Photodissociation of water in rare gas matrices: Cage effect and local heating of the lattice

1993 ◽  
Vol 98 (10) ◽  
pp. 7786-7791 ◽  
Author(s):  
E. I. Tarasova ◽  
A. M. Ratner ◽  
V. M. Stepanenko ◽  
I. Ya. Fugol ◽  
M. Chergui ◽  
...  
Keyword(s):  
Local Heating ◽  
Rare Gas ◽  
Cage Effect

Cage effect on the photodissociation of small molecules in rare gas matrices

1992 ◽  
Author(s):  
H. Kunz ◽  
R. Schriever ◽  
M. Chergui ◽  
J. G. McCaffrey ◽  
N. Schwentner
Keyword(s):  
Small Molecules ◽  
Rare Gas ◽  
Cage Effect

Water Photolysis in Rare Gas Environment: The CASPT2 Excited State H2O(A)-Ar Potential

1998 ◽  
Vol 63 (9) ◽  
pp. 1321-1328 ◽  
Author(s):  
Dana Nachtigallová ◽  
Petr Slavíček ◽  
Petr Nachtigall ◽  
Pavel Jungwirth
Keyword(s):  
Excited State ◽  
Degrees Of Freedom ◽  
Energy Surface ◽  
Initial Step ◽  
Rare Gas ◽  
Cage Effect ◽  
Water Photolysis ◽  
First Excited State ◽  
Dynamical Simulations ◽  
And Control

The potential energy surface of the first excited state of the water-argon complex is explored at a multireference perturbation theory level as an initial step of the project aimed at the study and control of photodissociation in H2O-Arn (n = 1, 2, ..., 12) clusters. Ab initio calculations, which will serve as a basis for the construction of an analytical force field for dynamical simulations, reveal the anisotropy of the excited state surface and weak potential coupling between intermolecular and intramolecular degrees of freedom. The importance of the "cage effect" is demonstrated.

UHV-TEM studies of laser-induced damage

1991 ◽  
Vol 49 ◽  
pp. 632-633
Author(s):  
T.S. Savage ◽  
R. Ai ◽  
D. Dunn ◽  
L.D. Marks
Keyword(s):  
Surface Science ◽  
Rapid Heating ◽  
Local Heating ◽  
Routine Practice ◽  
Transmission Electron ◽  
Northwestern University ◽  
Laser Induced Damage ◽  
Set Up ◽  
Focusing Lens ◽  
Diffusion Of Impurities

The use of lasers for surface annealing, heating and/or damage has become a routine practice in the study of materials. Lasers have been closely looked at as an annealing technique for silicon and other semiconductors. They allow for local heating from a beam which can be focused and tuned to different wavelengths for specific tasks. Pulsed dye lasers allow for short, quick bursts which can allow the sample to be rapidly heated and quenched. This short, rapid heating period may be important for cases where diffusion of impurities or dopants may not be desirable.At Northwestern University, a Candela SLL - 250 pulsed dye laser, with a maximum power of 1 Joule/pulse over 350 - 400 nanoseconds, has been set up in conjunction with a Hitachi UHV-H9000 transmission electron microscope. The laser beam is introduced into the surface science chamber through a series of mirrors, a focusing lens and a six inch quartz window.

Point-Cathode Electron Gun Using Electron-Beam Bombardment for Cathode Tip Heating

1990 ◽  
Vol 48 (1) ◽  
pp. 198-199
Author(s):  
Ryo Iiyoshi ◽  
Susumu Maruse ◽  
Hideo Takematsu
Keyword(s):  
Electron Beam ◽  
Tungsten Wire ◽  
Local Heating ◽  
Electron Gun ◽  
Original Position ◽  
Beam Power ◽  
Radius Of Curvature ◽  
High Brightness ◽  
Beam Focusing ◽  
Time Operation

Point cathode electron gun with high brightness and long cathode life has been developed. In this gun, a straightened tungsten wire is used as the point cathode, and the tip is locally heated to higher temperatures by electron beam bombardment. The high brightness operation and some findings on the local heating are presented.Gun construction is shown in Fig.l. Small heater assembly (annular electron gun: 5 keV, 1 mA) is set inside the Wehnelt electrode. The heater provides a disk-shaped bombarding electron beam focusing onto the cathode tip. The cathode is the tungsten wire of 0.1 mm in diameter. The tip temperature is raised to the melting point (3,650 K) at the beam power of 5 W, without any serious problem of secondary electrons for the gun operation. Figure 2 shows the cathode after a long time operation at high temperatures, or high brightnesses. Evaporation occurs at the tip, and the tip part retains a conical shape. The cathode can be used for a long period of time. The tip apex keeps the radius of curvature of 0.4 μm at 3,000 K and 0.3 μm at 3,200 K. The gun provides the stable beam up to the brightness of 6.4×106 A/cm2sr (3,150 K) at the accelerating voltage of 50 kV. At 3.4×l06 A/cm2sr (3,040 K), the tip recedes at a slow rate (26 μm/h), so that the effect can be offset by adjusting the Wehnelt bias voltage. The tip temperature is decreased as the tip moves out from the original position, but it can be kept at constant by increasing the bombarding beam power. This way of operation is possible for 10 h. A stepwise movement of the cathode is enough for the subsequent operation. Higher brightness operations with the rapid receding rates of the tip may be improved by a continuous movement of the wire cathode during the operations. Figure 3 shows the relation between the beam brightness, the tip receding rate by evaporation (αis the half-angle of the tip cone), and the cathode life per unit length, as a function of the cathode temperature. The working life of the point cathode is greatly improved by the local heating.

Long-Term Correlations In Diffusive Motion Of Water Molecules And Rare Gas Atoms In Helium And Argon Aqueous Solutions

2015 ◽  
Vol 60 (8) ◽  
pp. 757-763 ◽  
Author(s):  
V.P. Voloshin ◽  
◽  
G.G. Malenkov ◽  
Yu.I. Naberukhin ◽  
◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Rare Gas ◽  
Water Molecules ◽  
Diffusive Motion ◽  
Rare Gas Atoms

Nitrogen Atom Densities in Rare Gas Diluted N2 Plasmas with Capacitive and Inductive Coupling

2008 ◽  
Vol 128 (10) ◽  
pp. 615-618 ◽  
Author(s):  
Takeshi Kitajima ◽  
Akihiro Kubota ◽  
Toshiki Nakano
Keyword(s):  
Nitrogen Atom ◽  
Inductive Coupling ◽  
Rare Gas

Effect of Excited Particles on Electron Production in Rare Gas RF Breakdown

2010 ◽  
Vol 130 (12) ◽  
pp. 1073-1080
Author(s):  
Norihiko Sasaki ◽  
Mitsuharu Nogaku ◽  
Yutaka Uchida
Keyword(s):  
Rare Gas ◽  
Electron Production ◽  
Rf Breakdown
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