Volumetric plasma source development and characterization.

Technical Report · Mon Sep 01 04:00:00 EDT 2008

DOI:https://doi.org/10.2172/942062· OSTI ID:942062

Crain, Marlon D ^[1]; Maron, Yitzhak ^[2]; Oliver, Bryan Velten; Starbird, Robert L ^[1]; Johnston, Mark D; Hahn, Kelly Denise; Mehlhorn, Thomas Alan; Droemer, Darryl W ^[1]

---

1. National Security Technologies, LLC, Las Vegas, NV
2. Weizmann Institute of Science, Rehovot, Israel

The development of plasma sources with densities and temperatures in the 10{sup 15}-10{sup 17} cm{sup -3} and 1-10eV ranges which are slowly varying over several hundreds of nanoseconds within several cubic centimeter volumes is of interest for applications such as intense electron beam focusing as part of the x-ray radiography program. In particular, theoretical work [1,2] suggests that replacing neutral gas in electron beam focusing cells with highly conductive, pre-ionized plasma increases the time-averaged e-beam intensity on target, resulting in brighter x-ray sources. This LDRD project was an attempt to generate such a plasma source from fine metal wires. A high voltage (20-60kV), high current (12-45kA) capacitive discharge was sent through a 100 {micro}m diameter aluminum wire forming a plasma. The plasma's expansion was measured in time and space using spectroscopic techniques. Lineshapes and intensities from various plasma species were used to determine electron and ion densities and temperatures. Electron densities from the mid-10{sup 15} to mid-10{sup 16} cm{sup -3} were generated with corresponding electron temperatures of between 1 and 10eV. These parameters were measured at distances of up to 1.85 cm from the wire surface at times in excess of 1 {micro}s from the initial wire breakdown event. In addition, a hydrocarbon plasma from surface contaminants on the wire was also measured. Control of these contaminants by judicious choice of wire material, size, and/or surface coating allows for the ability to generate plasmas with similar density and temperature to those given above, but with lower atomic masses.

• Research Organization: Sandia National Laboratories
• Sponsoring Organization: USDOE
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 942062
• Report Number(s): SAND2008-6161
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
ELECTRON BEAMS
ELECTRON BEAMS -FOCUSING
ELECTRON TEMPERATURE
FOCUSING
ION TEMPERATURE
PLASMA DENSITY
PLASMA PRODUCTION
Plasma spectroscopy.
Radiography.
X-RAY SOURCES