vacuum ultraviolet radiation
vacuum ultraviolet radiation[′vak·yəm ¦əl·trə′vī·lət ‚rād·ē′ā·shən]
Ultraviolet radiation with a wavelength of less than 200 nanometers; absorption of radiation in this region by air and other gases requires the use of evacuated apparatus for transmission. Abbreviated VUV radiation. Also known as extreme ultraviolet radiation (EUV radiation).