Temperature peaking at beginning of breakdown in 2.45 GHz pulsed off-resonance electron cyclotron resonance ion source hydrogen plasma

Journal Article · Mon Oct 15 04:00:00 EDT 2012 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.4757113· OSTI ID:22093780

Cortazar, O. D. ^[1]; Megia-Macias, A.; Vizcaino-de-Julian, A. ^[2]

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1. Universidad de Castilla-La Mancha. E.T.S.I.I., Camilo J. Cela s/n, 13071-C. Real (Spain)
2. E.S.S. Bilbao, Edificio Cosimet, Landabarri 2, 48940-Leioa, Vizcaya (Spain)

An experimental study of temperature and density evolution during breakdown in off-resonance ECR hydrogen plasma is presented. Under square 2.45 GHz microwave excitation pulses with a frequency of 50 Hz and relative high microwave power, unexpected transient temperature peaks that reach 18 eV during 20 {mu}s are reported at very beginning of plasma breakdown. Decays of such peaks reach final stable temperatures of 5 eV at flat top microwave excitation pulse. Evidence of interplay between incoming power and duty cycle giving different kind of plasma parameters evolutions engaged to microwave coupling times is observed. Under relative high power conditions where short microwave coupling times are recorded, high temperature peaks are measured. However, for lower incoming powers and longer coupling times, temperature evolves gradually to a higher final temperature without peaking. On the other hand, the early instant where temperature peaks are observed also suggest a possible connection with preglow processes during breakdown in ECRIS plasmas.

• OSTI ID: 22093780
• Journal Information: Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 10 Vol. 83; ISSN 0034-6748; ISSN RSINAK
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BREAKDOWN
COUPLING
DENSITY
ECR ION SOURCES
ELECTRON CYCLOTRON-RESONANCE
ELECTRON TEMPERATURE
EXCITATION
HIGH-FREQUENCY DISCHARGES
ION TEMPERATURE
MICROWAVE RADIATION
PLASMA
PLASMA DENSITY
PULSES
TRANSIENTS