Optical characteristics of UV–VUV lamps on the electronic‐vibrational transitions of the hydroxyl radical pumped by a nanosecond capacitive discharge

Abstract

This paper presents the results of a study of UV and VUV low-pressure lamp pumped by nanosecond capacitive discharge. This lamp works on the mixtures of helium and argon with water vapor (H 2 O) or 'heavy' water (D 2 O). At the capacitive low-pressure lamp emission spectra are mainly narrow band 308 nm OH (A-X) and large band in the VUV spectral range: 140-200 nm OH (C, B, A). Found, that the increasing the partial pressure of H 2 O and D 2 O (>130-150 Pa) led to a decrease in the intensity of VUV radiation of hydroxyl radicals. In the transition from He/H 2 O mixture to He/D 2 O mixture, the optimal pressure of helium is decreased. Reduced partial pressure of argon led to increased intensity of radiation of hydroxyl in the VUV range. The study of emission characteristics of OD*-lamps on a mixture of He/D 2 O and the OH*-lamps on a mixture of He/H 2 O showed that the intensity of the bands OD (X, C, A) is 1.5 times larger than the intensity of the bands OH (X, C, A). The maximum absolute intensity of UV-VUV radiation of the lamp (at a frequency of 1000 Hz) reached 1 W.

Parameters of plasma of high-current nanosecond discharge in air with small admixtures of copper vapor

“…Для деяких застосувань в спектроскопії використовують «точкові» лампи досить інтенсивного ультрафіолетового (УФ)-випромінювання, в яких об'єм плазми розряду не переважає 3-5 мм 3 . Такі лампи складно виготовити, якщо джерелом збудження плазми служить бар'єрний чи ємнісний розряди [1,2]. Тому вони розробляються на основі перенапружених розрядів наносекундної або субнаносекундної тривалості на парах металів [3,4].…”

Characteristics of Bipolar Nanosecond Discharges in Air Formed in the Electrode System “BLADE-SURFACE of Nonmetallic Liquid -BLADE”

“…Recently, intensive use of various gas-discharge sources of ultraviolet (UV) radiation in medicine, microbiology, chemistry, sanitation and ecology has been observed [1][2][3][4][5][6][7][8][9]. Promising for these purposes is the use of "cold" plasma jets, which are also formed mainly in different gas-discharge devices [10].…”

Parameters of Nanosecond Overvoltage Discharge Plasma in a Narrow Air Gap between the Electrodes Containing Electrode Material Vapor

“…Unlike UV and VUV lamps with the pumping by a barrier or capacitive discharge [7,8], "pointsource" UV lamps on the basis of a vapor of chemical elements can have very small plasma volumes of about 1-5 mm 3 at a pulse power of radiation emission larger than 1 W. Therefore, they are applied to the calibration of spectral devices and various optical elements operating in the UV spectral interval. They are also promising in nanotechnology, medicine, and biology.…”