“…Atmospheric-pressure non-equilibrium plasmas (APNEPs) can maintain a high electron temperature while maintaining a low gas temperature, unlike thermal plasmas such as arc discharge and discharge plasmas, which typically have elevated gas temperatures. Owing to this property, it is possible to perform processes such as surface processing [1,2], sterilization [3], and tooth bleaching [4,5] without damaging the objects. Therefore, APNEP has attracted considerable research attention in recent years in various fields such as medicine [4][5][6][7], transition of electrons from the upper to lower levels, whereas the continuum spectrum is the bremsstrahlung emitted by the collision of electrons and atoms [13].…”