Electron Density Measurements from Stark Broadened Emission in a Sodium Plasma Produced by Laser Resonance Saturation
Abstract
Electron Stark broadening of the 42D--32P multiplet transition in a sodium plasma produced by laser resonance saturation has provided a means of undertaking the first spatial measurements of the free electron density across and along the plasma channel created in sodium vapor of density 1015--5×1016~cm−3. From these measurements and measurements of the neutral sodium density within a heat sandwich oven, we are able to deduce the corresponding electron temperature. These temperatures compare favourably with the electron temperature estimated from a Boltzmann analysis of line intensities and suggest that a highly ionized (>10\%) plasma of electron temperature <6000K can be produced within 100~ns of laser excitation from a laser of modest irradiance (106--107~Wcm−2). The experimental results are in reasonable agreement with a recently developed 3-dimensional model which predicts a decrease in the degree of ionization along the path of the laser beam as a result of significant depletion of laser energy. These experimental results demonstrate that this LIBORS code is capable of predicting the 3-dimensional nature of this new mode of laser ionization with reasonable accuracy, and may also explain the low electron temperatures and free electron densities observed by other research teams.
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BibTeX
@misc{cappelli2026electron,
title = {{Electron Density Measurements from Stark Broadened Emission in a Sodium Plasma Produced by Laser Resonance Saturation}},
author = {Mark A. Cappelli},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.36085},
eprint = {2609.36085},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.36085},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Electron Density Measurements from Stark Broadened Emission in a Sodium Plasma Produced by Laser Resonance Saturation
AU - Mark A. Cappelli
PY - 2026
DA - 2026/09/28
PB - arXiv
DO - 10.48550/arxiv.2609.36085
UR - https://arxiv.org/abs/2609.36085
AB - Electron Stark broadening of the 4^2D--3^2P multiplet transition in a sodium plasma produced by laser resonance saturation has provided a means of undertaking the first spatial measurements of the free electron density across and along the plasma channel created in sodium vapor of density 10^15--5×10^16~cm^−3. From these measurements and measurements of the neutral sodium density within a heat sandwich oven, we are able to deduce the corresponding electron temperature. These temperatures compare favourably with the electron temperature estimated from a Boltzmann analysis of line intensities and suggest that a highly ionized (>10\%) plasma of electron temperature <6000K can be produced within 100~ns of laser excitation from a laser of modest irradiance (10^6--10^7~Wcm^−2). The experimental results are in reasonable agreement with a recently developed 3-dimensional model which predicts a decrease in the degree of ionization along the path of the laser beam as a result of significant depletion of laser energy. These experimental results demonstrate that this LIBORS code is capable of predicting the 3-dimensional nature of this new mode of laser ionization with reasonable accuracy, and may also explain the low electron temperatures and free electron densities observed by other research teams.
ER -