比國際太空站 周圍的氣壓還小

the international space station,

壓力比國際太空站 周圍的氣壓還小

and is 456 degrees Fahrenheit below zero,

而且是華氏零下 456 度 （譯註：約攝氏零下 271 度）

colder than the temperature of deepest space.

比最深遠的宇宙都還冷

A previous accelerator sitting in the LHC tunnel

而在 LHC 通道中的 前一個加速器

holds the world record for velocity,

創下了速度的世界紀錄

accelerating an electron to a speed so fast

將一個電子加速到極高速

that if it were to race a photon of light,

使得如果它和 光子賽跑

it would take about 14 minutes for the photon

光子須要花 14 分鐘才能

to get a lead of about 10 feet.

領先 10 英尺

If that doesn't impress you,

如果這沒有讓你印象深刻

remember the photon is fastest thing in the universe,

記住光子是宇宙中最快的粒子

it goes about 186,000 miles per second.

它每秒可以走 186,000 英里

So how do these subatomic particle accelerators work?

所以這些次原子的粒子加速器是如何運作的？ （譯註：次原子的是指比原子小或原子內部的）

Well, they use electric fields.

答案是利用電場

Electric fields make charged particles move in the same way

電場讓帶電粒子朝同方向運動

that gravity will pull a dropped baseball.

就像重力把棒球向下拉一樣

The force from the electric field

這樣來自電場的力

will pull a particle to make it move.

會將吸引粒子並使它運動

The speed will continue to increase

速度會持續增加

until the charged particle is moving incredibly fast.

直到帶電粒子到了 不能置信的速度

A simple particle accelerator can be made

簡單的粒子加速器可以用

by hooking two parallel metal plates to a battery.

兩塊金屬板和一顆電池相連結 來製做

The charge from the battery moves

電池的電荷會傳到

on to the two metal plates

兩塊金屬板上

and makes an electric field that pulls the particle along.

然後產生電場來 吸引粒子移動

And that's it,

就這樣

you got a particle accelerator.

你完成一個粒子加速器

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

問題是這樣的加速器 效能是不強的

Building a modern accelerator like the LHC this way

用這種方試來建造 LHC

would take over five trillion standard D-cell batteries.

要花上 5 兆個 標準型一號電池

So scientists use much stronger batteries

所以科學家們使用了更強的電池

and put them one after another.

而且一個一個連接下去

An earlier accelerator used this method

一個較早的加速器 就使用這個方法

and was about a mile long

並接了一英里長

and was equivalent to 30 billion batteries.

相當於用了 300 億顆電池

However, to make an accelerator

然而，要做一個效能

that is equivalent to five trillion batteries

與 5 兆顆電池相當的加速器

would require an accelerator 150 miles long.

則須要 150 英里長

Scientists needed another way.

科學家必須另覓出路

While electric fields would make a particle go faster,

當電場在加速粒子的同時

magnetic fields make them move in a circular path.

磁場也引導它們 繞行在圓形的軌道上

If you put an electric field along the circle,

如果把電場設置成環形

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

你就不須要用到 好幾英里長的電場

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

而可以重覆使用同一個電場許多次

The beams go around the circle,

而粒子會繞著圓圈運動

and each time they gain more energy.

每次都更具能量

So very high-energy accelerators consist of

所以好的高能加速器 只包含了

a short region with accelerating electric fields,

一小段加速電場

combined with long series of magnets

以及一連串 引導粒子轉彎的磁鐵

that guide the particles in a circle.

以及一連串 引導粒子轉彎的磁鐵

The strength of the magnets

這些磁鐵的強度

and the radius of the circular path

以及圓形軌道的半徑

determines the maximum energy of the beam.

決定了粒子的最高能量

Once the beam is zooming along,

如果粒子開始高速移動

then the real fun begins,

有趣的事發生了──

the smashing.

碰撞

The reason physicists want to get

物理學家想要讓粒子 如此高速移動的原因

those particles moving so fast

物理學家想要讓粒子 如此高速移動的原因

is so that they can slam them into one another.

是因為他們可以讓粒子互相碰撞

These collisions can teach us

這些碰撞可以教導我們

about the fundamental rules that govern matter,

一些物質必須遵守的 基本原理

but they'd be impossible without the feat of engineering

但如果沒有工程學上的豐功偉業， 也就是粒子加速器

that is the particle accelerator.

這些碰撞是不可能發生的