STATEMENT OF THE PROBLEM
How can the ionization chamber detect if the environment is surrounded or has Radon? Sub- Problems:
What are the primary sources of radon gas?
What elements are found when radon decays?
How can this gas cause different kinds of diseases?
Build a simple ionization chamber that is capable of detecting fairly low levels of radiation
BACKGROUND OF THE STUDY
Radon is a cancer-causing gas. It comes from the natural breakdown of uranium in soil, rock and water and gets into the air you breathe. These radioactive materials "decay" into lighter elements, emitting energetic sub-atomic particles in the process, and one of those lighter elements is Radon. Since radon is a noble gas, it is chemically inert and doesn't stay bound in the solid the way it's parent did. It diffuses right through solids and ends up floating freely in the air. Being a noble gas, radon is fairly harmless, itself. You breathe in some radon with every breath but then you breathe it right back out, since it isn't chemically active or electrically charged. But radon has a short half-life of only about four days, meaning that about half of it will decay within four days, producing new, even lighter radioactive isotopes of other elements like polonium, lead, and bismuth. Those isotopes keep decaying, until a stable isotope of lead is reached. These radon "daughters" are not noble gasses like radon, they are usually ionized when they are produced, and they will readily stick to anything nearby, like healthy lung tissue. They typically have an even shorter half-life than radon and quickly decay inside the lung, kicking out energetic alpha and beta particles that can cause tissue damage and potentially trigger lung cancer. This unfortunate chain of events is due to the decay chain including a noble gas. Radon gas is considered to be the second leading cause of lung cancer. It can get into any type of building — homes, offices, and schools — and result in a high indoor radon level. But, we are most likely to get your greatest exposure at home, where we spend most of our time. It typically moves up through the ground to the air above and into your home through cracks and other holes in the foundation. Any home traps radon inside, where it can build up. Any home may have a radon problem. This means new and old homes, well-sealed and drafty homes, and homes with or without basements. These are examples where you can find the noble gas:
1. Cracks in solid floors
2. Construction Joints
3. Cracks in walls
4. Gaps in suspended floors
5. Water supply
It breaks down into solid radioactive elements called radon progeny. Radon progeny can attach to dust and other particles and can be breathed into the lungs. As radon and radon progeny in the air break down, they give off alpha particles, a form of high-energy radiation that can damage our health. Radon daughters will stick to just about anything they encounter, so they are easily collected by drawing air through a dusting cloth with an ordinary fan. After collecting the daughters for about an hour or two, the radiation being emitted from the cloth due to the further decay of the collected radioactive isotopes can be measured with a simple ionization chamber made from an empty coffee can, a single Darlington transistor, and a digital voltmeter. The deceivingly simple ion chamber is quite sensitive and can detect radon daughters in buildings with radon concentrations below the "action level" recommended by health authorities. A simple ionization chamber is nothing more than a metal can with a wire inside. When a radioactive particle passes through the air in the chamber, many of the molecules of air are ionized, having electrons knocked loose from the outer atomic shells. Applying a positive voltage on the outer can relative to the internal wire, causes these ions to be attracted to the wire and the free electrons to be attracted to the interior wall...
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