[en] A technique is presented which greatly facilitates the focusing of nuclear microprobe ion beams down to sizes of about one micrometer. It is based on the visual observation of the pattern created by the ion beam when impinging on a scintillating screen after first having passed through a 2000 mesh copper grid (grid period 12.7 μm) placed in the image plane. No additional electronic components or detectors are required. Apart from aiding the user in the focusing of the beam, the generated patterns give information concerning the quality of the ion focusing system and is therfore recommended as a permanent part of any nuclear microprobe setup. (orig.)

[en] This paper reports a study of colours and inks of an ancient Egyptian papyrus using an external proton microprobe in PIXE mode. Representing the Book of the Dead, this papyrus is dated from the 19th dynasty, New Kingdom (c.1295-1186 BC). Elemental maps were obtained by moving the papyrus under a fixed focused external beam using a motorised support. The maps were compared to photographic pictures taken in visible light. Inks used in the hieroglyph text appeared to be based on carbon (black) and iron oxide (red). Coloured drawings illustrating the text showed a wider palette: hematite, ochre, orpiment, Egyptian blue, verdigris. Most intriguing was the observation in several parts of the drawing of a whitish pigment containing strontium. Deposits of strontium-rich minerals (e.g. strontianite, celestite) have been identified in Egypt. The exact nature and the archaeological implications of this pigment have still to be determined. Finally, fine powder and coarse grains of arsenic oxide were observed, probably remaining from an early preservation treatment against insect attacks after excavation

[en] A method for elemental analyses of individual aerosol particles by means of a focused proton beam and the PIXE method is demonstrated. Preliminary tests of the method have been performed successfully and several aspects of the results are discussed. (author)

[en] This paper summarizes some of the improvements made at the nuclear microprobe facility in Lund. The analytical facility is briefly described, and problems concerning quantification are discussed. The external beam facility has been applied to the analysis of both historical documents and geological materials. (orig.)

[en] The overall technical status of the Lund nuclear microprobe is presented. Several parts of the instrument have been replaced by newly developed systems. In this paper the main emphasis is directed to a newly installed, versatile specimen chamber. The special characteristics are: very quick opening and sample-changing procedures, many samples of varying sizes can be housed simultaneously and several detector systems can be used. (orig.)

[en] The grid-shadow technique has proved to be an important tool for the characterization of the quadrupole lenses used for focusing the ion beam in nuclear microprobes. A technique is described which can identify and distinguish between beam aberrations, seen in the grid-shadow patterns, caused by parasitic multipoles in the lenses from those caused by stray external fields. Also presented is an on-line method to correct for the internal parasitic fields in the lenses by observing the grid-shadow patterns, thereby improving the spatial resolution in the nuclear microprobe. (orig.)

[en] A review of recent advances in high-energy ion beam analysis at the Lund Institute of Technology is presented. A nonvacuum specimen chamber allows chemical speciation using a combination of ion beam analysis and controlled heating. The development of a new versatile scanning proton microbeam based on a new dedicated accelerator, an achromatic triplet lens and an advanced specimen chamber is outlined together with the performance of a microVAX-II/VMEbus-based data acquisition system. (orig.)

[en] The importance of statistical evaluation of multielemental data is illustrated using the data collected in a macro- and micro-PIXE analysis of human brain tumours. By employing a multivariate statistical classification methodology (SIMCA) it was shown that the total information collected from each specimen separates three types of tissue: High malignant, less malignant and normal brain tissue. This makes a classification of a given specimen possible based on the elemental concentrations. Partial least squares regression (PLS), a multivariate regression method, made it possible to study the relative importance of the examined nine trace elements, the dry/wet weight ratio and the age of the patient in predicting the survival time after operation for patients with the high malignant form, astrocytomas grade III-IV. The elemental maps from a microprobe analysis were also subjected to multivariate analysis. This showed that the six elements sorted into maps could be presented in three maps containing all the relevant information. The intensity in these maps is proportional to the value (score) of the actual pixel along the calculated principal components. (orig.)

[en] This paper gives a description of the recently installed scanning nuclear microprobe at the Accelerateur Grand Louvre d'Analyse Elementaire (AGLAE) ion beam laboratory. The setup is based on the commercially available system from Oxford Microbeam, including a triplet focusing system, target chamber, slits and scanning coils, Some modifications have been made to simplify the procedure for extracting and forming the beam probe. Also, a high performance beam scanning and data acquisition system has been adopted. (orig.)