Soft x-ray emission from a small plasma focus operated in deuterium

Abstract

Using composite anodes in a 3 kJ plasma focus device operated in deuterium, peak axial sheath velocities up to 15 cm µs −1 are achieved. The temporal characteristics of the soft x-ray emission are investigated by means of filtered PIN diodes. Correlations with hard-x-ray and neutron emission as well as with electrical parameters of the discharge are performed. Two distinct operation regimes are identified regardless of the shape of the anode. Various scaling laws of the soft x-ray production are investigated. We propose a new scaling law for the soft x-ray yield.

Plasma focus ion beam fluence and flux—For various gases

“…16) and used in the design and interpretation of experiments. [17][18][19] An improved 5-phase code 2 incorporating finite small disturbance speed, 20 radiation and radiation-coupled dynamics was used, [21][22][23] and was web-published 24 in 2000. Plasma self-absorption was included 24 in 2007.…”

Comparison of Measured Soft X-Ray Yield Versus Pressure for NX1 and NX2 Plasma Focus Devices Against Computed Values Using Lee Model Code

“…It has also been used in other machines for their design and interpretation including ultra-miniature pinch PF discharge operating at 0.1 J nano-focus [30]. Information obtained includes axial and radial dynamics [13,31,32], SXR emission characteristics and yield [7,17,18,[33][34][35][36], design of machines [12, 13, 17, 18, 32-34, 36, 37], optimization of machines [13,17,18,31,33,38] together with the adaptation of the Filippov-type DENA [26]. Plasma focus SXR yield calculations [7,25,[34][35][36][37]40], pinch current and SXR yield limitations [6,39], optimization of SXR yield [7,[34][35][36][37], radiative collapse and cooling [41,42], current stepped PF [43], PF neutron yield calculations [44,45], current and neutron yield limitations [6,46], neutron saturation [47,48] and extraction of diagnostic data [49][50][51]…”

“…Plasma focus SXR yield calculations [7,25,[34][35][36][37]40], pinch current and SXR yield limitations [6,39], optimization of SXR yield [7,[34][35][36][37], radiative collapse and cooling [41,42], current stepped PF [43], PF neutron yield calculations [44,45], current and neutron yield limitations [6,46], neutron saturation [47,48] and extraction of diagnostic data [49][50][51][52] and the anomalous resistance phase (RAN) data [53] from the current signals have been studied applying the code [54,55]. Speedenhanced PF [32] was facilitated. The inclusion of the neutron yield, Y n , using beam target mechanism [44,[54][55][56] is one the great step in the development, incorporated in the versions [54,55] of the code (later than RADPF5.13), resulting in realistic Y n scaling with I pinch [44,47,48].…”

Study of the electrode material and insulator length effect on high-energy X-rays emitted by a 4-kJ plasma focus device

“…The composi tion of the gas and filling pressure has the strongest influence on the characteristic X ray emission. The scaling law for the X ray output Y x as a function of the peak discharge current I p and the pinch radius r p can be written empirically as [7]. Correlation between the pinch dynamics and neu tron and X ray emission from a megajoule plasma focus device were studied by Sholtz et al [8].…”

“…Lee et al [12] studied the HXR spectrum of a plasma focus. Serban and Lee [7] investigated tem poral characteristics of X ray emission by means of fil tered PIN diodes. They also showed that Y x is equiva lent to , where is the axial speed of current sheath.…”