Why is alpha radiation used in smoke detectors rather than beta or gamma radiation?

Why is alpha radiation used in smoke detectors rather than beta or gamma radiation?

An isotope of americium which emits alpha particles is used in smoke alarms. Alpha radiation ionises the air and this allows a small current to flow between two electrodes. Alpha is weakly penetrating so smoke stops it, the current drops and the alarm goes off.

Why is alpha particles used in smoke detectors?

Alpha particles from the americium source ionize air molecules. This makes some particles positively charged and some negatively charged. Two charged plates inside of the ionization smoke detector create a flow of positively and negatively charged ions.

Why are radioisotopes used in smoke detectors?

One of the most common uses of radioisotopes today is in household smoke detectors. These ‘ionisation chamber’ smoke detectors are the most popular because they are inexpensive and are more sensitive to flaming fire conditions with little smoke than the other type. They contain americium.

Is alpha beta or gamma charged?

Alpha particles carry a positive charge, beta particles carry a negative charge, and gamma rays are neutral. An alpha particle is made up of two protons and two neutrons bound together. Beta particles are high energy electrons.

How much radiation do people with two smoke detectors in their houses receive per year?

Smoke detectors are very safe Most units sold today use one microcurie or less of americium-241. A 2001 NRC study found people with two of these units in their homes receive less than 0.002 millirems of radiation dose each year.

Why is curium 242 not suitable for use inside smoke detectors?

(i) The smoke detector would not work if a radioactive source that emitted only gamma rays was used. (ii) Curium-242 is a radioactive isotope with a half-life of 160 days. It emits alpha particles.

Are carbon monoxide detectors radioactive?

It is important to note that carbon monoxide detectors do not contain radioactive material and can be disposed of as you would photoelectric smoke detectors. Some manufacturers also have take-back programs as well.

Are fire alarms radioactive?

Ionization chamber smoke detectors contain a small amount of americium-241, a radioactive material. They react quickly to fires that give off little smoke. Ionization smoke detectors expose people to a tiny amount of radiation—about 1/100 of a millirem per year.

What are the possible dangers to cells from radiation?

Ionizing radiation can affect the atoms in living things, so it poses a health risk by damaging tissue and DNA in genes. has sufficient energy to affect the atoms in living cells and thereby damage their genetic material (DNA). Fortunately, the cells in our bodies are extremely efficient at repairing this damage.

Why does a smoke detector use alpha radiation rather than beta radiation?

– Answers Why does a smoke detector use alpha radiation rather than beta or gamma radiation? Because you want type of low energy radiation that can be stopped by a very thin sheet of metal. or , indeed, paper. Beta would go through your skin and gamma, your house.

Why is an alpha emitter used in smoke?

The main reason that alpha particles are used is that they are strongly ionizing, because they are helium nuclei without any orbiting electrons; they will rip electrons off of any particles that they encounter, whereas gamma rays and beta particles will not.

What kind of particles are used in smoke detectors?

Alpha particles in smoke detectors. Radioactive isotopes which emit alpha particles can be used in smoke detectors. The animation below shows a smoke detector with the radioisotope Americium 241 as the alpha source.

What makes an ionization chamber smoke detector work?

Ionization chamber smoke detectors contain a small amount of americium-241, a radioactive material. Smoke particles disrupt the low, steady electrical current produced by radioactive particles and trigger the detector’s alarm. They react quickly to fires that give off little smoke.