<unk>  are part of the electromagnetic spectrum comprising low energy (ultrasoft) X-rays. These were first investigated by Gustav Bucky in 1923 using a cathode vacuum tube with a lithium borate glass window, which he labeled<unk>  as he believed that the biological effects resembled those of UV light and traditional X-rays and hence were on the border between the two<unk>  = border in German). These<unk>  are also known as Bucky<unk> .<unk>  are produced by specially calibrated X-ray machines generally operating in the 10 to 30 kV range to produce X-rays with HVL less than 0.035 mm in aluminum. (HVL is half-value layer, and refers to a thickness of a given material that will cut the X-ray flux by 50%).<unk>  are absorbed by air and therefore treatments must be given at fixed distances for which the machine has been calibrated. In human tissue<unk>  have a half-value depth of 0.5 mm and are essentially absorbed within the first 2 mm of skin. The exact mechanism of action is unknown but it does have effects on the Langerhans cells in the epidermis.
Grenz rays
Wart
Xilloc
Bili light
Earwax
Ultraviolet index
Ionaco
BoRit Asbestos