Potential sputtering of ionic species from rare gas solids by multiply charged ion impact

Abstract

Abstract. The interaction of low-energy multiply charged Ar q+ (q ≤ 7) ions with a solid Ne surface is experimentally studied. Desorption of very large cluster ions Ne + n (n > 100) is observed. The size distribution of smaller (n = 1 ∼ 3) cluster ions depends strongly on the charge state of the incident ion, whereas that of larger (n > 7) cluster ions exhibits no dependence on the charge state, indicating that desorption of large cluster ions is due to kinetic sputtering. The potential sputtering yield is estimated by analyzing the size distribution of the desorbed cluster ions. The results suggest that the ion desorption mechanism, which is known as desorption induced by electronic transitions, can also be applied to the present results.

Desorption of cluster ions from solid Ne by low-energy ion impact

“…The time that it takes for the desorbed ions to reach the detector is a few microseconds, and the desorbed cluster ions may undergo structural rearrangement and fragmentation within the time [25]. Although the largest observable cluster size (n = 20) is limited in the experiment described herein by the range of used in the present QMS (M max = 400 amu), the Ne + n ions up to a size of n > 100 were measured in our previous experiments using a time-of-flight technique [23]. The cluster ion signal intensity decreases exponentially with cluster size, but the existence of a discontinuity in the signal intensity at size n=14 to 15 is confirmed (see Fig.…”

“…Details of the experimental apparatus have been published elsewhere [23,24]. Briefly, the experiments were carried out in a UHV chamber with a base pressure of 8 × 10 −9 Pa and equipped with a closed-cycle helium cryostat.…”

Temperature effect of metastable atom desorption from solid Ne by low-energy electron impact

“…We will discuss the results within the framework of the CE mechanism, and we also performed a simple trajectory calculation of desorbed excited Ne atoms. Figure 1 shows a side view of the experimental setup, which was similar to the one we used in our previous work [3][4][5], except for the addition of a low-energy electron gun and a channel electron multiplier (CEM) for the detection of desorbed metastable atoms. The main chamber was evacuated by a series of turbo molecular pumps and a Ti-getter pump, resulting in a pressure of approximately 3·10 -8 Pa.…”