کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1682566 | 1010475 | 2009 | 5 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Study of ion emission from a germanium crystal surface under impact of fast Pb ions in channeling conditions
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
سطوح، پوششها و فیلمها
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چکیده انگلیسی
A thin germanium crystal has been irradiated at GANIL by Pb beams of 29 MeV/A (charge state Qin = 56 and 72) and of 5.6 MeV/A (Qin = 28). The induced ion emission from the sample entrance surface was studied, impact per impact, as a function of Qin, velocity vin and energy loss ÎE in the crystal. The Pb ions transmitted through the crystal were analyzed in charge (Qout) and energy using the SPEG spectrometer. The emitted ionized species were detected and analyzed in mass by a time-Of-flight multianode detector (LAG). Channeling was used to select peculiar ÎE values in Ge and hence peculiar Pb ion trajectories close to the emitting entrance surface. The experiment was performed in standard vacuum. No Ge emission was found. The dominating emitted species are H+ and hydrocarbon ions originating from the contamination layer on top of the crystal. The mean value ãMã of the number of detected species per incoming Pb ion (multiplicity) varies as (Qin/vin)p, with p values in agreement with previous results. We have clearly observed an influence of the energy deposition ÎE in Ge on the emission from the top contamination layer. When selecting increasing values of ÎE, we observed a rather slow increase of ãMã. On the contrary, the probabilities of high multiplicity values, which are essentially connected to fragmentation after emission, strongly increase with ÎE.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms - Volume 267, Issue 6, March 2009, Pages 876-880
Journal: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms - Volume 267, Issue 6, March 2009, Pages 876-880
نویسندگان
A. L'Hoir, C. Koumeir, S. Della Negra, P. Boduch, P. Roussel-Chomaz, A. Cassimi, M. Chevallier, C. Cohen, D. Dauvergne, M. Fallavier, D. Jacquet, B. Manil, J.-C. Poizat, C. Ray, H. Rothard, D. Schmaus, M. Toulemonde,