Collisional quenching of metastable states of antiprotonic helium by hydrogen and deuterium molecules
Collisional quenching of metastable states of antiprotonic helium by hydrogen and deuterium molecules
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氢和氘分子对反质子氦亚稳态的碰撞猝灭
DOI：
10.1007/s100530170246
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
D. Horvath
中科院分区：
文献类型：
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作者：
B. Ketzer;T. von Egidy;F. Hartmann;C. Maierl;R. Pohl;J. Eades;E. Widmann;T. Yamazaki;M. Kumakura;N. Morita;R. Hayano;M. Hori;T. Ishikawa;H. Torii;I. Sugai;D. Horvath
研究了反质子氦在与氢和氘分子碰撞时的亚稳态猝灭。系统地研究了在ppm水平下不同h2o2和d2混合比下的延迟湮灭时间谱，揭示了它们形状的特征变化，这表明在这两种情况下，能级猝灭都有很强的主和轨道量子数依赖。应用激光光谱技术测量单个态和级联的寿命，我们推导出态(n,l)=(39,35)和（37,34）的h2和d2淬火截面。这些横截面证实了d2分子的猝灭效率随着先前关于h2ad混合物的研究中状态主量子数的增加而显著增加。我们的实验表明，低nstate（37,34）受d2的影响比H2小，而高nstate（39,35）同样被两种同位素淬灭。
The quenching of metastable states of antiprotonic helium by collisions with hydrogen and deuterium molecules was studied. A systematic investigation of the delayed annihilation time spectra at various H2and D2admixture ratios at the ppm level revealed characteristic changes of their shape, which indicated a strong principal and orbital quantum number dependent quenching of levels in both cases. Applying a laser spectroscopy technique to measure the lifetimes of individual states and cascades we deduced H2and D2quenching cross-sections for the states (n,l)= (39, 35) and (37, 34). These cross-sections establish for D2molecules the strong increase of the quenching efficiency with increasing principal quantum numbernof the state under investigation previously reported for the case of H2admixtures. Our experiments indicate that the low-nstate (37, 34) is somewhat less affected by D2than by H2, while the high-nstate (39, 35) is equally quenched by both isotopes.