Sputtering sources

Fig. 3. Schematics of magnetic confinement geometries (a) planar and (b) cylindrical geometries for magnetron sputtering sources (24) (c) open-ended...

Another study (200) presented IR data for a number of hydride and deuteride species. Using matrix-isolation spectroscopy in conjunction with a hollow-cathode, sputtering source (the apparatus for which is shown in Fig. 36), the IR-active vibrations of the diatomic hydrides and deuterides of aluminum, copper, and nickel were observed. The vibra-... 

A 2-in diameter (5.1cm) magnetron sputter source (Kurt J. Lesker - Torus type magnetron source) was fed into the top of the deposition chamber and positioned 12 cm above a custom made ( 120 cm ) stainless steel (SS)... 

Removal of all possible contaminants is not the only reason for sample preparation, since each clean and purified material has then to be converted into the chemical form suitable for the accelerator ion source. In most cases (as explained in the previous section), samples are put into the caesium sputtering source as graphite, solid elemental carbon, and for this reason samples are first burnt and then chemically reduced to graphite. 

The reasons will be clearer after Section 16.4, where AMS radiocarbon sample preparation procedures will be described. Now we would simply like to recall that in preparing graphite pellets for the sputtering source, after a physical chemical cleaning, samples to be dated are usually combusted to obtain C02, which is then converted to graphite by a further step. In this process, the main problem with small samples (a few tens of micrograms) is the possible introduction of contamination. 

C. Bronk Ramsey and R.E.M. Hedges, Carbon dioxide sputter source development at Oxford,... 

During the search for 36C1 at Rochester, 5-13 pA of Cl ions were produced from silver chloride in the cesium sputter source. The detection techniques were basically similar to those discussed for 14C. The samples and the results obtained are given in Table 2. 

We have recently commissioned a new reflected beam Cs sputter source [6] to be used in these experiments. This source is better suited to this work than the old non-reflecting source, as the Cs beam is focussed to sputter ions off a very small pill or plug of material. This gives an ion beam with good optical properties (since the source spot size is small) and allows the use of very small samples. We are currently working with samples of 1-5 mg of BeO or graphite. 

All carbon samples could easily be oxidized to C02, a form of the sample greatly preferred by most users, for many reasons. Neither the on-line or dedicated electrostatic accelerators under construction have succeeded in overcoming the problem of too much memory of C02 gas. Consequently, the sample presented to the cesium sputter beam source will probably have to be a solid. The cesium sputter source is the most likely to be used because it can produce negative ions of carbon in microampere beams. 

Cs-Beam Sputter Source for Negative Eons 40 Samples... 

This is just what has been done with Ag2. A sputtering source followed by a phase-space compressor chamber provided a beam of cooled negative cluster ions of many sizes. From these, the dimers were selected, accumulated in a quadrupole trap, and photodetached with a femtosecond, titanium-sapphire laser. After photodetachment by a 60-fs pulse, the neutral dimers oscillate, causing corresponding oscillations in the ionization cross section, in turn generating the oscillations that dominate the intensity pattern in Fig. 11. This is a simple phenomenon, yielding in a simple way the... 

R. Middleton, J. Klein, Production of metastable negative ions in a cesium sputter source Verification of the existence of N2 and CO. Phys. Rev. A 60, 3786-3799 (1999)... 

Fig. 5.31. (a) Cross-section (reprinted from [123]) and industrial construction (b) of rotatable magnetron sputter sources... 

Los and coworkers at the FOM institute also used a sputtering source to study ionization cross sections of alkali metal atom collisions with O2 at relative velocities below 13 km s . These authors used magnetic fields in the charged particle detection part of their experiment, allowing them to differentiate between negative ions and e . The K + O2 measurements of Moutinho et al. are shown in Fig. 18. They are compared with the K(4 P -> 4 5) resonance line excitation cross sections of Lacmann and Herschbach after scaling them to the estimated cross section of Kempter et A dotted line indicates the measurements of Kempter et al. in-... 

Another possibility is the sputter ion source. Here inside the source gaseous ions are accelerated to the reflector electrode containing an insert made of the element to be vaporized. Due to the sputtering effect, the material evaporates and is converted into ions. This technique is universal and applicable for all elements. Fig. 17 shows a sketch of a sputter source ... 

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