X-ray pinhole camera setups used in the Atomki ECR Laboratory for plasma diagnostics.

Imaging of the electron cyclotron resonance (ECR) plasmas by using CCD camera in combination with a pinhole is a non-destructive diagnostics method to record the strongly inhomogeneous spatial density distribution of the X-ray emitted by the plasma and by the chamber walls. This method can provide information on the location of the collisions between warm electrons and multiple charged ions/atoms, opening the possibility to investigate the direct effect of the ion source tuning parameters to the plasma structure. The first successful experiment with a pinhole X-ray camera was carried out in the Atomki ECR Laboratory more than 10 years ago. The goal of that experiment was to make the first ECR X-ray photos and to carry out simple studies on the effect of some setting parameters (magnetic field, extraction, disc voltage, gas mixing, etc.). Recently, intensive efforts were taken to investigate now the effect of different RF resonant modes to the plasma structure. Comparing to the 2002 experiment, this campaign used wider instrumental stock: CCD camera with a lead pinhole was placed at the injection side allowing X-ray imaging and beam extraction simultaneously. Additionally, Silicon Drift Detector (SDD) and High Purity Germanium (HPGe) detectors were installed to characterize the volumetric X-ray emission rate caused by the warm and hot electron domains. In this paper, detailed comparison study on the two X-ray camera and detector setups and also on the technical and scientific goals of the experiments is presented.

Fast camera studies at an electron cyclotron resonance table plasma generator.

A simple table-size ECR plasma generator operates in the ATOMKI without axial magnetic trap and without any particle extraction tool. Radial plasma confinement is ensured by a NdFeB hexapole. The table-top ECR is a simplified version of the 14 GHz ATOMKI-ECRIS. Plasma diagnostics experiments are planned to be performed at this device before installing the measurement setting at the "big" ECRIS. Recently, the plasma generator has been operated in pulsed RF mode in order to investigate the time evolution of the ECR plasma in two different ways. (1) The visible light radiation emitted by the plasma was investigated by the frames of a fast camera images with 1 ms temporal resolution. Since the visible light photographs are in strong correlation with the two-dimensional spatial distribution of the cold electron components of the plasma it can be important to understand better the transient processes just after the breakdown and just after the glow. (2) The time-resolved ion current on a specially shaped electrode was measured simultaneously in order to compare it with the visible light photographs. The response of the plasma was detected by changing some external setting parameters (gas pressure and microwave power) and was described in this paper.

Molecular and negative ion production by a standard electron cyclotron resonance ion source.

Molecular and negative ion beams, usually produced in special ion sources, play an increasingly important role in fundamental and applied atomic physics. The ATOMKI-ECRIS is a standard ECR ion source, designed to provide highly charged ion (HCI) plasmas and beams. In the present work, H(-), O(-), OH(-), O(2)(-), C(-), C(60)(-) negative ions and H(2)(+), H(3)(+), OH(+), H(2)O(+), H(3)O(+), O(2)(+) positive molecular ions were generated in this HCI-ECRIS. Without any major modification in the source and without any commonly applied tricks (such as usage of cesium or magnetic filter), negative ion beams of several µA and positive molecular ion beams in the mA range were successfully obtained.

Status and special features of the Atomki ECR ion source.

The ECR ion source has been operating in ATOMKI (Debrecen) since 1996. During the past 15 years lots of minor and numerous major technical modifications have been carried out on the ECRIS. Many of these changes aimed the increasing of beams charge, intensity, and the widening of the ion choice. Another group of the modifications were performed to develop special, non-standard operation modes or to produce peculiar plasmas and beams.

Electron cyclotron resonance plasma photos.

In order to observe and study systematically the plasma of electron cyclotron resonance (ECR) ion sources (ECRIS) we made a high number of high-resolution visible light plasma photos and movies in the ATOMKI ECRIS Laboratory. This required building the ECR ion source into an open ECR plasma device, temporarily. An 8MP digital camera was used to record photos of plasmas made from Ne, Ar, and Kr gases and from their mixtures. We studied and recorded the effect of ion source setting parameters (gas pressure, gas composition, magnetic field, and microwave power) to the shape, color, and structure of the plasma. The analysis of the photo series gave us many qualitative and numerous valuable physical information on the nature of ECR plasmas.

Structure and drug release of lamellar liquid crystals containing glycerol.

Lamellar lyotropic liquid crystalline (LLC) systems are thermodynamically stable, optically isotropic systems, which are formed with low energy input. New possibilities for the development of controlled drug delivery systems are inherent in these systems due to their stability and special skin-similarly structure. The present aim was to formulate multicomponent LLC systems with a relatively low surfactant content, composed of materials official in the European Pharmacopoeia 4th. Polarizing light microscopic examination of the samples was carried out, together with TEM observation of replicas produced by freeze-fractured technique for the purpose of demonstrating the presence of lamellar LC domains. Our LLC samples contained: Brij 96 (poly-oxyethylene-10-oleyl ether) with water, liquid petrolatum (LP) and glycerol in a given concentration range. The interlamellar repeated distance (d(L)) confirming the existence of a regular structure was determined by means of X-ray diffraction. The d(L) and G'values of the samples changed according to a maximum curve with increasing glycerol concentration up to 40% (w/w). A prolonged drug release was observed in case of the very water-soluble ephedrine hydrochloride and the same phenomena was observed in the case of tenoxicam, which is practically insoluble in water.

The effect of liquid crystalline structure on chlorhexidine diacetate release.

The aim of this study was to examine different liquid crystalline preparations containing chlorhexidine diacetate and to find connection between their structure and the kinetic of drug release. Nonionic surfactant, Synperonic A7 (PEG(7)-C(13-15)) was selected for the preparation of the examined liquid crystalline systems. Mixtures of different ratios of Synperonic A7 and water were produced. By increasing the water content of the systems, lamellar and hexagonal liquid crystal structures were observed. For the analysis of the prepared liquid crystalline systems polarising microscopy, rheology study, differential scanning calorimetry and dynamic swelling tests were carried out. The chlorhexidine diacetate release was examined by Franz-type vertical diffusion cell apparatus. The chlorhexidine diacetate release from hexagonal liquid crystalline preparations was characterised by zero-order release kinetics, while the drug release from lamellar liquid crystalline systems was described by anomalous (non-Fickian) transport. The results indicate that the drug release kinetic is strongly dependent on the liquid crystalline structure.

[Positron emission tomography: foundations and applications]. / Pozitron emissziós tomográfia: alapok és alkalmazások.

Positron emission tomography (PET) is a non-invasive biomedical imaging technique whereby the distribution of biological tracer molecules, labelled by positron emitting isotopes, in the living body can be studied quantitatively. As theoretically an metabolically active molecule can be labelled, the technique is applicable to the measurement of any biochemical or physiological process in proper anatomical context. The introduction of PET has revolutionised the exploration of normal physiological functions. With the help of technique, among others, anatomical structures underlying mental functions can be localised in the human brain, the receptor architecture of the nervous system can be mapped, or the kinetics of pharmacons can be properly measured and modelled. In the clinical practice, PET has proven to be a uniquely useful diagnostic technique in neurology, psychiatry, cardiology, and oncology in establishing primary diagnosis and differential diagnosis, designing therapeutic interventions as well as assessing their efficacy. Hungary's and Central European region's first PET center has been established at the University Medical School in Debrecen.