Pulsed Xenon Lamp Research Articles

Development of an Ion Mobility Spectrometer Based on a Pulsed Photoelectric Effect Ionization Source.

Ion mobility spectrometry (IMS) is a compact and sensitive trace gas analysis instrument that ionizes the sample into ions for detection. Typically, an ion gate is used to cut the continuous ion beam into ion packets for separation and detection. However, commonly used ion gates suffer from complex structures or low ion transmission rates, making the gateless IMS a viable alternative. In this study, an IMS based on a pulsed photoelectric effect ionization source was designed. The photoelectrons were generated by irradiating a photoelectric material with a back-illuminated pulsed xenon lamp. This allows for low-energy photoelectron generation and the production of simple reactant ions (O2-(H2O)n) and thus negative product ions. The photoelectron current generated by this ionization source was analyzed, which can reach an intensity of a few microamperes and can be converted into an ion signal exceeding 10 nA. The introduction of the pulsed photoelectric effect ionization source makes it possible to generate separate ion packets and complete ion injection when a constant electric field is maintained in the ionization region. And with an assisted pulsed electric field in the ionization region, the resolving power of the system can be effectively improved to 1.85 times that of the constant electric field. The IMS developed in this study was used for the detection of common volatile hazardous chemicals, yielding effective results. The detection limit for phenol was below 1 ppb, and the dynamic response range exceeded 1 order of magnitude, which implies the potential applications of this IMS to detect substances with high electron affinity, such as explosives detection in public safety.

Comparison of the Effectiveness of UV Radiation Sources for Wastewater Treatment of Terephthalic Acid

The following sources of UV radiation used for photochemical wastewater treatment are considered: medium and low pressure mercury lamps, KrCl and KrBr excimer lamps, and a pulsed xenon lamp. On the example of photolysis of terephthalic acid (TPA), various parameters were calculated that allow quantitative comparison of UV sources: radiation efficiency, quantum output of the process, specific energy and operating costs for the destruction of the target pollutant.

Photophysics of singlet oxygen generation in chitosan films with viburnum fruit extract (Viburnum opulus L.) under the influence of plasmons on a modified titanium surface

Subject of study. This study investigates the luminescence spectral and kinetic features of singlet oxygen generation in chitosan microfilms (10 µm thick) embedded with an extract of viburnum fruit (Viburnum opulus L.). These films were deposited on both glass and gold film (80 µm thick), with the gold film electrochemically deposited on a rough, modified titanium surface. Aim of study. The aim was to determine the primary photophysical patterns of singlet oxygen dynamics in chitosan films containing viburnum fruit extract, following pulsed monochromatic photoexcitation by a structured titanium surface coated with electrochemically deposited gold. Method. The films were investigated in the visible and near-infrared regions using fluorescence techniques. The luminescence lifetime of Viburnum opulus L. flavonoids in the nanosecond range was measured using multichannel photon counting with a picosecond diode. The lifetime of the flavonoid triplet states and singlet oxygen phosphorescence in the studied extract in the microsecond range under excitation by a pulsed xenon lamp were also recorded. Main results. Long-lived delayed annihilation fluorescence of Viburnum opulus L. flavonoid molecules in the 590 nm spectral region, along with luminescence at 1272 nm attributable to singlet molecular oxygen, were observed. A comprehensive kinetic analysis was performed, considering the rate constants of photophysical processes involving singlet oxygen in films with viburnum fruit extract on rough gold surfaces under conditions of sample saturation with molecular oxygen. Stable generation of singlet oxygen was achieved in the chitosan microfilms containing viburnum fruit extract. Practical significance. The findings of this study can be applied to biological methods for cancer treatment.

Increasing the shelf life of packaged bakery products by their processing of broadband optical radiation of a pulsed xenon lamp

Pulsed xenon lamps generating a wide spectrum of radiation of the megawatt range are sources of a new generation of biocidal radiation, which shows potential in the food industry. The article presents the results of studies of the efficiency of pulsed xenon lamp radiation in relation to antifungal treatment of bakery products in sealed plastic packaging in order to increase their shelf life. The object of research was commercial samples of bakery products packed in polypropylene film. The samples were processed by radiation from a pulsed xenon lamp with power of 300 watts. It is shown that irradiation of bakery products samples in the mode with an integral fluence of broadband optical radiation of 10 J/cm2 and a dose of short-wave UV radiation of 0.6 J/cm2 makes it possible to increase their shelf life several times (on average 2 times for most types of samples) compared with untreated samples. General conclusion: optical radiation of a pulsed xenon lamp has a pronounced antifungal effect and is able to inhibit the development of mold fungi on bakery products, even when they are processed in packaged form. The obtained results can be used in the development of equipment of antifungal treatment of bakery products.

Preclinical Studies of the Antimicrobial and Wound-Healing Effects of the High-Intensity Optical Irradiation “Zarnitsa-A” Apparatus

In this paper, a new approach to treating infected wounds is proposed. It is based on treating the wound surface with high-intensity pulsed optical radiation with a continuous spectrum, continuously covering the entire UV range (from 200 to 400 nm) and the visible and near-infrared regions of the spectrum. A pulsed xenon lamp is used as a radiation source. A description of the design and technical characteristics of the device, “Zarnitsa-A”, is presented, implementing the proposed medical technology for wound therapy. The results of our studies of the apparatus in vitro and in vivo are also presented. The article shows that exposure to the apparatus leads to pronounced bactericidal- and wound-healing properties. The apparatus’s action reliably provides higher rates of wound healing compared with only a typical antibacterial or wound healing agent, such as “levomekol” ointment.

Исследование характеристик U-образного плазменного канала импульсных ксеноновых ламп

The paper presents main results of investigating electrical parameters and characteristics of the pulsed xenon lamp ultraviolet radiation with a U-shaped plasma channel and caprod current leads. The gas-discharge lamp design feature suggests presence of the ballast transelectrode volumes contributing to the xenon escape from the discharge and the radiation acting from one part of the U-shaped plasma channel on the other. Literature sources devoted to the specified phenomena were analyzed. Factors influencing the xenon plasma thermophysical state were established. Due to the lack of techniques for registering the pulsed radiation in a narrow spectral range of 200--300 nm, measurement techniques and investigation hardware were considered in detail. The time interval for establishing the gas-dynamic equilibrium in a pulsed xenon lamp in the process of its entry into the nominal operating mode was determined by calculation and experiment. Studies of the Vt transelectrode volume effect on characteristics of the pulsed xenon plasma were carried out in the range of 0.16 < Vt /Vi < 0.3. It was established that the possible factors leading to a decrease in the current density and intensity of the UV radiation included the modes of electrical supply and evaporation of the quartz shell limiting the discharge. It was shown that self-radiation return in plasma contributed to an increase in the current density of the pulsed xenon lamp

Effects of Electrical Pulse Width and Output Irradiance on Intense Pulse Light Inactivation.

The effects of electrical pulse width and output irradiance on the inactivation effect of intense pulse light (IPL) are studied in this paper. The measured radiant efficiency of pulsed xenon lamp can be more than 50%, and its irradiance can reach levels 100-times greater than that of a low-pressure mercury lamp. Staphylococcus aureus is used in inactivation experiments. When the irradiance and dose are both constant, there is no significant difference in inactivation efficiency when the pulse width is changed. However, a narrow pulse width corresponding to high irradiance at the same single-pulsed dose displays better inactivation effect. Experimental results are compared between the xenon lamp and low-pressure mercury lamp. The reduction factor (RF) value of the xenon lamp is more than 1.0 higher under the condition of both the same dose and irradiance. In order to achieve the same RF value, the dose of continuous-wave light must be at least three-times greater than that of pulsed light. The spectral action of the pulsed light is also studied. It is confirmed that UVC plays a major role across the whole spectrum. The experimental results show that extreme high-pulsed irradiance presents the main contributing factor behind the excellent bactericidal effect of IPL.

Ultraviolet disinfection of activated carbon from microbiological contamination

This article aims to investigate the effectiveness of the use of ultraviolet radiation or a combination of ultraviolet radiation and ozonation in the inactivation of microorganisms in activated carbon "Silcarbon". Several experimental studies where ultraviolet light, a combination of UV radiation, and ozonation were used have been performed to disinfect "Silcarbon" from microbiological contaminants. Experimental results have shown that with pulsed xenon lamps and low-pressure mercury ozone lamps, satisfactory results can be obtained in which the total amount of yeast and mould fungi range from 50 CFU/g to 75 CFU/g. It is advisable to continue the study of powder materials, including drugs, on the content of microbiological contaminants to assess their compliance with regulatory requirements. The application of the proposed approach to the inactivation of microorganisms allows one to obtain a safe sorbent on the content of microbiological indicators and can be successfully used in any other field to disinfection powder materials using different modes of UV irradiation. The originality of the article's results proposes a method of disinfection of the sorbent "Silcarbon" from moulds and yeasts for therapeutic purposes in medicine.

Computational analysis model of intense pulsed sintering of silver nanoparticles

Intense pulsed light sintering uses a high-power pulsed xenon lamp to release large amounts of energy and promote the growth of sintered necks between nanoparticles in additive manufacturing. However, the process results in poor stability of the sintering effect on conductive patterns and easily damages the target materials. An analysis model was developed in this study to investigate the mechanism of intense pulsed sintering. The sintering process was divided into pre-sintering and formal sintering. In pre-sintering, the conductive pattern is described by the porous volatilization model based on Darcy's fluid equation to calculate the solvent phase change volatilization state, whereas a multi-scale analysis model was established for the formal sintering process. First, a molecular dynamics model was used to analyze the sintering state of nano-silver clusters in a variable temperature field to calculate the time-varying parameters. Second, from a finite element model, the intense pulsed sintering temperature field was constructed for different sintering parameters and applied to the two-phase flow model of sintering nano-silver particles to calculate the sintering process state of nano-silver particles. The relationship between the intense pulsed sintering parameters and the sintering state was revealed, thus providing a reliable theoretical basis for the sintering process to improve sintering stability.

ОБ ОЦЕНКЕ ЭФФЕКТИВНОСТИ ПРОЦЕССА ВЫСОКОИНТЕНСИВНОГО ОКИСЛЕНИЯ

The EEO parameter is commonly used as a figure-of-merit of ultraviolet-based advanced oxidation processes (UV AOPs). It represents the energy input into the UV AOPs that can achieve an order of magnitude decrease in the target contaminant concentration in a unit volume. This paper focuses on factors, that influence on the EEO parameter and should be reported with it to compare the efficiency of different reactors or UV AOPs: the identity and concentration of the target pollutant, as well as the concentration of scavengers; the amount of hydrogen peroxide or other oxidizing agent, source of UV radiation etc. Decays of phenol, sodium dodecyl sulfate and petroleum products in UV AOP were used to show how various conditions affect on the EEO parameter. The studies were carried out on model solutions with an initial concentration of pollutants of 10 mg/l. As a source of ultraviolet radiation, a pulsed xenon lamp was used. It has a continuous emission spectrum in the range of 200 – 1000 nm, the average energy consumption was about 200 W, the radiation energy in the range of 200–300 nm was 2.7 J. Hydrogen peroxide was used as an oxidizing agent, it concentration varied from 10 to 340 mg/L. The modified parameter of UV AOP efficiency is proposed. It considers electrical energy input with reagents consumption. It is proposed to express the costs of the oxidant in physical values and include them in the modified parameter with a weighting factor.

The organization of pre-clinical studies of bactericidal and wound healing effects of the impulse photoherapy device "Zarya"

The purpose of the study is to determine therapeutic effectiveness of the pulsed high intensity optical irradiation device "Zarya" exemplified by treatment of model wounds in laboratory animals and to compare with traditional methods of wound treatment. The prototype of "Zarya" device was used whose operating principle was based on pulsed irradiation of affected areas with high intensity optical radiation in continuous spectrum generated by pulsed xenon lamp. The therapeutic effect of the "Zarya" device was compared with effectiveness of the certified medical ultraviolet irradiator based on low-pressure mercury lamp and also with known wound-healing and antibacterial medication Levomekol ointment. The mature male rats of Wistar line were used in the study. The animals were distributed to 4 groups: group 1 was irradiated by "Zarya" device, group 2 was irradiated by low-pressure mercury lamp, group 3 was treated with Levomekol ointment and group 4 was exposed to no exposure. The linear wound was modeled according to the standard method under ether anesthesia. The therapeutic procedures were applied daily during 7 days. The bactericidal effect was studied on the basis of smears from wound onto flora on the 2nd, 5th and 7th day. On the 8th day the animals were subjected to euthanasia. It was established that "Zarya" device application permits to reduce considerably both duration of therapeutic procedures and therapy course in general and also to achieve more pronounced bactericidal effect. The obtained data is supposed to be used for development of program of clinical trials.

Wireless, Accumulation Mode Dosimeters for Monitoring Pulsed and Non-Pulsed Germicidal Lamps

Mitigating the spread of infectious diseases such as the one associated with the COVID-19 pandemic demands simple and effective disinfection techniques. Ultraviolet germicidal irradiation (UVGI) is one such method, in common use for decontamination of hospital rooms. Practical technologies designed to monitor UVGI ensure the delivery of sufficient doses for germicidal efficacy. Existing UVGI dosimeters rely on intermittent measurements of intensity as the basis for a numerical integration scheme that approximates dose. Traditional devices are ineffective, particularly with pulsed UVGI lamps that emit pulses of light with durations shorter than the interval of measurement. Here, we present a compact, accumulation mode dosimeter (AMD) that detects continuously, as opposed to intermittently, at single or multiple UVGI wavelengths. The AMD utilizes an array of photodiodes and supercapacitors to passively transduce and capture photocurrent generated by UVGI without the use of external power. The accumulated voltage across the supercapacitors then serves as a measure of UVGI dose. A key result is that sampling intervals of AMD do not constrain measurement accuracy. When implemented with a wireless transponder, AMD supports a light-adaptive sampling scheme designed to adjust the sampling interval to the intensity and period of UVGI exposure. Compared to time-based sampling schemes adopted by conventional sensors, light-adaptive approaches autonomously optimize battery life by minimizing current consumption during periods of low or no UVGI. Benchtop studies of the use of this technology with pulsed Xenon lamps (pulse ~5 ms) sampled at long intervals (>1s) highlight the key features of operation. Demonstration of AMD during UVGI of E. Coli cultures represents an example in dose dependent effects on disinfection.

Activation of film growth on indium phosphide by pulsed photon treatment

Photon activation of various physicochemical processes by the radiation of powerful pulsed xenon lamps (radiation range of 0.2-1.2 µm) is one of the promising areas of material science. The aim of this study was to determine the effect of preoxidative pulsed photon treatment on the process of thermal oxidation of indium phosphide with a nanosized layer of V2O5 on the surface, as well as its effect on the composition and morphology of the formed films. We determined the optimal mode of pre-oxidative pulsed photon treatment of magnetron-formed V2O5/InP heterostructures with a radiation density of 15 J/cm2. By laser and spectral ellipsometry methods, photon activation of V2O5/InP before thermal oxidation was found to increase the thickness of the formed films practically twofold. X-ray diffraction analysis confirms the intensification of the phosphate formation process. The morphological characteristics of the films were determined by atomic force microscopy.Pre-oxidative pulsed photon treatment with an optimal radiation density of 15 J/cm2 activates the thermal oxidation of V2O5/InP heterostructures. It is associated with the formation of new active centres and accelerated rearrangement of chemical bonds in the intermediate complexes of the V2O5 catalyst with semiconductor components

Research of the polyethylene packaging layer structure change in contact with a food product at exposure to ultraviolet radiation

The sanitary and hygienic safety of modern packaging is determined by the layer of packaging material in direct contact with the food product. This layer in most cases is a synthetic polymer of the polyolefin class — low density polyethylene. This material is used as a stand-alone packaging and in multilayer and combined packaging materials. During thermal and photooxidation, compounds can form in it that negatively affect the safety of the package, which can migrate into the product. Food technologies use methods of disinfecting packaging materials and packaging before filling or bottling products. These methods include ultraviolet irradiation of the surface, which has a bactericidal effect. Using spectral methods of analysis, researches have been carried out on changes in the polyethylene layers structure in the film’s composition, multilayer films and combined packaging materials when exposed to pulsed ultraviolet radiation in a wide spectral range (irradiation with a pulsed xenon lamp). Deformations of polyethylene macromolecules chemical bonds on the surface and boundary layers under the influence of pulsed UV-irradiation have been revealed. The IR spectra of ATR (Attenuated Total Reflection) were obtained, the analysis of which showed that the monofilm is subject to the greatest destructive effect, as evidenced by the appearance of characteristic absorption bands responsible for the formation of aldehyde, ketone groups, as well as for the polymer chain termination. It is shown that the use of food soot in the composition of multilayer packaging films blocks their photo destruction. Upon irradiation of a combined material based on cardboard intended for bottling milk, an absorption band was found in the spectra, which is responsible for the onset of the destruction process with the formation of aldehyde and carboxylate groups with the formation of aldehyde and carboxylate groups.Comparison of changes in structure in three different packaging objects containing a polyethylene layer shows the feasibility and necessity of using combined and multilayer materials for food products packaging, in which, even under extreme UV-irradiation, there are practically no photo destruction processes, which is confirmed by spectral researches.

Research of pulsed Xenon lamp power supply based on STM32

Novel coronavirus pneumonia affects the health of people all over the world. In this study, UV pulse high-light sterilization technology was used to combat coronavirus. The light source of the ultraviolet pulsed high-light disinfection robot is a kind of high-brightness flash light source using pulsed xenon lamps as the output load. This paper developed a pulsed xenon lamp power supply with a high-voltage pulse synchronous trigger function, a DC charging voltage of 1kV-3kV, an output pulse current range of 1kA-3kA, and a pulse width of 50μS for a pulsed xenon lamp with a 196mm×Φ10mm and a resistivity of 12Ω⋅A1/2. This paper presented the experimental results of charging voltage of 1kV, output pulse current peak value of 1kA, and pulse width of 50μS. The power supply design was based on the phase-shifting voltage regulation mode of UC3825 control power MOS tube, through the sampling isolation module and the closed-loop feedback formed by STM32 control, the energy storage capacitor was linearly charged through the DC voltage sampling and voltage regulation control module; the trigger pulse signal was generated by the SCR switch, and the xenon lamp was turned on and emits flash light after the pulse transformer was boosted. The sample test results verified the feasibility of the power supply design principles and technical solutions.

Spatial distribution of radiation from pulsed xenon gas-discharge lamps with different configurations of the plasma channe

The paper presents the results of studies of the spatial distribution of radiation from pulsed xenon lamps with a straight and U-shaped plasma channel configuration in the ultraviolet and near infrared spectral range. The dependence of the shape of the indicatrix on the design fea-tures of the flash lamp,the absorption coefficients of the plasma and the envelope limiting the discharge is shown.

Xenon lamp control signal and drive circuit design of Er: YAG laser

When the Er: YAG laser pumped by a xenon lamp emits laser light, the energy, frequency and pulse width of the emitted light are closely related to the discharge of the xenon lamp. This article uses the 8MHz external crystal oscillator that comes with the STM32F4 development board, generates a clock source through frequency division and frequency multiplication, and configures a pulse width modulation (PWM) signal to control the laser. Since the signals sent by the development board are weak signals, it is necessary to design a corresponding drive circuit to amplify the power of the signal. Finally, the voltage of the pulsed xenon lamp is adjustable from 0 to 1400V, and the pulse width is adjustable from 50 to 300μs to achieve stable laser output.

Design and characteristics of a modular integrated power supply for the system of flashlamp-pumped in inertial confinement fusion

• A 1.46 MJ capacitive pulsed power supply is designed by using the pulse thyristors. • The synchronous triggering of multiple sets of thyristors enables high current output of the pulsed power supply. • The high gate trigger system is developed to control the synchronous conduction of the thyristors of each module. • Simulation and project experience show that the high-probability failure will not affect the other components in the power supply. In order to study the adaptation of the semiconductors for the special power supply application, a capacitive pulsed power supply is designed by using the pulse thyristors. The modular integrated method is adopted to redesign the main circuit of the power supply. The synchronous triggering of multiple sets of thyristors enables high current output of the pulsed power supply, which can avoid excessive current passing through the thyristors and eliminate current-sharing measures of the thyristors. Applying the fast switching MOSFET and magnetic induction of pulse transformer, a set of high gate trigger system is developed to control the synchronous conduction of the thyristors of each module. The simulation and experimental results show that most of the faults occurring during the operation of the pulsed power supply can be limited by protection devices. Practical operation indicates that the pulse power supply can provide specific required pulse current and energy for the pulsed xenon lamp. The design method of the pulsed power supply can provide a reference for the design of the pulsed power supply, and lay a foundation for the higher capacitive energy storage application.

Flash Lamp Processing-Activated Structural Transformations in Foil of a Pd–Cu Solid Solution

The β $$ \rightleftarrows $$ α phase transformations in foil of the Pd–52 at % Cu solid solution prepared by rolling have been studied using X-ray diffractometry and resistivity measurements during thermal heating–cooling cycles or lamp processing (LP) using light from high-power pulsed xenon lamps, followed by cooling. The results demonstrate that complete ordering of the two-phase (α + β) as-prepared (as-rolled) foil follows the sequence (α + β) → β → α → β in the first heating–cooling cycle and β → α → β in the second and subsequent cycles. When a radiative energy critical for a given thickness of foil with an ordered structure is delivered to the foil surface, an irreversible β → α phase transformation occurs, whose rate can be three orders of magnitude higher than the rate characteristic of the disordering process during Joule heating. After LP, the reversibility of the β $$ \rightleftarrows $$ α phase transformations, inherent in the initial, ordered structure, is observed in a second thermal cycle: heating to 700°C and cooling. The sequence of phase transitions is α → β → α → β in the first cycle and β → α → β in the second and subsequent cycles. The localization of light in the skin layer and finite thermal conductivity offer the possibility of producing a structure with a phase composition gradient at subcritical irradiation times. The fact that the LP-stabilized α-phase persists up to 300°C makes it possible to compare the mechanical properties of foil samples having identical elemental compositions but different (ordered and disordered) structures.

Experimental study of the light source characteristics for the NH3 concentration detection

Ammonia (NH3) is the most abundant alkaline gas in the atmosphere, and the cause of the majority of secondary particles in PM2.5 and the catalyst for the formation of atmospheric haze. Therefore, it is of great environmental significance to monitor NH3 concentration. This paper introduces the principle of NH3 concentration detection based on Lambert-Beer's law and sets up an experimental platform. Then the experimental study on the characteristics of Hamamatsu L9456-1 pulse xenon lamp for the NH3 concentration detection has been carried out. The fluctuation of light source, integral time of light source collection, average times and other practical problems occurred in the experiment have been studied carefully, and then the corresponding solutions have been put forward respectively. Finally, the most reasonable operating parameters of light source have been obtained. The experimental results have been applied to the absorbance detection of NH3 with different concentrations. The measurement results show that using the parameters obtained in the study to set the working index of L9456-1 pulse xenon lamp can obtain relatively accurate NH3 absorbance, which can lay a good foundation and be fully prepared for the entire detection system to measure the NH3 concentration accurately.