Plasma channel

Fig. 6.4. Statistical confidence level associated with the electric events synchronized with the laser pulses during a thunderstorm. The color scale is transparent below 98% (i.e., for error risks above 2%), leaving the topographical background uncovered. Arrowhead location of the laser-induced plasma channel Arrow tail laser emitter. Topographic background courtesy of US Geological Survey [31]...

Optical guiding in preformed plasmas has been extensively investigated in experiments mainly oriented to demonstrate the production of relativistic electrons in LWF-related schemes. Plasma channel formation has been pursued with a variety of means, ranging from the use of hydrodynamic and shock-wave... 

An alternative way to preform a channeled plasma consists in exploiting the nanosecond precursor that usually precedes a short femtosecond pulse in the output of a multi-terawatt laser system. In fact, the amplified spontaneous emission (ASE) pedestal has typically an intensity 106-1010 times lower than the main pulse, which, however, can be sufficient to ionize a gas-jet or a solid target. This drawback can be turned into a benefit assuming that this long precursor can prepare the plasma channel for the short pulse propagation. 

A completely different emission process, which can in principle provide table-top ultrashort X-ray sources up to 100 keV has been recently discovered and studied, both from an experimental and a theoretical viewpoint [9]. It can be understood as one consider that the electrons, trapped and accelerated in a plasma wake as described earlier, can also experience, in some cases, a transverse force pulling them toward the beam axis. This force is basically due to the creation of a sort of plasma channel at low electron density, which is a consequence of the ponderomotive force that expels the electrons from the laser beam axis (the ions, due to their larger inertia, being fixed). The trapped electrons thus undergo a sort of wiggler motion, thus producing so-called betatron radiation. 

Picosecond pedestal, 143 Pin-hole camera, 128 Plasma channels, 112, 147, 148 Plasma defocusing, 84, 91 Plasma frequency, 166 Plasma index of refraction, 147 Plasma mirror (PM) technique, 194 Plasma wakefield acceleration, 172 Plasma wavelength, 166 Plasma-induced effects, 83 Polarization, 97 Polarization control, 87 Ponderomotive force, 170 Population inversions, 19 Post-irradiation spectroscopy, 156 Pre-pulse, 143 Propagation, 81 Protein, 102 Pump depletion, 151... 

Figure 19 Photographs of microplasma reactor fabricated by replica molding on a plastic substrate (left) and magnified view of the 10 x 10 array of 400 pm diameter microcavity plasma channels, operating in argon (right) (Anderson et al, 2008 reproduced with permission).

J. C. Kieffer, B. L. Fontaine, F. Martin, R. Mawassi, H. Pepin, F. A. M. Rizk, F. Vidal, P. Couture, H. P. Mercure, C. Potvin, A. Bondiou-Clergerie, I. Gallimberti, Triggering and guiding leader discharges using a plasma channel created by an ultrashort laser, Applied Physics Letters 76, 819 (2000). 

S. Tzortzakis, B. Prade, M. Franco, A. Mysyrowicz, Time evolution of the plasma channel at the trail of a self-guided IR femtosecond laser pulse in air, Optics Commun. 181, 123 (2000)... 

H. Schillinger, R. Sauerbrey, Electrical conductivity of long plasma channels in air generated by self-guided femtosecond laser pulses, Applied Physics B 68, 753 (1999)... 

Fig. 16.9. a,b Typical shadowgraphs of the plasma channels ionized by fast electrons from the Al him (a) and the mushroom-like plasma at the rear of the target (b)... 

Geddes CGR, Toth CS, Van Tilborg J, Esarey E, Schroeder CB, Bmhwiler D, Cary J, Leemans WP. (2004) High-quality electron beams from a laser wakefield accelerator using plasma-channel guiding. Nature 431 538-541. 

Cx43 has four transmembrane, two extracellular and three cytosolic (including the amino and carboxy terminus) domains the residues 1-242 form the plasma channel portion, while the residues 243-382 form the cytosolic tail of Cx43". The length of the cytosolic tail of Cx43 slightly varies between different species and tissues12. 

Sample preparation Dialyze 400 xL plasma against 175 p,L acceptor solution through a Cuprophane membrane (15 kDa cut-off) at 37° for 10 min, inject 500 xL acceptor solution (including the portion used for dialysis) onto column A at 0.71 mL/min, elute the contents of column A onto column B with mobile phase, remove column A from circuit and condition it with 1 mL acceptor solution, elute column B with mobile phase and monitor the effluent. Flush acceptor channel with 5 mL acceptor solution and plasma channel with 8 mL acceptor solution containing 25 p-g/mL TYiton X-100. (Acceptor solution contained 5.9 g NaCl, 4.1 g sodium acetate, 0.3 g KCl, and 1.65 g sodium citrate in 1 L water, adjusted to pH 7.4 with citric acid.)... 

Sample preparation 500 pL Plasma -l- 125 pL 40 mM decanoic acid in MeCN, mix. Dialyze a 100 pL sample against 20 mM pH 7.0 phosphate buffer using a Gilson Cuprophane membrane (molecular mass cut-off 15 kDa). Continuously pump the buffer through the dialysis cell and through column A at 3 mL/min for 9.6 min, backflush the contents of column A onto column B with the mobile phase, monitor the effluent from column B. (After each injection flush plasma channel with 1 mL 0.05% Triton X-100, with 1 mL 1 mM HCl, and with 2 mL water. After each injection flush buffer channel with 3 mL 20 mM pH 7.0 phosphate buffer and condition column A with 1 mL 20 mM pH 7.0 phosphate buffer.)... 

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