Thoron radiation

Thoron radiation was a type of radiation known to Federation science in the 24th century. The radiation was used in a variety of technologies for many different purposes.

Thoron radiation could be used to block sensors. Geordi LaForge used this technique in 2370 to scramble the sensors of a facility an away team from USS Enterprise (NCC-1701-D) was trying to infiltrate. The modified thoron burst allowed the team to beam in undetected. 

Thoron radiation could also signify the presence of some things; thoron emissions accompanied the appearance of a group of aliens who visited Deep Space 9 in 2369. And a Nechisti shrine, encountered by the crew of the USS Voyager in 2373, was marked by high levels of thoron radiation. 

The Ilari people used a type of weapon called a thoron rifle. 

Thorons could also be used in medical treatments; Portable thoron generators could be used to treat radiation burns, and thoron radiation could be used to treat individuals suffering from the memory virus, as it was deadly to the virus.