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  • Author: Natalia Krawczyk x
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Comparison of silicon drift detectors made by Amptek and PNDetectors in application to the PHA system for W7-X

Abstract

The paper presents comparison of two silicon drift detectors (SDD), one made by Amptek, USA, and the second one by PNDetector, Germany, which are considered for a soft X-ray diagnostic system for W7-X. The sensitive area of the first one is 7 mm2 × 450 μm and the second one is 10 mm2 × 450 μm. The first detector is cooled by a double-stage Peltier element, while the second detector is cooled by single-stage Peltier element. Each one is equipped with a field-effect transistor (FET). In the detector from Amptek, the FET is mounted separately, while in the detector from PNDetector, the FET is integrated on the chip. The nominal energy resolution given by the producers of the first and the second one is 136 eV@5.9 keV (at -50°C) and 132 eV@5.9 keV (at -20°C), respectively. Owing to many advantages, the investigated detectors are good candidates for soft X-ray measurements in magnetic confinement devices. They are suitable for soft X-ray diagnostics, like the pulse height analysis (PHA) system for the stellarator Wendelstein 7-X, which has been developed and manufactured at the Institute of Plasma Physics and Laser Microfusion (IPPLM), Warsaw, in collaboration with the Max Planck Institute for Plasma Physics (IPP), Greifswald. The diagnostic is important for the measurements of plasma electron temperature, impurities content, and possible suprathermal tails in the spectra. In order to choose the best type of detector, analysis of technical parameters and laboratory tests were done. Detailed studies show that the most suitable detector for the PHA diagnostics is the PNDetector.

Open access
Child’s problems with Synovial Sarcoma – case study

Abstract

Introduction. Soft tissue sarcomas are a heterogeneous group of malignant tumors derived from the embryonic mesenchymal and neuroectodermal tissue. In Poland, they constitute about 7% of all childhood malignant tumors and represent the fifth group of the most common tumorous under the age of 16 after leukemia, central nervous system tumor, lymphoma and neuroblastoma. When starting treatment of a child with cancer, the following points should be taken into account: the type, localization and size of cancer with its dynamics and the stage of disease, the general condition and the age of a patient. The contemporary treatment of patients with malignant tumor is combined and multi-profile. This treatment consists of multidrug chemotherapy, surgery, radiotherapy, rehabilitation and palliative care.

In order to analyze care problems of a child with malignant tumor, we present the case of a girl with Synovial Sarcoma who was diagnosed after a year and a half since the first symptoms have occurred. It had a significant impact on the girl’s health condition, emotional and social development as well as on the functioning of her whole family.

Aim. The aim of the study was to present the problem associated with a care of a child with malignant tumor based on the analysis of a chosen clinical occurrence.

Material and methods. Analysis of medical records of the child was diagnosed thenar tumor of the left hand Synovial Sarcoma and the anamnestic interview with the family.

Results and conclusions. Problems of the child diagnosed with cancer are significantly associated with somatic symptoms of the disease such as pain, or complications of chemotherapy. Equally important are the issues related to child mental sphere. A difficult problem is anxiety and impaired sense of security, particularly in cases when the diagnosis process is very long.

Open access
Luminescence chronostratigraphy for the loess deposits in Złota, Poland

Abstract

Loess formations in Poland display a close relationship with cooling and warming trends of the Northern Hemisphere during the Pleistocene. Loess sequences sensitively record regional palaeoclimatic and palaeoecological changes. The Złota loess profile (21°39’E, 50°39’N) provides a unique opportunity to reconstruct climate conditions in the past in this part of Poland. This continuous sequence of loess and palaeosol deposits allows to distinguish between warmer and more humid climate which is favourable for soil development and much colder and dry periods which are conducive to loess accumulation. The silty and sandy aeolian material originates mainly from weathered rock surfaces affected by frost shattering or from glaciofluvial/fluvial deposits of river flood plains. In Poland, loess and loess-like formations occur in the southern part of the country, mostly in the south polish uplands, i.e. in the Lublin, Sandomierz, and Cracow Uplands. We used different techniques to establish a chronological framework for this site. 21 samples for luminescence dating were collected from the investigated loess profile in Złota. Infrared post-IR IRSL dating method was applied to the polymineral fine grains (4–11µm). The dating results are accompanied by detailed analyses of the geochemical composition, organic carbon and carbonate. Also, analysis of magnetic susceptibility and grain-size distribution were investigated. Based on such a large stratigraphic dataset an age-depth model using OxCal has also been constructed for this site.

Open access
Studies of plasma interactions with tungsten targets in PF-1000U facility

Abstract

This paper presents results of experimental studies of tungsten samples of 99.95% purity, which were irradiated by intense plasma-ion streams. The behaviour of tungsten, and particularly its structural change induced by high plasma loads, is of great importance for fusion technology. The reported measurements were performed within a modified PF-1000U plasma-focus facility operated at the IFPiLM in Warsaw, Poland. The working gas was pure deuterium. In order to determine the main plasma parameters and to study the behaviour of impurities at different instants of the plasma discharge, the optical emission spectroscopy was used. The dependence of plasma parameters on the initial charging voltage (16, 19 and 21 kV) was studied. Detailed optical measurements were performed during interactions of a plasma stream with the tungsten samples placed at the z-axis of the facility, at a distance of 6 cm from the electrode outlets. The recorded spectra showed distinct WI and WII spectral lines. Investigation of a target surface morphology, after its irradiation by intense plasma streams, was performed by means of an optical microscope. The observations revealed that some amounts of the electrodes material (mainly copper) were deposited upon the irradiated sample surface. In all the cases, melted zones were observed upon the irradiated target surface, and in experiments performed at the highest charging voltage there were formed some cracks.

Open access