Recent measurements of soft X-ray emission from the DPF-1000U facility

• Autorzy: Surała W. , Sadowski M. J. , Paduch M. , Zielinska E. , Tomaszewski K.

Identyfikatory

DOI

10.1515/nuka-2015-0055

• Konferencja: Kudowa Summer School „Towards Fusion Energy” (12th ; 9-13.06.2014 ; Kudowa Zdrój, Poland)
• Języki publikacji: EN

Abstrakty

EN

Soft X-ray imaging is a very useful diagnostic technique in plasma-focus (PF) experiments. This paper reports results of four experimental sessions which were carried out at the DPF-1000U plasma-focus facility in 2013 and 2014. Over 200 discharges were performed at various experimental conditions. Measurements were taken using two X-ray pinhole cameras with a line of sight perpendicular to the z-axis, at different azimuthal angles (about 20° and 200°), and looking towards the centre of the PF-pinch column. They were equipped with diaphragms 1000 μm or 200–300 μm in diameter and coated with filters of 500 μm Al foil and 10 μm Be foil, respectively. Data on the neutron emission were collected with silver activation counters. For time-resolved measurements the use was made of four PIN diodes equipped with various fi lters and oriented towards the centre of the PF-column, in the direction perpendicular to the electrode axis. The recorded X-ray images revealed that when the additional gas-puff system is activated during the discharge, the stability of the discharge is improved. The data collected in these experiments confi rmed the appearance of a filamentary fi ne structure in the PF discharges. In the past years the formation of such fi laments was observed in many Z-pinch type experiments. Some of the recorded X-ray images have also revealed the appearance of the so-called hot- -spots, i.e. small plasma regions of a very intense X-ray emission. Such a phenomenon was observed before in many PF experiments, e.g. in the MAJA-PF device, but it has not been investigated so far in a large facility such as the DPF-1000U. The time-resolved measurements provided the evidence of a time lapse between the X-ray emission from plasma regions located at different distance from the anode surface. The formation of distinct ‘hot-spots’ in different instants of the DPF-1000U discharge was also observed.

Słowa kluczowe

EN

plasma focus; X-ray emission; X-ray images; gas puffing; filaments; hot spots

• Wydawca: Institute of Nuclear Chemistry and Technology
• Czasopismo: Nukleonika
• Rocznik: 2015
• Tom: Vol. 60, No. 2
• Strony: 303--308
• Opis fizyczny: Bibliogr. 6 poz., rys.

Twórcy

autor

Surała W.

• National Centre for Nuclear Research (NCBJ), 7 Andrzeja Soltana Str., 05-400 Otwock/Swierk, Poland, Tel.: [phone], Mobile: [phone], Fax: [phone],

autor

Sadowski M. J.

• National Centre for Nuclear Research (NCBJ), 7 Andrzeja Soltana Str., 05-400 Otwock/Swierk, Poland
• Institute of Plasma Physics and Laser Microfusion (IPPLM), 23 Hery Str., 01-497 Warsaw, Poland

autor

Paduch M.

• Institute of Plasma Physics and Laser Microfusion (IPPLM), 23 Hery Str., 01-497 Warsaw, Poland

autor

Zielinska E.

• Institute of Plasma Physics and Laser Microfusion (IPPLM), 23 Hery Str., 01-497 Warsaw, Poland

autor

Tomaszewski K.

• ACS Sp. z o.o., 23 Hery Str., 01-497 Warsaw, Poland

Bibliografia

• 1. Lebert, R., Neff, W., & Rothweiler, D. (1996). Pinch plasma source for X-ray microscopy with nanosecond exposure time. X-Ray Sci. Technol., 6, 107–140. DOI:10.3233/XST-1996-6201.
• 2. Bernard, A., Bruzzone, H., Choi, P., Chuaqui, H., Gribkov, V., Herrera, J., Hirano, K., Krejci, A., Lee, S., Luo, C., Mezzetti, F., Sadowski, M. J., Schmidt, H., Ware, K., Wong, C. S., & Zoita, V. (1998). Scientific status of plasma-focus research. J. Moscow Phys. Soc., 8, 93–170.
• 3. Sadowski, M., Herold, H., Schmidt, H., & Shakhatre, M. (1984). Filamentary structure of the pinch column in plasma focus discharges. Phys. Lett. A,105, 117–123. DOI: 10.1016/0375-9601(84)90650-9.
• 4. Scholz, M., Drozdowicz, K., Karpinski, L., Woźnicka, U., Krauz, V., Kubes, P., Paduch, M., Sadowski, M. J., Czaus, K., Malinowski, K., Kwiatkowski, R., Skladnik-Sadowska, E., & Zebrowski, J. (2013). Status of plasma-focus research in Poland. In Proceedings of International Conference PLASMA-2013, September 2–6, 2013 (T10). Warsaw, Poland. http://plasma2013. ipplm.pl/.
• 5. Sadowski, M. J., & Scholz, M. (2008). The main issues of research on dense magnetised plasmas in PF discharges. Plasma Sources Sci. Techn., 17, 024001. DOI: 10.1088/0963-0252/17/2/024001.
• 6. Jakubowski, L., Sadowski, M., Baronova, E. O., & Vikhrev, V. V. (1997). Study of X-ray polarization and e-beams generated during hot-spots formation in PF-discharges. Dense Z-pinches. AIP Conf. Proc., 409, 443–447. DOI: 10.1063/1.53825.