X線パルスがアット秒境界に近づいている.
M Drescher1, M Hentschel, R Kienberger
1Institut für Photonik, Technische Universität Wien, Gusshausstr. 27, A-1040 Wien, Austria.
まとめ
研究者らは,高級ハーモニック生成を用いて単一の柔らかいX線パルスを生成した. レーザーサイクルの長さよりも短いこの超短波パルスにより,原子力学を研究するために,サブフェムト秒解像度を可能にします.
科学分野:
- 量子光学とは,量子光学である.
- アットセカンド・サイエンス
- X線物理学のX線物理学
背景:
- 高度ハーモニック生成 (HHG) は,超短極紫外線 (XUV) と柔らかいX線パルスを生成するための重要なプロセスです.
- 超短のX線パルスを特徴付けるには,フェムト秒未満の解像度を持つ技術が必要で,自然時間スケールでの現象を観察できます.
研究 の 目的:
- ドライビングレーザーの光学サイクルより短い持続時間を持つ孤立した柔らかいX線パルスを生成し,特徴づけます.
- X線パルスのサブフェムト秒解像度測定のための技術を開発する.
主な方法:
- 柔らかいX線パルス (90 eV) は,7フェムト秒 (fs) のレーザーパルス (770 nm) を使用してHHGを通じて生成されました.
- クリプトンの光電子スペクトル検査は,ドライバレーザーの存在で行われた.
- 光電子は,スペクトル拡大を抑制するために,レーザー極化に垂直に検出されました.
- 交差相関測定は,X線パルス持続時間を決定するために使用されました.
主要な成果:
- 1.8 fsの持続時間を持つ孤立した柔らかいX線パルスを測定しました.
- 測定されたX線パルス持続時間は,ドライビングレーザーの振動サイクル (2.6 fs) よりも短い.
- 交差相関測定ではサブレーザーサイクルの解像度が達成されました.
結論:
- 開発された技術は,フェムト秒未満のX線パルスの生成と特徴付けを可能にします.
- この進歩は,実験的なアットセカンド科学の道を開く.
- この研究は,アット秒のスケールで原子や分子過程を観察する可能性を広げています.
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