INDUSTRY - Uses & Properties

Source:  INDUSTRY - Uses & Properties    Tag:  radioisotope uses

Properties & Uses:

Properties of Americium-241 impact the way in which it is used, smoke detectors being the main industrial use. 

Below lists the relationship between Am-241 Properties and Uses:

Atomic mass of 241.056823
This means various forms of this element can occur, known as isotopes. Different isotopes have slightly different properties to fulfil different uses.
Appearance: Silver/metal colour, crystalline, Its boiling point is 2607°C and melting point is 994°C
As Am-241 boiling point and melting point are extremely high, the natural state will be a solid. The isotopes chemical form is Americium Oxide (AmO2)
All isotopes of Am-241 are radioactive and decay by alpha emission and also gamma rays.
The use of this isotope is widely used in domestic and industrial smoke detectors.
Other uses include:
  • Medical Diagnosis
  • Fluid-density gauging
  • Aircraft fuel gauge (Device used to indicate the fuel level in the tank)  
  • Thickness gauge in glass industry

A mixture of Am-241 and Beryllium are capable of emitting neutrons
These neutrons can be used for research.

Future Uses: European Space Agency are considering Am-241 to be used in their space probes

Smoke Detectors: 
Americium-241 main use is in industrial and domestic smoke detectors. So how do they work?

Americium-241 has a relatively long half-life of 432 years making domestic smoke detectors a reliable radioisotope that will last generations without the need to replace it. The alpha particles emitted by the Am-241 isotope collide in the ionization chamber with oxygen and nitrogen from the air, to create ions. Two metal plates are positioned within the ionisation chamber, one positively charged, the other negative. 

How Am-241 works in a smoke detector
The charged ions attract themselves to these metal plates creating a small electric current as they move towards the positive or negative charged plate. As smoke enters the ionisation chamber, it disrupts the current as smoke particles attach to the charged ions and neutralizing them. As these particles are now at a neutral electrical state, they will no longer be attracted to the charged metal plates, therefore reducing the current. Once the current has dropped significantly, the alarm is triggered.