Observation and Characterization of Trends in the Ionization of the Warm Absorber Photoionized Plasma Experiment at Z
type: CreativeWork
description: Many types of astronomical systems containing extremely bright and energetic radiation sources create photoionized plasmas from the material in their vicinity. This class of plasma is notable for high degrees of ionization while having relatively low temperatures, wherein photon-driven atomic processes dominate over collisional processes in the atomic kinetics. The systems in which these exist are complex, and astrophysicists endeavoring to understand them utilize modeling software created to simulate the physics in such plasma environments. Due to the extreme nature of the conditions involved, it has only recently become feasable to create adequate radiation sources in the laboratory capable of driving photoionized plasmas in an effort to test the physics models employed by astrophysicists.We are engaged in one such experiment utilizing the Z Machine at Sandia National Laboratories, which exploits the intense, broadband, x-ray radiation generated by the collapse of a z-pinch to drive neon gas, creating a photoionized plasma to study in the laboratory. The Warm Absorber Photoionized Plasma Experiment uses a cm-scale gas cell placed several centimeters from the z-pinch to contain neon gas of atom number densities 10$^{17}$ -- 10$^{18}$ cm$^{-3}$. Windows along the line of sight to a spectrometer allow (1) the radiation from the z-pinch to pass through the cell and drive the system and (2) a spectral measurement of K-shell line absorption by neon using the z-pinch as the backlighter. The TREX elliptical crystal spectrometer collects time-integrated or time-gated spectral data allowing characterization of the plasma conditions by spectral analysis. This experiment is notable in its flexibility to vary the x-ray flux $F$ and electron density $n_e$, together or separately. This allows a systematic study of their effect on plasma conditions covering, for the first time with one experimental platform, an order of magnitude in the ionization parameter $\xi \propto F/n_e$. T…
abstract: Many types of astronomical systems containing extremely bright and energetic radiation sources create photoionized plasmas from the material in their vicinity. This class of plasma is notable for high degrees of ionization while having relatively low temperatures, wherein photon-driven atomic processes dominate over collisional processes in the atomic kinetics. The systems in which these exist are complex, and astrophysicists endeavoring to understand them utilize modeling software created to simulate the physics in such plasma environments. Due to the extreme nature of the conditions involved, it has only recently become feasable to create adequate radiation sources in the laboratory capable of driving photoionized plasmas in an effort to test the physics models employed by astrophysicists.We are engaged in one such experiment utilizing the Z Machine at Sandia National Laboratories, which exploits the intense, broadband, x-ray radiation generated by the collapse of a z-pinch to drive neon gas, creating a photoionized plasma to study in the laboratory. The Warm Absorber Photoionized Plasma Experiment uses a cm-scale gas cell placed several centimeters from the z-pinch to contain neon gas of atom number densities 10$^{17}$ -- 10$^{18}$ cm$^{-3}$. Windows along the line of sight to a spectrometer allow (1) the radiation from the z-pinch to pass through the cell and drive the system and (2) a spectral measurement of K-shell line absorption by neon using the z-pinch as the backlighter. The TREX elliptical crystal spectrometer collects time-integrated or time-gated spectral data allowing characterization of the plasma conditions by spectral analysis. This experiment is notable in its flexibility to vary the x-ray flux $F$ and electron density $n_e$, together or separately. This allows a systematic study of their effect on plasma conditions covering, for the first time with one experimental platform, an order of magnitude in the ionization parameter $\xi \propto F/n_e$. T…
author: Mayes, Daniel
keywords: Neon, Photoionized plasma, X-ray Spectroscopy
date published: 2020
date modified: 2026-07-27T21:47:25Z
provider: University of Nevada - Reno
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Nevada - Reno

PropertyValue
property ID: Handle
value: http://hdl.handle.net/11714/7725