Wyniki wyszukiwania - BazTech

1

Damage and modification of materials produced by pulsed ion and plasma streams in Dense Plasma Focus device

Pimenov V. N., Demina E. V., Ivanov L. I., Gribkov V. A., Dubrovsky A. V., Ugaste U., Laas T., Scholz M., Miklaszewski R., Kolman B., Tartari A.

Nukleonika

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2008

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Vol. 53, No. 3

111-121

EN

The Dense Plasma Focus (DPF) devices PF-1000, PF-6 and PF-5M working with different gases and in dissimilar irradiation modes were used to carry out experimental investigations of irradiation of a number of materials by powerful pulsed ion and high-temperature plasma streams. The materials under test were designed for application in structural and functional components of thermonuclear fusion devices with magnetic (MPC) and inertial (IPC) plasma confinement, as well as for working chambers of plasma and accelerator devices. The main features of the materials are low-activation and radiation-resistant properties. On the basis of the investigations a significant progress was achieved in understanding of dynamics of high-energy nano- and micro-second pulsed streams in DPF from one side as well as on the mechanisms of their influence upon materials under irradiation from the other one. We demonstrated that this approach can be useful for certain tests of plasma-facing materials (e.g. W for MPC and stainless steels for IPC) and of structural (construction) elements of the above-mentioned devices subjected to pulsed high-energy radiation streams. The results obtained suggest also that DPF devices can be used in new pulse technologies for material treatment by means of powerful nanosecond and microsecond pulses of plasma and ion streams.

2

Development of diagnostic tools for Plasma Focus derived X-ray source

Angeli E., Bonifazzi C., Da Re A., Marziani M., Tartari A., Frignani M., Mannucci S., Mostacci D., Rocchi F., Sumini M.

Nukleonika

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2006

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Vol. 51, nr 1

15-20

EN

The energy spectra of X-rays generated by the impact of electron beams on high- and medium-Z targets following the pinch implosion of Plasma Focus (PF) devices are discussed in terms of the possible mechanisms of X-ray production following electron impact ionization. In addition, the temperature measurement of the PF inner electrode is reported and some results have been proved useful in order to optimize the device functionalities.

3

Preliminary study on X-ray source from Plasma Focus device for fast radiography

Da Re A., Mezzetti F., Tartari A., Verri G., Rapezzi L., Gribkov V. A.

Nukleonika

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2001

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Vol. 46, suppl. 1

123--125

EN

Plasma derived flash X-ray sources may find potential applications in medicine and industry. Notwithstanding, as is the case of Plasma Focus (PF) devices, their characterisation in term of photon energy, temporal and spatial beam stability is far to be considered satisfactory. In this work, a radiographic approach, which avoids the effects caused by the intrinsic instability of the pinch output of a PF machine, is proposed and an attenuation curve can be attained even in presence of Xray emission instability. Using two radiographic films for each shot exposition symmetrically positioned and collimated to the pinch region the mean energy of the photons in the X-ray beam are evaluated. The X-ray emission symmetry from the pinch region was then utilised to control the validity of the proposed methodology.

4

An internal standard for Fast Neutron Activation Analysis spectra obtained by means of Plasma Focus devices

Verri G., Tartari A., Rapezzi L., Mezzetti F., Gribkov V. A., Da Re A.

Nukleonika

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2001

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Vol. 46, suppl. 1

103--105

EN

The behaviour of Pb activation peaks, which appear in an X-ray spectrum of Fast Neutron Activation Analysis (FNAA) performed by means of a Plasma Focus (PF) neutron source and an NaI scintillator counter, has been studied. The PF device generates neutron bursts of different intensities. To know the exact neutron flux illuminating a sample during PF discharges an external neutron counter is usually used. The nature and behaviour of the indicated peaks suggest that one could use one of them as an internal standard for neutron production measurement instead of an external counter. This technique allows more reliable and accurate determinations of the presence of various elements.