skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Lifetime of anode polymer in magnetically insulated ion diodes for high-intensity pulsed ion beam generation

Abstract

Generation of high-intensity pulsed ion beam (HIPIB) has been studied experimentally using polyethylene as the anode polymer in magnetically insulated ion diodes (MIDs) with an external magnetic field. The HIPIB is extracted from the anode plasma produced during the surface discharging process on polyethylene under the electrical and magnetic fields in MIDs, i.e., high-voltage surface breakdown (flashover) with bombardments by electrons. The surface morphology and the microstructure of the anode polymer are characterized using scanning electron microscopy and differential scanning calorimetry, respectively. The surface roughening of the anode polymer results from the explosive release of trapped gases or newly formed gases under the high-voltage discharging, leaving fractured surfaces with bubble formation. The polyethylene in the surface layer degrades into low-molecular-weight polymers such as polyethylene wax and paraffin under the discharging process. Both the surface roughness and the fraction of low molecular polymers apparently increase as the discharging times are prolonged for multipulse HIPIB generation. The changes in the surface morphology and the composition of anode polymer lead to a noticeable decrease in the output of ion beam intensity, i.e., ion current density and diode voltage, accompanied with an increase in instability of the parameters with the prolonged discharge times. Themore » diode voltage (or surface breakdown voltage of polymer) mainly depends on the surface morphology (or roughness) of anode polymers, and the ion current density on the composition of anode polymers, which account for the two stages of anode polymer degradation observed experimentally, i.e., stage I which has a steady decrease of the two parameters and stage II which shows a slow decrease, but with an enhanced fluctuation of the two parameters with increasing pulses of HIPIB generation.« less

Authors:
; ; ; ;  [1]
  1. Surface Engineering Laboratory, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China)
Publication Date:
OSTI Identifier:
20953252
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 78; Journal Issue: 2; Other Information: DOI: 10.1063/1.2437760; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ANODES; CURRENT DENSITY; ELECTRIC POTENTIAL; FLASHOVER; GASES; ION BEAMS; IONS; MAGNETIC FIELDS; MORPHOLOGY; PARAFFIN; POLYETHYLENES; ROUGHNESS; SCANNING ELECTRON MICROSCOPY; SURFACES; THERMIONIC DIODES

Citation Formats

Zhu, X. P., Dong, Z. H., Han, X. G., Xin, J. P., and Lei, M. K. Lifetime of anode polymer in magnetically insulated ion diodes for high-intensity pulsed ion beam generation. United States: N. p., 2007. Web. doi:10.1063/1.2437760.
Zhu, X. P., Dong, Z. H., Han, X. G., Xin, J. P., & Lei, M. K. Lifetime of anode polymer in magnetically insulated ion diodes for high-intensity pulsed ion beam generation. United States. doi:10.1063/1.2437760.
Zhu, X. P., Dong, Z. H., Han, X. G., Xin, J. P., and Lei, M. K. Thu . "Lifetime of anode polymer in magnetically insulated ion diodes for high-intensity pulsed ion beam generation". United States. doi:10.1063/1.2437760.
@article{osti_20953252,
title = {Lifetime of anode polymer in magnetically insulated ion diodes for high-intensity pulsed ion beam generation},
author = {Zhu, X. P. and Dong, Z. H. and Han, X. G. and Xin, J. P. and Lei, M. K.},
abstractNote = {Generation of high-intensity pulsed ion beam (HIPIB) has been studied experimentally using polyethylene as the anode polymer in magnetically insulated ion diodes (MIDs) with an external magnetic field. The HIPIB is extracted from the anode plasma produced during the surface discharging process on polyethylene under the electrical and magnetic fields in MIDs, i.e., high-voltage surface breakdown (flashover) with bombardments by electrons. The surface morphology and the microstructure of the anode polymer are characterized using scanning electron microscopy and differential scanning calorimetry, respectively. The surface roughening of the anode polymer results from the explosive release of trapped gases or newly formed gases under the high-voltage discharging, leaving fractured surfaces with bubble formation. The polyethylene in the surface layer degrades into low-molecular-weight polymers such as polyethylene wax and paraffin under the discharging process. Both the surface roughness and the fraction of low molecular polymers apparently increase as the discharging times are prolonged for multipulse HIPIB generation. The changes in the surface morphology and the composition of anode polymer lead to a noticeable decrease in the output of ion beam intensity, i.e., ion current density and diode voltage, accompanied with an increase in instability of the parameters with the prolonged discharge times. The diode voltage (or surface breakdown voltage of polymer) mainly depends on the surface morphology (or roughness) of anode polymers, and the ion current density on the composition of anode polymers, which account for the two stages of anode polymer degradation observed experimentally, i.e., stage I which has a steady decrease of the two parameters and stage II which shows a slow decrease, but with an enhanced fluctuation of the two parameters with increasing pulses of HIPIB generation.},
doi = {10.1063/1.2437760},
journal = {Review of Scientific Instruments},
number = 2,
volume = 78,
place = {United States},
year = {Thu Feb 15 00:00:00 EST 2007},
month = {Thu Feb 15 00:00:00 EST 2007}
}