Knudsen layer formation in laser induced thermal desorption.

Laser induced thermal desorption of Xe atoms into vacuum from a metal surface following the nano-second pulsed laser heating was investigated by the time-of-flight (TOF) measurement. The desorption flow was studied at a wide range of desorption flux by varying the initially prepared Xe coverage Θ (1 ML = 4.5 × 10(18) atoms/m(2)). At Θ = 0.3 ML, the TOF of Xe was well represented by a Maxwell-Boltzmann velocity distribution, which is in good agreement with thermal desorption followed by collision-free flow. At Θ > 0.3 ML, the peak positions of the TOF spectra were shifted towards the smaller values and became constant at large Θ, which were well fitted with a shifted Maxwell-Boltzmann velocity distribution with a temperature TD and a stream velocity u. With TD fixed at 165 K, u was found to increase from 80 to 125 m/s with increasing Θ from 1.2 to 4 ML. At Θ > 4 ML, the value of u becomes constant at 125 m/s. The converging feature of u was found to be consistent with analytical predictions and simulated results based on the Knudsen layer formation theory. We found that the Knudsen layer formation in laser desorption is completed at Knudsen number Kn <0.39.

[1]  M. Asscher,et al.  Photoinduced desorption of Xe from porous Si following ultraviolet irradiation: evidence for a selective and highly effective optical activity. , 2011, Physical review letters.

[2]  K. Fukutani,et al.  Photostimulated desorption of Xe from Au(001) surfaces via transient Xe − formation , 2011, 1206.5398.

[3]  Zhibin Lin,et al.  Selective ablation of Xe from silicon surfaces: molecular dynamics simulations and experimental laser patterning. , 2011, The journal of physical chemistry. A.

[4]  M. Dürr,et al.  Second-harmonic microscopy for fluence-dependent investigation of laser-induced surface reactions , 2011 .

[5]  T. Motohiro,et al.  Considerations on the determining factors of the angular distribution of emitted particles in laser ablation , 2010 .

[6]  Y. Fei,et al.  Classical and quantum diffusion of hydrogen atoms on Cu(1 1 1) , 2009 .

[7]  T. Motohiro,et al.  Angular distribution of atoms ejected by laser ablation of different metals , 2009 .

[8]  B. Davidsson.  Comet Knudsen Layers , 2008 .

[9]  M. Loy,et al.  Quantum diffusion of H on Pt(111): step effects. , 2006, Physical review letters.

[10]  B. Luk’yanchuk,et al.  Imaging of Vapor Plumes Produced by Matrix Assisted Laser Desorption: A Plume Sharpening Effect , 1999 .

[11]  A. Miotello,et al.  Laser-pulse sputtering of aluminum: Vaporization, boiling, superheating, and gas-dynamic effects. , 1994, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

[12]  Mazumder,et al.  Mathematical model for laser ablation to generate nanoscale and submicrometer-size particles. , 1994, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

[13]  H. Urbassek,et al.  Effect of gas‐phase collisions in pulsed‐laser desorption: A three‐dimensional Monte Carlo simulation study , 1993 .

[14]  J. Kools,et al.  A simple formalism for the prediction of angular distributions in laser ablation deposition , 1993 .

[15]  H. Urbassek,et al.  Monte Carlo study of Knudsen layers in evaporation from elemental and binary media , 1993 .

[16]  Kelly.  Gas dynamics of the pulsed emission of a perfect gas with applications to laser sputtering and to nozzle expansion. , 1992, Physical review. A, Atomic, molecular, and optical physics.

[17]  T. S. Baller,et al.  Gas flow dynamics in laser ablation deposition , 1992 .

[18]  Arunava Gupta,et al.  Primary and secondary mechanisms in laser-pulse sputtering , 1992 .

[19]  Urbassek,et al.  Kinetic study of pulsed desorption flows into vacuum. , 1991, Physical review. A, Atomic, molecular, and optical physics.

[20]  Narayan,et al.  Pulsed-laser evaporation technique for deposition of thin films: Physics and theoretical model. , 1990, Physical review. B, Condensed matter.

[21]  R. Kelly.  On the dual role of the Knudsen layer and unsteady, adiabatic expansion in pulse sputtering phenomena , 1990 .

[22]  Roger Kelly,et al.  Reconsidering the mechanisms of laser sputtering with Knudsen-layer formation taken into account , 1988 .

[23]  R. Lucchese,et al.  Anisotropic translational energy distribution due to gas-phase collisions in rapid desorption of molecules from surfaces , 1988 .

[24]  Roger Kelly,et al.  On the effect of Knudsen-layer formation on studies of vaporization, sputtering, and desorption , 1988 .

[25]  Zeiri,et al.  Effects of gas-phase collisions on particles rapidly desorbed from surfaces. , 1987, Physical review. B, Condensed matter.

[26]  R. Lucchese,et al.  Monte-carlo simulations of gas-phase collisions in rapid desorption of molecules from surfaces , 1987 .

[27]  H. Coufal,et al.  Surface-temperature measurement during pulsed laser-induced thermal desorption of xenon from a copper film , 1986 .

[28]  H. Coufal,et al.  Pulsed Laser-Induced Thermal Desorption of Xenon , 1986 .

[29]  R. David,et al.  Dynamical parameters of desorbing molecules , 1985 .

[30]  Cowin.  Comment on "Critical cone in phonon-induced desorption of helium" , 1985, Physical review letters.

[31]  P. Stair,et al.  Pulsed laser induced thermal desorption of CO from copper surfaces , 1983 .

[32]  G. Wedler,et al.  Laser induced thermal desorption of carbon monoxide from Fe(110) surfaces , 1982 .

[33]  P. Taborek.  Critical Cone in Phonon-Induced Desorption of Helium , 1982 .

[34]  Gabor A. Somorjai,et al.  The surface reconstructions of the (100) crystal faces of iridium, platinum and gold. I. Experimental observations and possible structural models , 1981 .

[35]  C. A. Becker,et al.  Measurement of fast desorption kinetics of D2, from tungsten by laser induced thermal desorption , 1978 .

[36]  S. A. Schaaf.  Rarefied Gas Dynamics , 1969 .