Experimental measurements are reported for the Penning ionization of an argon target by impact of metastable helium atoms. The energy spectra of the ejected electrons are obtained at a series of angles in the range 30° to 90°, and the intensities due to the different metastable states compared

2014 Les auteurs ont étudié le spectre en énergie des électrons éjectés au cours de l'ionisation Penning de l'azote moléculaire par les métastables de l'hélium. Un modèle, faisant intervenir la formation d'une quasimolécule, est proposé pour rendre compte de certaines anomalies dans l'ionisation Penning par l'état métastable 2 3S. Les auteurs suggèrent également la présence d'un état autoionisant de N2 qui aurait pour effet d'accroître la section efficace d'ionisation par l'état métastable 2 1S. Abstract. 2014 A study is reported of the ejected electron spectra resulting from Penning ionization of a molecular nitrogen target by impact of helium metastables. A model is proposed for ionization by the 2 3S metastable in which the formation of a quasi-molecular complex is invoked, and it is suggested that the presence of an autoionizing state of N2 leads to enhancement of certain cross sections for ionization by the 2 1S metastable.

No abstract

Penning ionization of the H a molecule by the He'(2'S) metastable atom is studied. The energy shift is measured for the three observed X, A and B eiectronic bands of the residual HzO' ion. The absence of the vibrational structures is discussed in light of the known interaction potential surface of the He'-t120 complex. More altention is given to the X electronic band characterized by interference structures at high electron energy and an important angular dependence intensity.

No abstract