月の大気中の実質的なナトリウム源として,光子刺激による脱吸収
1Department of Physics and Astronomy, Rutgers, The State University of New Jersey, Piscataway 08854-8019, USA.
Nature
|August 24, 1999
まとめ
光子刺激による脱吸収は,月面からナトリウム原子を効率的に放出します. 紫外線によって誘発されるこのプロセスは,月の薄い大気の重要な源であり,熱吸収は水星にとっても重要です.
科学分野:
- 惑星科学 惑星科学
- 大気化学 大気化学
- 表面物理学 表面物理学について
背景:
- 水星と月は,原子のナトリウムとカリウムを含む薄い大気を持っています.
- これらの要素は,短い保持時間 (時間) のために継続的な補給を必要とします.
- 提案されている補給メカニズムには,スプッタリング,インパクト,熱分解,光子刺激による分解が含まれるが,支配的なプロセスは不明である.
研究 の 目的:
- シミュレートされた月のシリケート表面からのナトリウムの光子刺激による脱吸収を調査する.
- 紫外線光子によって誘発されるナトリウム原子の放出の効率とメカニズムを決定する.
- 月と水星の大気に対する光子刺激による脱吸収の寄与を評価する.
主な方法:
- 月面の条件をシミュレートする実験室での実験.
- シリケート表面を紫外線光子 (波長<300 nm) で約250 Kで爆撃する.
- 電子刺激によって誘発されたナトリウム原子脱吸収の分析.
主要な成果:
- シミュレートされた月の表面からのナトリウムの光子刺激による脱吸収は,非常に効率的です.
- 脱吸収は主に電子刺激によって引き起こされ,熱プロセスや運動量移転によって引き起こされない.
- 紫外線光子の太陽流は,月の大気中のナトリウムに大きく貢献するのに十分である.
結論:
- フォトン刺激による脱吸収は,月の大気にナトリウムを供給する重要なプロセスです.
- 水星では,光子刺激による熱吸収と熱吸収の両方が大気中のナトリウムにとって重要である可能性が高い.
- この地表と大気の相互作用を理解することは,惑星科学にとって極めて重要です.
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