TY - JOUR
T1 - Dual IR laser shattering of a water microdroplet
AU - Sugiyama, Akinori
AU - Nakajima, Atsushi
N1 - Funding Information:
This work is partly supported by an XFEL Usage Promotion Project of the Ministry of Education, Culture, Sports, Science, and Technology (MEXT) and by a MEXT-supported Program for the Strategic Research Foundation at Private Universities, 2009–2013. The authors are grateful to Dr. S. Nagaoka for his initial contribution and also to Professors F. Mafuné and J. Kohno for the instrumentation, and A.S. expresses his gratitude for a research fellowship from the Japan Society for the Promotion of Science for Young Scientists.
PY - 2012/10
Y1 - 2012/10
N2 - Ion desorption from the infrared (IR) laser shattering of water microdroplets (ø90 μm in diameter) was experimentally examined by ion current measurements coupled with time-resolved imaging by a charge-coupled-device camera. When a microdroplet was shattered by simultaneous illumination by two IR lasers (λ=2.9 μm) from both the left- and right-hand sides, the time-resolved imaging shows that a lot of small fragments of splash spread around the droplet. The spatial distributions of the small fragments were symmetrically compressed. The resulting fragment swarm was effectively introduced into a vacuum chamber through an inlet skimmer ø0.3-0.4 mm in diameter. The ion current measured from a 10 -6 mol/m 3 NaCl water solution microdroplet using two lasers was considerably enhanced compared to that by single IR laser shattering. When one of the two IR lasers was delayed by 0-1000 μs, the ion current gradually decreased with the delay time, and dropped substantially at delays longer than 100 ns. The results are ascribed to dynamical processes following the multi-photon excitation. The dual IR laser ablation of a liquid droplet can enhance the efficiency of ion formation with a lower dispersion velocity, which can be conveniently combined with time-of-flight mass spectrometry.
AB - Ion desorption from the infrared (IR) laser shattering of water microdroplets (ø90 μm in diameter) was experimentally examined by ion current measurements coupled with time-resolved imaging by a charge-coupled-device camera. When a microdroplet was shattered by simultaneous illumination by two IR lasers (λ=2.9 μm) from both the left- and right-hand sides, the time-resolved imaging shows that a lot of small fragments of splash spread around the droplet. The spatial distributions of the small fragments were symmetrically compressed. The resulting fragment swarm was effectively introduced into a vacuum chamber through an inlet skimmer ø0.3-0.4 mm in diameter. The ion current measured from a 10 -6 mol/m 3 NaCl water solution microdroplet using two lasers was considerably enhanced compared to that by single IR laser shattering. When one of the two IR lasers was delayed by 0-1000 μs, the ion current gradually decreased with the delay time, and dropped substantially at delays longer than 100 ns. The results are ascribed to dynamical processes following the multi-photon excitation. The dual IR laser ablation of a liquid droplet can enhance the efficiency of ion formation with a lower dispersion velocity, which can be conveniently combined with time-of-flight mass spectrometry.
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U2 - 10.1007/s00339-012-7086-0
DO - 10.1007/s00339-012-7086-0
M3 - Article
AN - SCOPUS:84866733191
VL - 109
SP - 31
EP - 37
JO - Applied Physics A: Materials Science and Processing
JF - Applied Physics A: Materials Science and Processing
SN - 0947-8396
IS - 1
ER -