Multiphoton dissociation of CF3I clusters by IR laser radiation

Ultrafast Dissociation Dynamics of [Fe(CO)5]n Clusters Induced by Femtosecond IR Radiation

“…In the case of [Fe(CO) 5 ] n clusters with ΔE = 0.2 eV, we estimate the evaporation temperature as T ev ≈ 105 K. Comparison of the obtained value of T ev with that of T max shows that, in the case of the excitation by the femtosecond IR radiation, "overheating" of clusters with respect to the value of the evaporation temperature takes place, which, nevertheless, does not lead to any significant deviations from the model mechanism of sequential evaporation of molecules from the cluster. Independent data on variation of the temperature of the cluster can be obtained, for example, from the analysis of the dynamics of variation of the velocity distribution of molecules that are formed as a result of the decay of clusters (see, e.g., previous results 13 ). The use of the linear type time-of-flight mass spectrometer makes it possible to retrieve the distribution over the projection of the velocity of the detected ion onto the axis of the mass spectrometer from the width of the mass peak.…”

“…Particles were detected by the photoionization time-of-flight mass-spectrometry method. The time resolution in these experiments was ∼10 –8 s and 10 –7 s . Results of these experiments made it possible to conclude that all relaxation processes in examined clusters, including their monomolecular decay, occur much faster than within 10 –8 –10 –7 s, and, on this time scale, the IR dissociation is, in fact, a stationary (or close to it) process of sequential evaporation of molecules.…”

“…According to the results of our measurements, the value of P cr for the Fe(CO) 5 + Ar gas mixture, which we used, is P cr ≈ 30 kPa. As for the parameters N cr and a, we chose N cr = 7.5 for the former of them, 12 and, taking into account that the exponent a in our previous investigations with (CF 3 I) n clusters 13 was in the interval 1.7 < a < 2.3, we chose the value of the parameter a to be 2.0. Although such an estimate of the cluster average size is rather rough, we believe that it gives the correct idea about the value of N under our experimental conditions.…”

“…In our previous works, we investigated the IR dissociation of (CF 3 I) n clusters 12,13 and (IF 2 CCOF) n clusters 14 The time resolution in these experiments was ∼10 −8 s 13 and 10 −7 s. 14 Results of these experiments made it possible to conclude that all relaxation processes in examined clusters, including their monomolecular decay, occur much faster than within 10 −8 −10 −7 s, and, on this time scale, the IR dissociation is, in fact, a stationary (or close to it) process of sequential evaporation of molecules. It seems that the dynamics of intracluster processes, including any nonstationary effects, can be observed only upon using picosecond or subpicosecond IR pulses.…”

Disintegration of Ar N , Kr N , and (N2) N clusters during collisions with highly vibrationally excited SF6 molecules

“…The processes of interaction of high energy cluster and ion beams with a surface are of particular interest in this field [13][14][15][16][17][18][19]. Cluster beams are also employed to study the extreme processes induced by the collisions of clusters with a surface [13][14][15], the photodissociation of clusters [20], and intercluster reactions [21][22][23]. The possibil ity of doping clusters by molecules (or atoms) due to the trapping of molecules by clusters from an inter secting molecular beam or during the passage of a cluster beam through a cell with a molecular gas signif icantly widens the filed of application of molecular and cluster beams [24,25].…”