Correlation between Plasma Dynamics and Emmision of Deuteron Beam, X-Rays and Neutrons in a Plasma Focus Discharge

Yamamoto, Toshikazu; Shimoda, Katsuji; Kobayashi, Kōji; Hirano, Koji

doi:10.1143/jjap.23.242

Cited by 13 publications

(6 citation statements)

References 22 publications

(11 reference statements)

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“…Figure 9 shows the TPS traces in type B. As seen in the figure, strong traces of N 1-3+ are observed with weak impurities of C + and O [1][2] . In contrast to type A, copper ions are not observed.…”

Section: Resultsmentioning

confidence: 90%

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Purity of nitrogen ion beams produced in a plasma focus

Takao

Honda

Kitamura

et al. 2003

Plasma Sources Sci. Technol.

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To improve the purity of ion beams produced in a plasma focus (PF), the dependence of the characteristics of the nitrogen ion beams on the shape of the anode was investigated. Two types of anodes, i.e. rod type (type A) and hollow type (type B) were used with a PF pre-filled with nitrogen gas. Thomson parabola spectrometer measurements showed the existence of a large amount of impurity ions, O 1-2+ , C + , and Cu 1-2+ , with nitrogen ions (N 1-3+ ) and the percentage of nitrogen ions is only 25% in type A. In contrast, in type B the impurity is extremely reduced and the percentage of nitrogen ions is enhanced to 91%. The maximum energies and power brightnesses of the nitrogen beams were evaluated to be 0.5 MeV and 0.23 GW cm −2 sr in type A and 1 MeV and 1.6 GW cm −2 sr in type B; hence, energy and brightness are also enhanced in type B. From x-ray pinhole images we see that strong electron irradiation occurs on the top of the anode in type A, whereas in type B, electron irradiation is weak and irradiation area is far from the pinch plasma. Hence, the impurity ions observed in type A are considered to be produced in the following process. Due to the strong irradiation of electrons on the anode top, the electrode and the absorbed gas on the electrode are vaporized, mixed with pinch plasma and accelerated with nitrogen ions.

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Section: Resultsmentioning

confidence: 90%

“…A plasma focus (PF) is known to produce high-energy, high current pulsed ion beams (PIB) having energies up to several MeV [1][2][3]. Since the obtainable ion current density is high, and by selecting the filling gas a wide variety of ion species can be produced, it can be considered as a potential PIB source.…”

Section: Introductionmentioning

confidence: 99%

Purity of nitrogen ion beams produced in a plasma focus

Takao

Honda

Kitamura

et al. 2003

Plasma Sources Sci. Technol.

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“…The generation of high energy particles that exceed the power-supply voltage has been reported in a conventional plasma focus device [6], and this observation is thought to be the appearance of a similar phenomenon.…”

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confidence: 82%

Hard X-Ray Radiation from a Z-Pinch with a Divergent Gas-Puff

Takasugi

Kiuchi

2007

Plasma and Fusion Research

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An experiment on a new type of z-pinch with divergent gas-puff was conducted for the realization of a point radiation source with high efficiency. X-ray radiation of energy 150 -200 keV that far exceeded the power-supply voltage was observed. The x-rays were radiated from the center of the anode surface, and the point radiation source was achieved. Since the energy transfer to a gas-puff z-pinch is efficient [1,2], and high temperature and high density plasma is easily achieved, it can be used as a soft x-ray and EUV light source. The high temperature plasma points (hot spots) produced are distributed on the center axis between the electrodes.On the other hand, the plasma converges to a single point in the plasma focus, and the point radiation source is formed. As the plasma flows axially after the conversion, dispersial to surrounding areas like the z-pinch is limited. However, previous plasma focus has the disadvantage of not obtaining a strong pinch easily. Since the device is filled with operating gas and initiated using the surface discharge from the insulator, the energy input is limited by the insulating material [3].The essence of the plasma focus is that the structure of the electrodes is coaxial, and not in plane symmetry. So the plasma produced is not axially uniform. The experiment using the z-pinch with the divergent gas-puff was conducted in order to realize the point radiation source with good efficiency using the advantage of both devices. It was understood during the process of the experiment that not only soft x-rays but also high energy x-rays would be radiated from the plasma, and the energy, the intensity, and the source of the x-rays were examined.The experiment was conducted using the SHOTGUN gas-puff z-pinch device at Nihon University (Fig. 1). The energy storage section of the device consists of a 30 kV 24 µF capacitor bank, and the maximum discharge current is 300 kA. The charged voltage of the bank was 25 kV in this experiment.The isolated gas distribution can be formed between the electrodes with a high-speed gas valve and an annular Laval nozzle mounted on the anode [4]. The gas was ejected parallel to the axis in the usual z-pinch experiment. Here the ejection angle of the gas was 10 • outward, and

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“…Most of the earlier experiments on ion beam emission were mainly carried out with a deuterium filling to investigate the general characteristic of the deuteron beam, the acceleration mechanism and inter-correlation to neutron production [28][29][30]. In 1985, Sadowski et al [31] observed the presence of a multi-spike structure in the ion beam signal, which is a common feature in plasma focus device of energy from 10 to 200 kJ.…”

Section: Introductionmentioning

confidence: 99%

Dynamics of ion beam emission in a low pressure plasma focus device

Lim¹,

Yap²,

Nee³

et al. 2021

Plasma Phys. Control. Fusion

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The plasma that accelerates and compresses in the formation of the pinch in dense plasma focus devices has been found to be an abundant source of multiple radiations like ion beams and x-rays. In this work, the ion beam and x-ray emissions from a 2.7 kJ (13.5 kV, 30 µF) plasma focus device operated at pressure below 1 mbar were investigated. The time profile of the ion beam emission was analysed from the simultaneously measured ion beam, soft and hard x-ray signals using biased ion collectors, BPX 65 silicon PIN diode and a scintillator-photomultiplier tube assembly. Time resolved analysis of the emissions revealed that the emission of the ion beam corresponded to several different pinching instances. Two components of the ion beam were identified. An ion beam of lower energy but higher intensity was emitted followed by an ion beam of higher energy but lower intensity in the first plasma pinch. The ion beam emitted from the first plasma pinch also has higher energy than subsequent plasma pinches. The emission was found to be associated with the amplitude of voltage spike. The results from ion beam and electron beams suggest that they were emitted by the same localized electric field induced in the pinched plasma. The strongest plasma focus discharge indicated by sharp voltage spike of high amplitude and highest ion beam energy were both observed at 0.2 mbar. The average energy of the ion beam obtained is (53 ± 13) keV. At this optimum condition, the ions beam with the highest energy also led to the highest hard x-ray emission.

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Correlation between Plasma Dynamics and Emmision of Deuteron Beam, X-Rays and Neutrons in a Plasma Focus Discharge

Cited by 13 publications

References 22 publications

Purity of nitrogen ion beams produced in a plasma focus

Purity of nitrogen ion beams produced in a plasma focus

Hard X-Ray Radiation from a Z-Pinch with a Divergent Gas-Puff

Dynamics of ion beam emission in a low pressure plasma focus device

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