LINEAR ELECTRIC-FIELD MASS ANALYSIS - A TECHNIQUE FOR 3-DIMENSIONAL HIGH MASS RESOLUTION SPACE PLASMA COMPOSITION MEASUREMENTS

被引:18
作者
MCCOMAS, DJ
NORDHOLT, JE
BAME, SJ
BARRACLOUGH, BL
GOSLING, JT
机构
[1] Space Plasma Physics Group, Los Alamos National Laboratory, Los Alamos
关键词
D O I
10.1073/pnas.87.15.5925
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
A revolutionary type of three-dimensional space plasma composition analyzer has been developed that combines very high-resolution mass composition measurements on a fraction of the incident ions simultaneously with lower mass resolution but high sensitivity measurements of the remaining population in a single compact and robust sensor design. Whereas the lower mass resolution measurements are achieved using conventional energy /charge (E/q) and linear time-of-flight analysis, the high mass resolution measurements are made by timing reflected E/q analyzed ions in a linear electric field (LEF). In a LEF the restoring (reflecting) force that an ion experiences in the direction parallel to the field is proportional to the depth it travels into the LEF region, and its equation of motion in that direction is that of a simple harmonic oscillator. Consequently, an ion's travel time is independent of its initial angle and energy and is simply proportional to the square root of the ion's mass/charge (m/q). The measured m/q resolution, (m/q)/Δ(m/q), for a small LEF-based prototype that we have developed and tested is ≈ 20. In addition, our laboratory measurements with the prototype instrument show that characteristic time-of-flight spectra allow the resolution of atomic and molecular species with nearly identical m/q values. The measured response of the prototype is in excellent agreement with computer simulations of the device. Advanced design work using this computer simulation indicates that three-dimensional plasma composition analyzers with m/q resolutions of at least 50 are readily achievable.
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页码:5925 / 5929
页数:5
相关论文
共 14 条
  • [11] THE AMPTE CCE HOT-PLASMA COMPOSITION EXPERIMENT (HPCE)
    SHELLEY, EG
    GHIELMETTI, A
    HERTZBERG, E
    BATTEL, SJ
    ALTWEGGVONBURG, K
    BALSIGER, H
    [J]. IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING, 1985, 23 (03): : 241 - 245
  • [12] THE GIOTTO IMPLANTED ION SPECTROMETER (IIS) PHYSICS AND TECHNIQUE OF DETECTION
    WILKEN, B
    WEISS, W
    STUDEMANN, W
    HASEBE, N
    [J]. JOURNAL OF PHYSICS E-SCIENTIFIC INSTRUMENTS, 1987, 20 (06): : 778 - 785
  • [13] 2-PI-RADIAN FIELD-OF-VIEW TOROIDAL ELECTROSTATIC ANALYZER
    YOUNG, DT
    BAME, SJ
    THOMSEN, MF
    MARTIN, RH
    BURCH, JL
    MARSHALL, JA
    REINHARD, B
    [J]. REVIEW OF SCIENTIFIC INSTRUMENTS, 1988, 59 (05) : 743 - 751
  • [14] YOUNG DT, 1989, GEOPHYS MONOGR SER, V54, P143