Radiation efficiency of Ar torch short plasma near 70~140 A

When reduction of waste and dissolution of iron are carried out by using arc plasma, one needs to reduce the arc radiation power, because there are some cases where radiation can damage the furnace wall. On the other hand, one can use it as a clean source for heating materials. The authors measured the radiation power from plasma torches. The radiation power increased in proportion to the 1.8-2.0 th power of the current. The radiation power in a unit length increases with the apparent plasma length. The radiation efficiency is 41% for an apparent plasma length of 3 cm and 31% for the whole plasma length of 3 cm due to a wall-stabilized arc model at 100 A