Alpha-radiation:
Alpha-radiation consists of two neutrons and two protons.That’s the Helium element. Alpha is the biggest radiation of Beta and Gamma radiation. Alpha is a very powerful radiation, that can damage your body, because it is so massive. Alpha has a speed of 15.000 km/s and that’s 5% the speed of light. But Alpha looses its energy really fast. That’s why it has a short range. Alpha can’t penetrate your skin and go through your body. And that’s why it is so dangerous. With the speed of light and that it can’t penetrate your skin, does that it has a powerful force, which will hit your skin with a massive amount of burst. If you inhale materials with a high amount of Alpha it can really damage your body.
Beta-radiation:
Beta-radiation has a longer range, and it is more penetrating. Beta emissions one electron or a positron. A positron is like an anti-electron. If a positron ever will come in contact with an electron it will be an annihilation. Because in the annihilation, 100% of the mass is converted into energy. Beta-radiation is not so dangerous as Alpha. If Beta radiation hits your body it will begin to damage it. It takes long time before you can feel/see that Beta has damaged your body, because it takes longer time for Beta to hurt your body than Alpha does. Worst of all you can get cancer. Young children especially new born children are vulnerable.The energy Beta sends out, is far more than Alpha, but less than Gamma. Like Alpha, Beta travels at the speed of light.
Gamma-radiation:
Gamma is unlike the other radiations. While the two others have an element or a mass, Gamma is just pure energy. Electromagnetic energy (EM). It takes a paper to stop Alpha. it takes an iron plate to stop Beta. But with Gamma it takes more than that. It takes a block of lead. Because as you know Alpha has a high mass, because it consists of the Helium element. That’s why it only takes a paper to stop it. Beta has a small particle. It’s not near as big as Alpha because it needs an iron plate to stop it. Because Beta sends out an electron or a positron. An electron is 2000 times smaller than a proton. Remember a proton and a positron is not the same! Gamma is energy, and that’s why it takes more than an iron plate to stop it. So why can lead stop it? As it is, Gamma belongs in the EM wave class. That means that EM waves get absorbed during the penetration of the lead. What absorbs the energy? It’s the electrons. They absorb the energy and converts it into heat or light. Because Gamma can generate heat with the help of the electrons from the lead, it can maybe in the future be used in many products. But the main source of this, will be to use it to make electricity. You could also combine positrons and a electrons in a controlled environment. That will force them together and make an explosion and form energy, used to make electricity.
Alpha-radiation is not very penetrating, so that means that a little simple paper can stop the radiation. There need to be 8 pieces of paper to stop Alpha-radiation.
Beta-radiation is a little bit more penetrating than Alpha, so Beta can’t be stop by paper. Aluminium can stop Beta-radiation. There need to be 8 pieces of paper and round about 2 mm aluminium.
Gamma-radiation is very penetrating, so it is hard to stop the energy. There need to be 7 cm lead before Gamma is slowed down.
Everyone on the earth, is exposed to radiation every hour. But it isn’t dangerous. Our organism is build for that, so it can’t hurt us. We can’t do anything to stop the daily radiation. This is called background radiation.
What do we use Alpha-radiation for?
Alpha is used in fire alarms or smoke detectors because in the fire alarm there is some Americium-241. There is like 1/5000 of a gram in it, but Americium sends out Alpha radiation. Americium constantly releases Alpha which knocks the electrons of the air. It ionizes the oxygen and nitrogen which are in the chamber. The positive oxygen and nitrogen are attached to the negative plate while the electrons are attached to the positive plate. That generates a small electric current. When smoke enters the chamber, the smoke particles attach to the ions and neutralise them. The effect of that is, that the ions don’t reach the plate. It stops the electric current and triggers the fire alarm.The Alpha particle is also in the atomic bomb. Uranium-235 sends out Alpha particle. The Alpha particle hits the other Uranium atoms and a nuclear fission is about to be created instantly. When a fission happens it generates a lot of heat, and then the big iron barrel can’t hold the pressure anymore.
What do we use Beta-radiation for?
We use Beta-radiation to cure people of cancer. When people get cancer in their cells, they go to a hospital. At the hospital they get radiotherapy. A machine, shoot radiation beams, at the place where you have got cancer. The radiation beams destroy the cells in which you have got cancer, and that will help you out of cancer. There are some side effects. When the machine shoot radiation beams at the place in which you have got cancer, you also loose the good cells. The worst that can happen is that you can loose your hair or you can get sterile. You can only be sterile if you get radiation beams in your testicles.
What do we use Gamma-radiation for?
Often when a fusion happens it creates energy in form of Gamma radiation. Gamma rays are the most energetic form of light and are produced in the very hot area of the universe. They are also produced in a supernova explosion. A supernova is a way to describe how massive stars die, like you have heard before, our sun is a star, not a planet. When the sun gets older and older, it grows to a massive size. By the end, the size of the sun will fill the whole solar-system and completely destroy all the planets. When the sun is at it’s biggest, it explodes. Not just a normal tiny explosion, but an explosion that is so powerful that it could erase the Milkyway. That is a supernova. Gamma rays are used in astronomy. Every star, supernova, black hole, solar flares and active galaxies send out gamma rays. When we invented the telescope which could see gamma rays, everything became much more clear. We could now experience a whole new level of exploring the galaxies.
Nuclear Phychics
Nuclear phychics were discovered in 1896 by a man called Henri Becquerel. In a coincidence he discovered that uranium salt blackened his photographic plates. He let the uranium salt be in his window for about 3 hours. The uranium salt was put on top of photographic plates. The uranium salt was wrapped in photographic film, so the sunshine couldn’t shine at the uranium salt. That is how he discovered it. In 1903 he got the Nobelprice for that discovery. Later they discovered that the reason of the blackened photographic plates was the changes in the unstable nuclear core.
This is also about radiation. If something emits Alpha radiation, it gives out 2 protons and 2 neutrons. Alpha is the largest radiation beam which exists. So it will go from one element to another.This is the solution:241Am237Np+4He. If you got 241Am and it releases alpha radiation, then that means 4helium molecule, travel away from it. Then it gets 4 less nucleons and then it becomes another element 237Np. But of course it takes time before an element becomes another element. That is what we call half-life. Half life is the time it takes to become another element. When a half life is gone 50% of it is covered into another element, now in this reason it’s Neptunium. When another half life is gone, 50% percentages of the rest of the Americium is covered into Neptunium. So now there’s only 25% left. This will happen until all of it, is covered into Neptunium. One half life of Americium is 432 years.
This doesn't happen in Beta radiation. In Beta radiation something else happen. Beta radiation sends out one proton and one electron. This happens when a neutron is transmuted into a proton and an electron. When a core gets another proton it becomes another element.
So Strontium sends out an electron and a proton. That will then say that the next element will get another proton. In this case it’s another Strontium molecule. When that happens it get another proton and therefore it will change into another element. The half life of Strontium is right around 29 years.
Gamma radiation is a electromagnetic beam. It is pure energy, and when an element emits gamma, none element transfusion happens. It doesn’t change into another element, it stays the same. Gamma radiation is in the same league as X-rays and Radio waves.
By Emil and Mikkel (9.A)
No comments:
Post a Comment