Multielectron dissociative ionization of CH(3)I clusters under moderate intensity ps laser irradiation
Φόρτωση...
Ημερομηνία
Συγγραφείς
Karras, G.
Kosmidis, C.
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
Περίληψη
Τύπος
Είδος δημοσίευσης σε συνέδριο
Είδος περιοδικού
peer reviewed
Είδος εκπαιδευτικού υλικού
Όνομα συνεδρίου
Όνομα περιοδικού
International Journal of Mass Spectrometry
Όνομα βιβλίου
Σειρά βιβλίου
Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
The interaction of 35ps laser pulses with methyl iodide clusters in the intensity region of 10(12)-3 x 10(13) W/cm(2) is studied at lambda = 266,532 and 1064 nm by means of time-of-flight mass spectrometry. At lambda = 532 and 1064 nm the multielectron dissociative ionization (MEDI) of clusters results in highly charged atomic fragment (up to I(7+)) ion production of high kinetic energy. The explosion of the multiple charged cluster ions is found to be isotropic, while an asymmetric charge distribution prior to their fragmentation is observed. Moreover, negative ion formation is observed. The MEDI of clusters exhibits a dependence on laser polarization and the intensity thresholds for the observation of the fragment ions are determined for linear and circular laser polarization. These intensity thresholds are found to be about three orders of magnitude lower than those reported by experiments with 35 ps laser pulses on CH(3)I monomers. For the observed MEDI of (CH(3)I)(n) clusters a mechanism is proposed. According to this mechanism, the clusters are initially single ionized by multiphoton absorption and an internal electric field is created within the cluster, which distorts the potential barriers. This distortion increases the probability for electron tunneling even at relatively low laser intensities, giving thus rise to the formation of negatively charged moieties within the clusters, which prevent the cluster elongation and facile further the tunneling process. This procedure results in a higher distortion of the internal barriers and an increased ionization of the clusters, which, due to increased repulsive forces, finally fragment leading to multiple charged high kinetic energy fragment ion production. (C) 2010 Elsevier B.V. All rights reserved.
Περιγραφή
Λέξεις-κλειδιά
ch3i, cluster, medi, negative ions, methyl-iodide clusters, induced coulomb explosion, charged atomic ions, x-ray-emission, nanosecond laser, multiphoton ionization, assistant generation, multiple-ionization, molecular clusters, mass-spectrometry
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
<Go to ISI>://000275258700010
http://ac.els-cdn.com/S1387380610000084/1-s2.0-S1387380610000084-main.pdf?_tid=5b4c2d21ddfaeadb0dca3738fe8a6c57&acdnat=1334228903_47a11baab42e1496cf239154ac84ee1e
http://ac.els-cdn.com/S1387380610000084/1-s2.0-S1387380610000084-main.pdf?_tid=5b4c2d21ddfaeadb0dca3738fe8a6c57&acdnat=1334228903_47a11baab42e1496cf239154ac84ee1e
Γλώσσα
en
Εκδίδον τμήμα/τομέας
Όνομα επιβλέποντος
Εξεταστική επιτροπή
Γενική Περιγραφή / Σχόλια
Ίδρυμα και Σχολή/Τμήμα του υποβάλλοντος
Πανεπιστήμιο Ιωαννίνων. Σχολή Επιστημών και Τεχνολογιών. Τμήμα Βιολογικών Εφαρμογών και Τεχνολογιών