Caesium metal is used in the following applications:
• As a “getter” in low-voltage electron tubes, to scavenge trace amounts of oxygen.
• Caesium 137, recovered from waste of atomic plants is used as a gamma-ray emitter; it has a half-life of 33 years.
• It finds use also in teletherapy.
• Caesium is used in atomic clocks, where a loss of 5s over 300 years is achievable.
• Caesium may also be used as a catalyst for hydrogenation of certain organic compounds.
• It has also been considered for in ion propulsion systems, for outer space uses.
• In photoelectric cells as a photosensitive deposit on the cathode. The caesium metal in this application is also used in the infrared signalling lamp (known as a photophone) in this application it gives infrared waves without visible light.
Caesium compounds have been implemented on filaments of radio tubes to increase sensitivity.