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Alpha is used because it rarely effects our bodies from the outside. This is because it only travels approximately 5cm.
Beta and Gamma are more dangerous as they can travel through your skin.
Wiki User
∙ 15y ago
Wiki User
∙ 11y agobecause it has the least penetrating power so it is more sensitive to smoke in the air, compared to beta radiation which would require nearly impossible amounts of smoke to block the radiation to the sensor.
Wiki User
∙ 12y agoThe smoke alarm is an ion chamber, like a GM tube, and it has a high voltage potential across two electrodes. The alpha particles that are emitted from a small amount of americium-241 interact with the ion chamber and cause a measurable current to flow between the electrodes. When smoke is present, it also interacts with the alpha particles, reducing the current flow across the electrodes, setting off the alarm.
Wiki User
∙ 11y agoIonization type smoke detectors use a tiny bit of radioactive material to ionize (electrically charge) the air in a compartment. When smoke enters the compartment, it changes the rate that the electrical charge bleeds off in the air. This is detected by the electronic circuitry, and trips the alarm.
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What use is alpha radiation?
It is used in smoke detectors as it cannot travel far in air. Alpha radiation is emitted and as long as the detector in the device is receiving the alpha radiation, then no smoke is present. When smoke particles are present, they interrupt the radiation, and so the detector doesn't pick up the radiation, causing the alarm to go off.
Why do you use alpha radiation?
we use alpha radiation to know whether smoke has been let off in the school at home so if it has we can run out without being inflicted with pain
What kind of particles does the emitter create in a smoke alarm?
Smoke alarms typically use photo-electric sensors or alpha-particle emitters, although the photo-electric sensors are much better for detecting smoldering fires.
Are smoke alarms radioactive?
Most smoke alarms use Americium-241 to detect smoke and hot air, thus triggering the alarm. Some gamma radiation is emitted by the smoke alarm but all the alpha radiation is blocked by the black box. Living for a year within 1 metre of a smoke alarm would give you a radiation dose of 1.5 millimeters per year, which is about 1/1000th of the radiation that we receive normally. If you held a smoke alarm in your hand then you would get a significant dose, but you're not going to do that are you? The Americium is chosen because of it's very high melting point (it's designed to work in a fire). Even in a house fire, the material will not melt and would not be a health hazard. But there are some safety things to remember - Never hold a smoke alarm in your hand to long - Never attempt to disassemble the radioactive elements housing or damage it as will release radiation still capable of causing a health hazard
What is an important use of the alpha particle?
The commonest use of alpha particles is probably in smoke detectors. The americium in the smoke detectors emits alpha particles. If smoke is present, it stops the alpha particles more efficiently than air, creating ions in the detection area of the device. The ions make the air more conductive, and the conductivity is sensed by the detector, which sets of the alarm. Alpha particles are also used in the radioisotope thermoelectric generators that power pacemakers and space probes.
How many types of smoke alarms can you get?
There are many types of smoke DETECTORS and self-contained smoke ALARMS. Some smoke detectors use ionizing radiation; others use photo-electric sensors. More sophisticated sensors use chemical reactions to detect specific types of smoke or to measure specific chemical composition and concentration of smoke. Photo-electric sensors are said to be more sensitive to smoldering fires (large particles) than ionizing detectors, meaning you may get an earlier warning from photo-electric.
How does smoke affect ionisation?
Smoke alarms use ionisation of air by an alpha source. A small pellet of the isotope of Americium sets up a current of a few micro Amps across an air gap and this is monitored by the electronic circuit. When smoke enters the ionisation cell the current is reduced as the smoke particles neutralise the charged ions. The dip in current causes the alarm to sound.
What are low levels of radiation used for?
Medical tracers and also for treating cancers. Some can be used for industrial x-rays. (They used to have very many uses that are now illegal - like luminous paints.) Smoke alarms use a tiny pellet of an alpha source - Americium. This isotope ionises the air within the detector to create a tiny standing current. Smoke disrupts this current and triggers the alarm. This use is controversial and its use is being phased-out in some parts of the world.
What is an Alpha Particle used for?
Correct me if I am wrong but I believe alpha rays do not exist. There are alpha particles, and gamma rays, but I do not think alpha rays exist. Alpha particles are most commonly used in smoke detectors, but have been used in the past of kill isolated areas of cancer cells.
What is a sentence for photoelectric?
There are two types of smoke alarms in general use for residential smoke alarms: photoelectricand ionization.There you go! If this is for homework try doing it yourself i am an assistant teacher at Canyon Lake Middle School and i encourage students to write their own sentences.
Why does a kidney scanner use gamma radiation rather than beta or alpha radiation?
since gamma radiation can penetrate more they are used in kidney scanners
How is radioactivity used in smoke detectors?
There are two types of smoke detectors:Photoelectric Smoke detectorsIonizing Smoke DetectorsIonization smoke detectors are more commonly used. The smoke detector uses an ionization chamber and a source of ionizing radiation to detect smoke.Alpha particles are emitted from from the chamber, which ionize the air, so that the air conducts electricity and a small current flows.If smoke enters the alarm, it absorbs the alpha particles causing the current to reduce, and the alarm sounds.Generally, smoke detectors use a weak source made of Americium-241 (241Am95).Note: Alpha particles are the nuclei of a Helium Atom (4He2).
