Laser ablation system

Laser ablation systems hold considerable promise if restenosis (reblocking of the arteries) rates are reduced. The rate as of 1995 is 30%, typically within six months. Mechanical or atherectomy devices to cut, shave, or pulverize plaque have been tested extensively in coronary arteries. Some of these have also been approved for peripheral use. The future of angioplasty, beyond the tremendous success of conventional balloon catheters, depends on approaches that can reduce restenosis rates. For example, if appHcation of a dmg to the lesion site turns out to be the solution to restenosis, balloon catheters would be used for both dilating the vessel and deUvering the dmg. An understanding of what happens to the arterial walls, at the cellular level, when these walls are subjected to the various types of angioplasty may need to come first. 

GeoLas,The high resolution UV laser Ablation system. Prospect of the Company MicroLas Lasersystem GmbH, Goettingen, Germany. 

A LSX-200 Plus Laser Ablation System (CETAC Technologies, Omaha, Nebraska, USA), using a Nd YAG laser with a wavelength of 266 nm, was used for the analyses. A spot size of 100 pm was selected. Sufficient volume of ablated... 

ES and the first laser ablation system on which Barringer held a patent for many years. 

Silicon isotope ratios have been generally measured by fluorination (Douthitt 1982 Ding et al. 1996). However, the method is time consuming and potentially hazardous, therefore, more recently MC-ICP-MS techniques have been introduced (Cardinal et al. 2003 Engstrom et al. 2006). Determinations with SIMS have been carried out by Robert and Chaussidon (2006). Very recently, Chmeleff et al. (2008) have shown that a UV-femtosecond laser ablation system coupled with MC-ICP-MS gives S Si and 5 °Si-values with very high precision. 

Figure 5.1 Main parts of an inductively coupled plasma mass spectrometer sample introduction systems (left column), e.g., Meinhard or MicroMist nebulizer with cyclonic spray chamber, ultrasonic nebulizer, microconcentric nebulizer and laser ablation system (all from CETAC Technologies), ion source (middle column) and several types of mass spectrometers, (a) Agilent 7500 from Agilent, (b) Platform from CV Instruments, or (c) Element from Thermo Fisher Scientific. (Parts of this figure were reproduced with permission from CETAC Technologies, Agilent, CV Instruments and Thermo Tisher Scientific, respectively.)...

Furthermore, a few commercial excimer laser ablation systems are available on the analytical market, for the analysis of highest purity glasses, diamonds and highly transparent materials,... 

The experimental arrangement of LA-ICP-MS using a powerful laser ablation system coupled to a double-focusing sector field ICP-MS (Element, Thermo Fisher Scientific, Bremen) is shown in Figure 5.22. A cooled laser ablation chamber using two Peltier elements in serial connection... 

Figure 5.22 Schematic of laser ablation inductively coupled plasma mass spectrometer a laser ablation system (wa velength 213 nm) is coupled to a double-focusing sector field ICP-MS (Element, Thermo Fisher Scientific, Bremen). The cooled laser ablation chamber using two Peltier elements was developed in the author s laboratoryJ26 (M. V. Zoriy, M. Kayser, A. Izmer, C. Pickhardt and J. S. Becker, Int. J. Mass Spectrom., 242, 297 (2005). Reproduced by permission of Elsevier.)...

Figure 5.23 LA-ICP-MS by combining a quadrupole based ICP-MS with a CETAC LSX 2 13 laser ablation system.

For an accurate in situ 234U/238U and 230Th/232Th isotope microanalysis of silicate glasses and iron oxides, an excimer laser ablation system (HelEx, Lambda Physik Compex llOi ArF ... 

The laser ablation system consists of a high-power pulsed laser, optics to focus the laser at or near the surface of the sample, and an ablation cell. Small ablated particles are swept out of the ablation cell and carried into the ICP in a flowing gas. Often a microscope lens and video camera are positioned to allow the operator to view the sample surface before and after ablation. A high-quality microscope and precise positioning of the sample relative to the laser beam are essential for good spatially resolved sampling. 

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