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Title: Production of neutrals and their and effects on the ion chargestates in cathodic vacuum arc plasmas

Abstract

Cathodic arc plasmas are considered fully ionized and theycontain multiply charged ions, yet, gaseous and metal neutrals can bepresent. It is shown that they can cause a significant reduction of theion charge states as measured far from the cathode spots. Several cathodematerials were used to study the evolution the mean ion charge state as afunction of time after arc ignition. The type of cathode material, arccurrent amplitude, intentionally increased background gas, additionalsurfaces placed near the plasma flow, and other factors influence thedegree of charge state reduction because all of these factors influencethe density of neutrals. In all cases, it was found that the mean ioncharge state follows an exponential decay of first order, Q(t) = A *exp(t/tau) + Qss, where A is a parameter describing the importance of thedecay, tau is the characteristic decay time, and Qss is a steady-statevalue approached for continuous arc operation. The extrapolated valuesQ(t-->0) indicate surprisingly high mean charge states as produced atcathode spots and not "skewed" by charge exchange collisions withneutrals.

Authors:
; ;
Publication Date:
Research Org.:
Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
Sponsoring Org.:
USDOE. Administrator for National Nuclear SecurityAdministration Nonproliferation and National Security ProgramDirection
OSTI Identifier:
926618
Report Number(s):
LBNL-63444
R&D Project: Z2N196; BnR: NN4101010
DOE Contract Number:  
DE-AC02-05CH11231
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 102; Related Information: Journal Publication Date: 08/15/2007
Country of Publication:
United States
Language:
English
Subject:
70; cathodic arcs neutrals ion charge states

Citation Formats

Anders, Andre, Oks, Efim M., and Yushkov, Georgy Yu. Production of neutrals and their and effects on the ion chargestates in cathodic vacuum arc plasmas. United States: N. p., 2007. Web. doi:10.1063/1.2769789.
Anders, Andre, Oks, Efim M., & Yushkov, Georgy Yu. Production of neutrals and their and effects on the ion chargestates in cathodic vacuum arc plasmas. United States. doi:10.1063/1.2769789.
Anders, Andre, Oks, Efim M., and Yushkov, Georgy Yu. Wed . "Production of neutrals and their and effects on the ion chargestates in cathodic vacuum arc plasmas". United States. doi:10.1063/1.2769789. https://www.osti.gov/servlets/purl/926618.
@article{osti_926618,
title = {Production of neutrals and their and effects on the ion chargestates in cathodic vacuum arc plasmas},
author = {Anders, Andre and Oks, Efim M. and Yushkov, Georgy Yu.},
abstractNote = {Cathodic arc plasmas are considered fully ionized and theycontain multiply charged ions, yet, gaseous and metal neutrals can bepresent. It is shown that they can cause a significant reduction of theion charge states as measured far from the cathode spots. Several cathodematerials were used to study the evolution the mean ion charge state as afunction of time after arc ignition. The type of cathode material, arccurrent amplitude, intentionally increased background gas, additionalsurfaces placed near the plasma flow, and other factors influence thedegree of charge state reduction because all of these factors influencethe density of neutrals. In all cases, it was found that the mean ioncharge state follows an exponential decay of first order, Q(t) = A *exp(t/tau) + Qss, where A is a parameter describing the importance of thedecay, tau is the characteristic decay time, and Qss is a steady-statevalue approached for continuous arc operation. The extrapolated valuesQ(t-->0) indicate surprisingly high mean charge states as produced atcathode spots and not "skewed" by charge exchange collisions withneutrals.},
doi = {10.1063/1.2769789},
journal = {Journal of Applied Physics},
number = ,
volume = 102,
place = {United States},
year = {Wed May 23 00:00:00 EDT 2007},
month = {Wed May 23 00:00:00 EDT 2007}
}