Gamma 衰变

This stunning image is an artist’s rendition of a burst. A gamma ray burst is a sudden, intense flash of gamma rays given off by an extremely energetic explosion. The bursts have been observed in distant galaxies. But gamma rays also occur on Earth.
::这一惊人的图像是艺术家对爆破的解说。 伽马射线暴是一场极强的爆炸所释放的伽马射线的突然、强烈闪烁。 喷射是在遥远的星系中观测到的。 但伽马射线也在地球上发生。

What Are Gamma Rays?
::什么是伽马射线?

Gamma rays are . Electromagnetic waves are waves of electric and magnetic that travel through space at the speed of light . The energy travels in tiny “packets” of energy, called photons . Photons of gamma energy are called gamma particles. Other electromagnetic waves include , light rays, and X rays. Gamma rays have the greatest amount of energy of all electromagnetic waves. 
::伽马射线是。电磁波是电磁波,以光速穿越空间。能量在微小的能量“容器”中流动,称为光子。伽马能量的光子称为伽马粒子。其他电磁波包括光线和X射线。伽马射线是所有电磁波中最大能量的。

Gamma Rays and Radioactive Decay
::伽马射线和放射性衰变

Gamma rays are produced when radioactive decay. Radioactive elements are elements with unstable nuclei . To become more stable, the nuclei undergo . In this process, the nuclei give off energy and may also emit charged particles of matter. include alpha, beta, and gamma decay. In alpha and , both particles and energy are emitted. In gamma decay , only energy, in the form of gamma rays, is emitted.
::放射性衰减时会产生伽玛射线。放射性元素是不稳定核元素。要更加稳定,核将经历。在这一过程中,核释放能量,并可能释放有电物质粒子。包括α、β和伽马衰变。在α和(和)粒子和能量中,排放。在伽马衰变中,只有伽马射线形式的能量被释放。

Alpha and beta decay occur when a nucleus has too many or an unstable ratio of protons to . When the nucleus emits a particle, it gains or loses one or two protons, so the becomes a different element. Gamma decay, in contrast, occurs when a nucleus is in an excited state and has too much energy to be stable. This often happens after alpha or beta decay has occurred. Because only energy is emitted during gamma decay, the number of protons remains the same. Therefore, an atom does not become a different element during this type of decay.
::当核体的质子与质子之比过多或不稳定时,就会发生阿尔法和贝塔的衰变。当核核释放粒子时,就会增减一两个质子,从而形成一个不同的元素。相反,当核体处于兴奋状态,能量过多而不能稳定时,会发生伽玛的衰变。由于在伽玛衰变期间仅释放能量,质子的数量保持不变。因此,原子在这种衰变期间不会成为不同的元素。

Q: The Figure shows how helium-3 (He-3) decays by emitting a gamma particle. How can you tell that the atom is still the same element after gamma decay occurs?
::Q: 图表显示了-3 (He-3) 是如何通过排放伽马粒子而衰减的。 您如何判断在伽马衰变发生后原子仍然是相同的元素 ?

A: The has two protons (red) before the reaction occurs. After the nucleus emits the gamma particle, it still has two protons, so the atom is still the same element.
::A: 在反应发生前有两个质子( 红色) 。 在核释放伽马粒子后, 它仍然有两个质子, 所以原子仍然是相同的元素 。

Dangers of Gamma Radiation
::伽玛辐射危险

Gamma rays are the most dangerous type of radiation. They can travel farther and penetrate materials more deeply than can the charged particles emitted during alpha and beta decay. Gamma rays can be stopped only by several centimeters of lead or several meters of concrete. It’s no surprise that they can penetrate and damage cells deep inside the body. 
::伽马射线是最危险的辐射类型。 伽马射线可以比在α和β衰变期间释放的充电粒子更深入和穿透材料。 伽马射线只能用几厘米的铅或几米的混凝土来阻止。 它们能够穿透和破坏体内深处的细胞并不奇怪。

Summary
::摘要

播放段落
• Gamma rays are electromagnetic waves that carry photons of energy called gamma particles. They are the most energetic of all electromagnetic waves.
  ::伽马射线是电磁波,含有光子能量,称为伽马粒子,是所有电磁波中最能发力的。
播放段落
• Gamma rays are produced during gamma decay of an excited nucleus. During gamma decay, the nucleus emits a “packet” of energy called a gamma particle.
  ::伽马射线在刺激核的伽马衰变期间产生。在伽马衰变期间,伽马射线释放出一种叫做伽马粒子的“能量包 ” 。 在伽马核衰变期间,伽马射线会释放出一种叫做伽马粒子的“能量包 ” 。
播放段落
• Gamma rays are more dangerous than the particles of matter emitted during alpha or beta decay.
  ::伽玛射线比在α或β衰变期间释放的物质粒子更危险。

Review
::回顾

播放段落
1. What are gamma rays?
   ::什么是伽马射线?
播放段落
2. What happens during gamma decay?
   ::伽马衰变期间会发生什么?
播放段落
3. Explain why gamma decay occurs.
   ::解释为什么伽马衰变会发生

Resources
::资源