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Recent ion measurements within the modified DPF-1000U facility

100%

Kwiatkowski R., Czaus K., Skladnik-Sadowska E., Sadowski M. J., Zaloga D. R., Paduch M., Zielinska E.

issue 2

297-302

In this note we describe measurements of ion beams emitted along the z-axis of the DPF-1000U facility operated at 23 kV, 334 kJ, and with the initial deuterium pressure of 1.6–2 hPa. The DPF-1000U device was recently renewed and equipped with a dynamic gas-puff valve placed inside the inner electrode. The investigated ions were recorded by means of ion pinhole cameras equipped with solid state nuclear track detectors of the PM-355® (PADC) type. The energy spectra of ions were determined using a Thomson spectrometer placed on the symmetry axis at a distance of 160 cm from the electrodes outlets. The ion images recorded during discharges performed under different experimental conditions show that the ion beams have a complex structure, usually in the form of a central bunch and an annular stream composed of many micro-beams. Energies of the registered deuterons have been in the range of 30–700 keV, while the fast protons (which originated from the hydrogen remnants) had energies in the range of 300–850 keV.

Comparison of optical spectra recorded during DPF-1000U plasma experiments with gas-puffing

84%

Zaloga D. R., Skladnik-Sadowska E., Kubkowska M., Ladygina M. S., Malinowski K., Kwiatkowski R., Sadowski M. J., Paduch M., Zielinska E., Makhlaj V. A.

issue 2

309-314

The results are presented of the optical spectra measurements for free plasma streams generated with the use of the modified DPF-1000U machine. This facility was recently equipped with a gas injection system (the so-called gas-puff) placed on the symmetry axis behind the central opening in the inner electrode. The DPF-1000U experimental chamber was filled up with pure deuterium at the initial pressure of 1.6 or 2.4 mbar. Additionally, when the use was made of the gas-puff system about 1 cm3 of pure deuterium was injected at the pressure of 2 bars. The gas injection was initiated 1.5 or 2 ms before the triggering of the main discharge. The investigated plasma discharges were powered from a condenser bank charged initially to 23 kV (corresponding to the energy of 352 kJ), and the maximum discharge current amounted to about 1.8 MA. In order to investigate properties of a dense plasma column formed during DPF-1000U discharges the use was made of the optical emission spectroscopy. The optical spectra were recorded along the line of sight perpendicular to the vacuum chamber, using a Mechelle®900 spectrometer. The recent analysis of all the recorded spectra made it possible to compare the temporal changes in the electron density of a freely propagating plasma stream for discharges without and with the gas-puffing. Using this data an appropriate mode of operation of the DPF-1000U facility could be determined.

Study of tungsten surface interaction with plasma streams at DPF-1000U

68%

Ladygina M. S., Skladnik-Sadowska E., Zaloga D. R., Malinowski K., Sadowski M. J., Kubkowska M., Kowalska-Strzeciwilk E., Paduch M., Zielinska E., Miklaszewski R., Garkusha I. E., Gribkov V. A.

issue 2

293-296

In this note experimental studies of tungsten (W) samples irradiated by intense plasma-ion streams are reported. Measurements were performed using the modified plasma focus device DPF-1000U equipped with an axial gas-puffing system. The main diagnostic tool was a Mechelle®900 optical spectrometer. The electron density of a freely propagating plasma stream (i.e., the plasma stream observed without any target inside the vacuum chamber) was estimated on the basis of the half-width of the Dβ spectral line, taking into account the linear Stark effect. For a freely propagating plasma stream the maximum electron density amounted to about 1.3 × 1017 cm−3 and was reached during the maximum plasma compression. The plasma electron density depends on the initial conditions of the experiments. It was thus important to determine first the plasma flow characteristics before attempting any target irradiation. These data were needed for comparison with plasma characteristics after an irradiation of the investigated target. In fact, spectroscopic measurements performed during interactions of plasma streams with the investigated W samples showed many WI and WII spectral lines. The surface erosion was determined from mass losses of the irradiated samples. Changes on the surfaces of the irradiated samples were also investigated with an optical microscope and some sputtering and melting zones were observed.

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3 Nukleonika

3 2015

3 Paduch M.

3 Sadowski M. J.

3 Skladnik-Sadowska E.

3 Zaloga D. R.

3 Zielinska E.

2 Kubkowska M.

2 Kwiatkowski R.

2 Ladygina M. S.

2 Malinowski K.

1 Czaus K.

1 Garkusha I. E.

1 Gribkov V. A.

1 Kowalska-Strzeciwilk E.

1 Makhlaj V. A.

1 Miklaszewski R.

Search results

Recent ion measurements within the modified DPF-1000U facility

Comparison of optical spectra recorded during DPF-1000U plasma experiments with gas-puffing

Study of tungsten surface interaction with plasma streams at DPF-1000U