Target plate

Because the energy which is imparted to the target by ion bombardment is Anally transformed into thermal energy, the target plate is normally water-cooled in a sputtering apparatus. 

Mechanical attrition is used to remove most of the spent binder. First, dry attrition or abrasion processes crush lumps to grain size. Mechanical abrasion is then used to separate the binder from the sand grains. Sometimes, sand is pneumatically propelled against a metal target plate. The impact of the sand on the plate scrubs off the clay and resin coating from the sand grains. Fines are separated and removed by dry classification. 

In IMS, supportive materials, whose surfaces are coated with conductive materials, are used in principal. In the simplest way, the tissue slices can be placed on a metal MALDI plate directly.9 In this case, however, the target plate must be cleaned carefully after the measurement is over. Currently, the method commonly used is that samples are prepared on a disposable plastic sheet or a glass slide coated with series of conductive materials. In particular, a plastic sheet (ITO sheet) or glass slide (ITO glass slide available from Bruker Daltonics K.K., Billerica, MA, or Sigma, St. Louis, MO) coated with ITO (indium-tin oxide) is useful because it has superior optical transparency... 

Solutions of the analyte and the matrix (from nanolitre to microlitre amounts) are deposited or spotted on a flat metal target plate. Owing to evaporation of the solvent, matrix and analyte co-crystallize. Short laser pulses (1 20 ns) bombard the solid and cause the sample and matrix to be volatilized. The formation of ions occurs by acid base reaction between the ionized matrix molecules and the analyte molecules (Figure 2.5). 

B Magnetic field F Target plate (pump housing) as the third electrode K Cathode grid... 

The measured driver plate impact velocity or the shock velocity in the target plate, whose shock properties are known, defined the incident shock strength. An impedance match at the target plate-explosive interface using the measured overdriven deton velocity then defined the corresponding detonation pressure and particle velocity... 

Fig 23 shows the deformation obtd soon after impact. The end of the AI nose cap has opened up, but the longitudinal section of the cap has not yet split open. Fig 24 shows the deformation late in the impact. The Al cap has completely failed by longitudinal splitting, and the steel rim of the projectile body is in near contact with the target plate. This is called the "pinch stage and the most violent reactions from a Susan type impact... 

Then a final apparently steady, deton was established at 8280 m/sec 4) Skidmore Hart (Bet 88) produced overdriven detonation waves in Comp B carrying increased velocities and pressures up to twice the C-J pressure by an explosive driven plate impact technique. The basis of the technique is to explosively propel a metal driver plat e at a similar target plate on which rests a sample layer of expl backed by a further layer of inert solid. When the driver plate vel is sufficiently high this process generates a steady overdriven deton wave in the expl unless (or until) it is overtaken by the rarefaction wave from the rear of the driver plate. 

Bullet Impace Fuze, MI AI for Demolition Snake M3 consists of a body (which contains a detonator and two shaped-charge boosters), a target plate of 3/8-inch thick steel and a spring mounted on three studs. The target plate bears on a firing pin which is restrained by a shear pin and safety fork. The fork must be removed before the fuze can be operated. 

Ejecta. Jet fragment ejected essentially beyond primary target plate in the testing of shaped charges... 

A Gilson liquid handler was programmed with the Unipoint software to dilute and reformat failed samples. A volume of 120 pi of solvent (methanol unless specified otherwise) was added to each failed vial. The solution was taken up and released by the sampling needle three times to ensure efficient mixing. A fraction of the liquid was then transferred to the target plate. The fraction volume was determined on the Excel template by the dilution factor, for example 40 pi for 2 1 dilution. Solvent was allowed to evaporate at ambient temperature from the new plate, and 200 pi of solvent was then added to each well in the plate. The new plate, reformatted and compressed, was analyzed with the MUX-LCT system using the sample fist from the template. Using this new format, the 24 samples in the example above (Fig. 6) were reanalyzed in three runs (13.5 min) instead of 24 runs (108 min). This represents an 8-fold improvement in efficiency. 

There are several direct ways to transfer tissue slices to the sample plate. First, the frozen tissue slice is gently positioned on the cold target plate (—15°C) using an artist s bmsh and thawmounted onto the plate by quickly moving it out of the cryostat chamber the frozen section then adheres to the MALDI plate when held at room temperature. As an alternative procedure, one can attach the section to a doublesided transparent tape, which is then glued on the sample plate (Schwartz et al., 2003). 

To resolve the primordial terrestrial noble gas, it would be useful to examine major noble gas reservoirs in the early solar system, which could have supplied noble gases to the Earth. As we discussed in Chapter 3, two major noble gas components occur very widely in the solar system and can be a potential source for the terrestrial noble gas. They are solar noble gas (representative of the sun), which is generally assumed to be best represented by solar wind noble gas implanted on Al-foil target plates on the moon (elemental ratio) and on lunar breccia (isotopic ratio) (e.g., Ozima et al., 1998), and Q phase noble gas (see Wieler, 1994, for a review), which occurs very widely in various chondrites. Next we will compare the bulk Earth noble gas, which we assume to be represented by atmospheric noble gas with these two major noble gas components in the solar system. 

To prepare a sample, an analyte of interest is dissolved in an appropriate solvent at a concentration of about 20 pM. This solution and a matrix solution (50 50, vol/vol) are mixed with an appropriate matrix-analyte ratio at >10 1 in a small vial. If an internal standard is used, the internal standard is dissolved in the sample solution before combining with the matrix. A tiny drop (0.5-2.0 pi) of the final solution is transferred and applied to the MADLI sample target plate which can be a stainless steel or a Gold-coated MALDI sample plate. The sample-matrix solution is allowed to dry at room temperature and under normal pressure for several minutes until all of solvents are completely evaporated. The precipitate is the cocrystallization of matrix and analyte, ready for MALDI analysis. 

There are several ways to coat a MALDI plate. One is two-layer overlayer [62,63] In this method, the first layer on the MALDI target plate comprises the densely packed matrix microcrystals formed by the quick solvent evaporation of a matrix solution in acetone or a mixture of acetonitrile and water at room temperature. A mixture solution containing both matrix and sample is then deposited onto the first layer of small crystals to form uniform analyte-matrix microcrystals. The overlayer method is reported to provide improved results, particularly for analyses of proteins and peptides [64-66],... 

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