Observations of soft X-ray emission and plasma dynamics of a compact capillary discharge operated in xenon

In this work, we discuss experimental observations on the dynamics of a fast, low energy capillary discharge when operated in argon and its properties as an intense source of extreme-ultraviolet (EUV) radiation. The discharge pre-ionization and self-triggering were accomplished by the use of the hollow cathode effect. This allowed a compact size and low inductance discharge with multi-kA current level and a quarter-period of ∼10 ns at sub-Joule energy level. We used the novel moiré and schlieren diagnostics with a 12 ps laser to obtain the time evolution of the line electron density and to study the plasma dynamics. EUV spectroscopy and filtered diodes were also implemented to estimate the plasma temperature and density throughout the evolution of the discharge. EUV source size was measured by using a filtered slit-wire camera. We observed that EUV emission starts from a compressed plasma on axis during the second quarter-period of the current and continues until the fifth quarter-period. Ionization levels from Ar VII to X were observed. By comparing the EUV emission spectra with synthetic spectra, we found that at the onset of emission (∼7 ns), the plasma is well fitted by a single Maxwellian electron distribution function with Te ∼ 12 eV and ne ∼ 1017 cm−3. Close to peak emission (∼13 ns), plasma temperature and density increase to ∼20 eV and ne ∼ 1018 cm−3, respectively. However, in order to successfully match the experimental data, a two component electron distribution function was necessary. Later in time, a smaller fraction in the high energy component and higher temperature suggests homogenization of the plasma. The moiré and schlieren diagnostics showed multiple radial compression-waves merging on axis throughout the discharge; they are an important heating mechanism that leads to a period of severe turbulence at peak EUV emission. It was also observed that emission ceases when the axial maximum of the electron density collapses.

show abstract

Time-resolved study of the extreme-ultraviolet emission and plasma dynamics of a sub-Joule, fast capillary discharge

Valenzuela

Wyndham

Favre

2015

Physics of Plasmas

View full text Add to dashboard Cite

show abstract

Investigation on the characteristics of a two gap capillary discharge based on surface flash over ignition in atmosphere

Huang

Yang

Huo³

et al. 2016

Physics of Plasmas

View full text Add to dashboard Cite

In this paper, a two gap capillary (TGC) structure is presented and the corresponding driving circuit based on surface flashover ignition is designed to achieve reliable and repetitive discharge in atmosphere. The characteristics of the two gap capillary (TGC) discharge in low energy are investigated, of which the discharge energy is from 27 J to 432 J. With the rise of charging voltage, the delay of the weak capillary discharge and the main discharge both decrease. Meanwhile, the current flowing through the main gap and the plasma jet ejection are enhanced. The main gap resistance is about several hundreds of milliohms in the main discharge and rises gradually with the decay of the current. The long tail extinction is witnessed at the relatively low charging voltage of 0.5 kV and 1.0 kV, by which the pulse width of the discharge is extended. However, the discharge during the long tail extinction contributes little to the plasma jet ejection with negligible plasma jet velocity and low degree of the plasma ionization. The effective energy deposition efficiency on the main gap increases gradually with the charging voltage and reaches approximately 2 times higher than that of the traditional structure at the charging voltage of 2.0 kV. The series inductor in the circuit can restrain the development of the long tail extinction and increase the effective energy deposition efficiency. Thus, the discharge characteristics and the plasma ejection of TGC under the relatively low charging voltage are optimized.

show abstract

Numerical characterization of a discharge-based compact soft x-ray source operation in CO2 and Ar:He mixture

Samokhvalov

Sergushichev²,

Eliseev

et al. 2023

Physics of Plasmas

View full text Add to dashboard Cite

This paper presents numerical characterization of a recently developed compact soft x-ray source based on a nanosecond electric discharge in a gas-filled capillary. When operated in CO2 and Ar:He mixture, the source is capable of producing line radiation in wavelength ranges corresponding to the carbon (4.5–5.0 nm) and water (2.3–4.4 nm) transparency windows. Experimentally obtained trends in emission properties are analyzed using a two-temperature magnetohydrodynamic model, which utilizes mean ion approximation for calculation of basic properties of multicomponent plasma. Spatiotemporal distributions of plasma parameters were obtained for a range of gas pressures corresponding to the studied experimental conditions of the soft x-ray source. Peak values of electron density and electron temperature were analyzed and used to interpret the experimentally obtained trends in dependence of the source operation on inlet gas pressure.

show abstract

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

customersupport@researchsolutions.com

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Made with 💙 for researchers

Part of the Research Solutions Family.

Observations of soft X-ray emission and plasma dynamics of a compact capillary discharge operated in xenon

Cited by 3 publications

References 24 publications

Time-resolved study of the extreme-ultraviolet emission and plasma dynamics of a sub-Joule, fast capillary discharge

Time-resolved study of the extreme-ultraviolet emission and plasma dynamics of a sub-Joule, fast capillary discharge

Investigation on the characteristics of a two gap capillary discharge based on surface flash over ignition in atmosphere

Numerical characterization of a discharge-based compact soft x-ray source operation in CO2 and Ar:He mixture

Contact Info

Product

Resources

About