Effects of a transverse-magnetic field on a laser-ablation-assisted-plasma-discharge ion source
- Univ. of Michigan, Ann Arbor, MI (United States)
Experiments have been carried out to study the effects of a transverse-magnetic field on laser-ablation-assisted-plasma-discharges (LAAPD) of aluminum metal in vacuum. The ablated matter is generated by focusing a KrF excimer laser (248 nm, 40 ns, {le} 0.4 J) on a solid aluminum target with a fluence of 4 J/cm{sup 2}. An annular copper ring forms the high voltage discharge electrode, while the target is grounded. Peak plasma discharge voltages of 1--4 kV and peak plasma currents of 0.2--1 kA have been used which result in a peak plasma discharge power of 0.1--1 MW in a 6 {mu}s pulse. Gated emission spectroscopy of 3 kV, 760 A discharges without magnetic field shows observable emission dominated by transitions from Al{sup 2+} ions indicating nearly complete ionization of the ablation plume. Applying a 620 G transverse magnetic field (at 3 kV, 760 A) shows a decrease in Al{sup 2+} emission suggesting that higher ionization states are being populated which have short-wavelength UV emission. LAAPD at a lower voltage of 1.2 kV and 280 A show no Al{sup 2+} emission without the magnetic field; with magnetic field introduced, the Al{sup 2+} emission reappears due to increased electron confinement. This introduction of the transverse magnetic field thus allows the use of lower voltages to produce equivalent numbers of Al{sup 2+} ions than possible without the B-field. Spectroscopic measurements indicate electronic Al{sup 2+} temperatures of about 3 eV in the source plasma.
- OSTI ID:
- 46167
- Report Number(s):
- CONF-940604-; ISBN 0-7803-2006-9; TRN: 95:011226
- Resource Relation:
- Conference: 1994 Institute of Electrical and Electronic Engineers (IEEE) international conference on plasma science, Santa Fe, NM (United States), 6-8 Jun 1994; Other Information: PBD: 1994; Related Information: Is Part Of IEEE conference record -- Abstracts; PB: 252 p.
- Country of Publication:
- United States
- Language:
- English
Similar Records
Volume H/sup -/ generation with the SITEX source in the VITEX reflex mode without cesium
Electric discharge enhancement of laser produced plasma for thin film deposition