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Title: Observation and particle simulation of vaporized W, Mo, and Be in PISCES-B plasma for vapor-shielding studies

Authors:
; ; ; ; ; ; ;
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1346261
Grant/Contract Number:
FG02-07ER54912
Resource Type:
Journal Article: Published Article
Journal Name:
Nuclear Materials and Energy
Additional Journal Information:
Journal Volume: 12; Journal Issue: C; Related Information: CHORUS Timestamp: 2017-10-23 13:45:00; Journal ID: ISSN 2352-1791
Publisher:
Elsevier
Country of Publication:
Netherlands
Language:
English

Citation Formats

Ibano, K., Nishijima, D., Yu, J. H., Baldwin, M. J., Doerner, R. P., Takizuka, T., Lee, H. T., and Ueda, Y.. Observation and particle simulation of vaporized W, Mo, and Be in PISCES-B plasma for vapor-shielding studies. Netherlands: N. p., 2017. Web. doi:10.1016/j.nme.2017.01.016.
Ibano, K., Nishijima, D., Yu, J. H., Baldwin, M. J., Doerner, R. P., Takizuka, T., Lee, H. T., & Ueda, Y.. Observation and particle simulation of vaporized W, Mo, and Be in PISCES-B plasma for vapor-shielding studies. Netherlands. doi:10.1016/j.nme.2017.01.016.
Ibano, K., Nishijima, D., Yu, J. H., Baldwin, M. J., Doerner, R. P., Takizuka, T., Lee, H. T., and Ueda, Y.. 2017. "Observation and particle simulation of vaporized W, Mo, and Be in PISCES-B plasma for vapor-shielding studies". Netherlands. doi:10.1016/j.nme.2017.01.016.
@article{osti_1346261,
title = {Observation and particle simulation of vaporized W, Mo, and Be in PISCES-B plasma for vapor-shielding studies},
author = {Ibano, K. and Nishijima, D. and Yu, J. H. and Baldwin, M. J. and Doerner, R. P. and Takizuka, T. and Lee, H. T. and Ueda, Y.},
abstractNote = {},
doi = {10.1016/j.nme.2017.01.016},
journal = {Nuclear Materials and Energy},
number = C,
volume = 12,
place = {Netherlands},
year = 2017,
month = 8
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1016/j.nme.2017.01.016

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  • We report the results of two-dimensional particle simulations (computer experiments) of finite plasma expansion between biased plane parallel electrodes. We show that the simulation produces results consistent with the existing one-dimensional analytical model. While the plasma expansion on the low-potential side is space-charge limited, on the opposite side it is due to ambipolar diffusion. The time-dependent simulated ion current to the electrode exhibits a modulation which has not been experimentally observed. This is identified to be a consequence of the oscillation in sheath front ion density which occurs because of the ion acoustic waves generated during the expansion. This modulation,more » which is greater at lower ion temperatures and nonuniform with respect to the electrode surface, can be used to estimate the transient number density in the plasma. Modifications to conventional experimental detection circuits which could help in the detection of these waves are presented. {copyright} {ital 1997 American Institute of Physics.}« less
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  • The chemical erosion behavior of graphite materials preexposed in the Tokamak Fusion Test Reactor (TFTR) as the bumper limiter has been investigated spectroscopically under deuterium plasma bombardment in the Plasma Interactive Surface Component Experimental Station-A (PISCES-A) facility. The deuterium plasma bombardment conditions are ion bombarding energy of 300 eV, ion flux of 1.7{times}10{sup 18} ions s{sup {minus}1} cm{sup {minus}2}, plasma density of 1.4{times}10{sup 12} cm{sup {minus}3}, electron temperature of 11 eV, and neutral pressure of 3{times}10{sup {minus}4} Torr. The chemical erosion yield is measured with calibrated CD-band spectroscopy during the temperaure ramp from 100 to 900 {degree}C at an averagemore » rate of {similar to}5 K/s. The materials used include virgin POCO graphite and graphite tile pieces from the redeposited and eroded areas of the bumper limiter of TFTR. The deuterocarbon formation rate from TFTR redeposits maximizes at {similar to}500 {degree}C. Essentially the same chemical erosion behavior is observed for TFTR-eroded and virgin graphites and is characterized by the compound peak, indicative of two erosion yield maxima at around 575 and 700 {degree}C. The maximum erosion yield for TFTR redeposits is found to be {similar to}15% higher than those of TFTR-eroded and virgin POCO graphites which is attributed to deuterium incorporated in the redeposited material. In addition, the removal behavior of redeposits by helium plasma bombardment has been studied. The removal rate is evaluated to be similar to the physical sputtering yield of carbon by helium. The surface morphology and surface composition have been analyzed with scanning electron microscopy and electron microprobe analysis along with these erosion yield measurements.« less
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