Neutron Scaling Laws from Numerical Experiments

Lee, S.; Saw, S. H.

doi:10.1007/s10894-008-9132-7

Cited by 87 publications

(73 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The code has been used extensively in several machines including UNU/ICTP PFF [2,7,8,10,11,[15][16][17], NX2 [9,12,18], and NX1 [18,19] and has been adapted for the Filippov-type plasma focus DENA [20]. A recent development is the inclusion of the neutron yield Y n using a beam-target mechanism [21][22][23][24][25], incorporated in recent versions [26,27] of the code (versions later than RADPFV5.13), resulting in realistic Y n scaling with I pinch [21,22]. The versatility and utility of the model are demonstrated in its clear distinction of I pinch from I peak [28] and the recent uncovering of a plasma focus pinch current limitation effect [23,24,29] as static inductance is reduced towards zero.…”

Section: Open Accessmentioning

confidence: 99%

“…The versatility and utility of the model are demonstrated in its clear distinction of I pinch from I peak [28] and the recent uncovering of a plasma focus pinch current limitation effect [23,24,29] as static inductance is reduced towards zero. Extensive numerical experiments had been carried out systematically resulting in the uncovering of neutron [21][22][30][31][32][33] and SXR [30][31][32][33][34][35][36][37] scaling laws over a wider range of energies and currents than attempted before. The numerical experiments also gave insight into the nature and cause of 'neutron saturation [31,33,38].…”

Section: Open Accessmentioning

confidence: 99%

“…The beam interacts with the hot dense plasma of the focus pinch column to produce the fusion neutrons. The beam-target yield is derived [21][22][23][24]26] as:…”

Section: Computation Of Neutron Yield-describing the Beam-target Mechmentioning

confidence: 99%

“…A reasonably good fit of the computed neutron yields to the measured published neutron yields at energy levels from sub-kJ to near MJ was obtained when the multiple of 3 was used; with poor agreement for most of the data points when for example a multiple of 1 or 2 or 4 or 5 was used. The model uses a value of C n = 2.7 × 10 7 obtained by calibrating the yield [21][22][23]26], at an experimental point of 0.5 MA. The thermonuclear component is also computed in every case and it is found that this component is negligible when compared with the beam-target component.…”

Section: Computation Of Neutron Yield-describing the Beam-target Mechmentioning

confidence: 99%

See 3 more Smart Citations

Numerical Experiments Providing New Insights into Plasma Focus Fusion Devices

Lee

Saw

2010

Energies

View full text Add to dashboard Cite

Recent extensive and systematic numerical experiments have uncovered new insights into plasma focus fusion devices including the following: (1) a plasma current limitation effect, as device static inductance is reduced towards very small values; (2) scaling laws of neutron yield and soft x-ray yield as functions of storage energies and currents; (3) a global scaling law for neutron yield as a function of storage energy combining experimental and numerical data showing that scaling deterioration has probably been interpreted as neutron 'saturation'; and (4) a fundamental cause of neutron 'saturation'. The ground-breaking insights thus gained may completely change the directions of plasma focus fusion research.

show abstract

Section: Open Accessmentioning

confidence: 99%

Section: Open Accessmentioning

confidence: 99%

“…The beam interacts with the hot dense plasma of the focus pinch column to produce the fusion neutrons. The beam-target yield is derived [21][22][23][24]26] as:…”

Section: Computation Of Neutron Yield-describing the Beam-target Mechmentioning

confidence: 99%

Section: Computation Of Neutron Yield-describing the Beam-target Mechmentioning

confidence: 99%

See 2 more Smart Citations

Numerical Experiments Providing New Insights into Plasma Focus Fusion Devices

Lee

Saw

2010

Energies

View full text Add to dashboard Cite

show abstract

“…The code has been used extensively in several machines including UNU/ICTP PFF [2]- [6], [14], [15], [19], NX2 [7], [16], [20], and NX1 [20], [21] and has been adapted for the Filippov-type plasma focus DENA [22]. A recent development is the inclusion of the neutron yield Y n using a beam-target mechanism [23]- [27], incorporated in recent versions [8] of the code (versions later than RADPFV5.13), resulting in realistic Y n scaling with I pinch [23], [24]. The versatility and utility of the model are demonstrated in its clear distinction of I pinch from I peak [28] and the recent uncovering of a plasma focus pinch current limitation effect [25], [26].…”

Section: Lee Model Code Incorporating Line Radiationmentioning

confidence: 99%

Optimizing UNU/ICTP PFF Plasma Focus for Neon Soft X-ray Operation

Saw¹,

Lee

Rawat

et al. 2009

IEEE Trans. Plasma Sci.

View full text Add to dashboard Cite

Abstract-The United Nations University/International Centre for Theoretical Physics Plasma Focus Facility (UNU/ICTP PFF), a 3.3-kJ plasma focus, was designed for operation in deuterium with a speed factor S such that the axial run-down time matches the current rise time at an end axial speed of nearly 10 cm/μs. For operation in neon, we first consider that a focus pinch temperature between 200 and 500 eV may be suitable for a good yield of neon soft X-rays, which corresponds to an end axial speed of 6-7 cm/μs. On this basis, for operation in neon, the standard UNU/ICTP PFF needs to have its anode length z 0 reduced by some 30%-40% to maintain the time matching. Numerical experiments using the Lee model code are carried out to determine the optimum configuration of the electrodes for the UNU/ICTP PFF capacitor system. The results show that an even more drastic shortening of anode length z 0 is required, from the original 16 to 7 cm, at the same time, increasing the anode radius "a" from 0.95 to 1.2 cm, to obtain an optimum yield of Y sxr = 9.5 J. This represents a two-to threefold increase in the Y sxr from that computed for the standard UNU/ICTP PFF.Index Terms-Dense plasma focus, neon plasma, numerical experiments, soft X-ray (SXR) source.

show abstract

Experimental and numerical fitting of model parameters versus the gas pressure using six phase radiative Lee model in AECS PF‐1, 2 and INTI PF for nitrogen, argon, and neon gases

Al‐Hawat

Akel

Saw³

et al. 2020

Contributions to Plasma Physics

View full text Add to dashboard Cite

Atomic energy commission of syria (AECS) PF‐1, 2 devices were operated in N2 and Ar gases at pressures varied between 0.1–1 mbar and applied voltage of 15 kV on the capacitors bank with capacitance of 25 μF. The voltage, current, and current derivative curves were digitally recorded by Ohmic voltage divider and two Rogowskii coils; one with a big number of turns for current and the other one with a low number of turns for the current derivative. Also, the current curve for the discharge as LCR circuit was recorded to calibrate the current measurement. By integrating the current derivative in time and using the curve of calibrated current, the current curve free of noise has been established. By inserting the geometrical and electrical parameters of two AECS PF‐1, 2 devices, the working gas pressure and the kind of the gas into six phase model which describes the instability in the plasma, and adding the anomalous resistance as a term in the current and voltage equations in the model; the computed curves for voltage and current were found and compared with the obtained experimental curves at the same conditions taking into account the readjustment of model parameters fm, fc, fmr, and fcr until getting a good fitting between the measured and computed currents. This fitting has proved the validity of six phase Lee model and its ability to give a description of plasma focus in the radial phase stage (which consists now of four subradial phases: radial inward shock, radial reflected shock, the pinch phase, and after that the instability phase), which is followed by the expanded phase of plasma focus. In parallel to our work, similar efforts were made on the INTI PF device in Ne; the validity of six phase Lee model was proved by getting a proper fitting between the measured and computed currents under the operational conditions. Moreover, the equivalent resistances and time scales of the anomalous resistance phases were obtained by this method; also, the ratios for PF device classification into two types according to the static inductance of the PF system were determined for N2 and Ar as working gases in AECS‐PF1, 2.

show abstract

Neutron Scaling Laws from Numerical Experiments

Cited by 87 publications

References 4 publications

Numerical Experiments Providing New Insights into Plasma Focus Fusion Devices

Numerical Experiments Providing New Insights into Plasma Focus Fusion Devices

Optimizing UNU/ICTP PFF Plasma Focus for Neon Soft X-ray Operation

Experimental and numerical fitting of model parameters versus the gas pressure using six phase radiative Lee model in AECS PF‐1, 2 and INTI PF for nitrogen, argon, and neon gases

Contact Info

Product

Resources

About