Numerical experimentation on focusing time and neutron yield in GN1 plasma focus machine

2014 ◽  
Vol 32 ◽  
pp. 1460325 ◽  
Author(s):  
Arwinder Singh ◽  
Sing Lee ◽  
Sor Heoh Saw
Keyword(s):  
Plasma Focus ◽  
Neutron Yield ◽  
Experimental Results ◽  
Phase Model ◽  
Current Waveform ◽  
Plasma Dynamics ◽  
Model Code ◽  
Numerical Experimentation ◽  
Deuterium Gas ◽  
Current Trace

In this paper, we have shown how we have fitted Lee's six phase model code to analyze the current waveform of the GN1 plasma focus machine working in deuterium gas. The Lee's 6-phase model codes was later configured to work between 0.5 to 6 Torr and the results of both focusing time and neutron yield was than compared with the published experimental results. The final results indicate that Lee's code, gives realistic plasma dynamics and focus properties together with a realistic neutron yield for GN1 plasma focus, without the need of any adjustable parameters, needing only to fit the computed current trace to a measured current trace.

scholarly journals Comparison of Plasma Dynamics in Plasma Focus Devices PF1000 and PF400

2016 ◽  
Vol 3 (1) ◽  
pp. 55 ◽  
Author(s):  
Amir Shakya ◽  
Prakash Gautam ◽  
Raju Khanal
Keyword(s):  
Experimental Data ◽  
Plasma Focus ◽  
Numerical Experiments ◽  
Atomic Energy Commission ◽  
Total Current ◽  
Current Waveform ◽  
Lee Model Code ◽  
Plasma Dynamics ◽  
Model Code ◽  
Pinch Current

<p>In this work we have simulated two different sizes of plasma focus devices: PF400, a small sub-kJ plasma focus device in operation at the Atomic Energy Commission in Chile and PF1000, a 1 MJ device at the International Centre for Dense Magnetised Plasmas (ICDMP) in Warsaw, Poland. Our aim is to compare the plasma dynamics observed in two different sizes of the devices. We compare the experimentally obtained data with the data predicted from our numerical experiments using the Lee model code. It has been observed that the peak current of the total current waveform, pinch current calculated from total current, and neutron yield agree reasonably well with published experimental data, however, slight differences are found in other parameters.</p><p>Journal of Nepal Physical Society Vol.3(1) 2015: 55-59</p>

scholarly journals Correlation of measured neon soft X-ray pulses of the INTI plasma focus with the reflected shock phase at 12KV

2014 ◽  
Vol 32 ◽  
pp. 1460327
Author(s):  
Federico A. Roy ◽  
Perk Lin Chong ◽  
Sor Heoh Saw
Keyword(s):  
Plasma Focus ◽  
Energy Window ◽  
Current Waveform ◽  
Lee Model Code ◽  
X Ray ◽  
Model Code ◽  
Reflected Shock ◽  
Shock Phase ◽  
Time Histories ◽  
Pinch Phase

The six-phase Lee Model Code is used to fit the computed current waveform to the measured waveform of the INTI Plasma Focus (PF;2.2 kJ at 12 kV), a T2 PF device, operated as a source of Neon soft X-ray (SXR) with optimum yield around 2.5 - 3 Torr of neon. The characteristic He-like and H-like neon line SXR pulse is measured using a pair of SXR detectors with selected filters that, by subtraction, have a photon energy window of 900 to 1550 eV covering the region of the characteristic neon SXR lines. The aim of this paper is to investigate the correlation between the time histories of the measured Neon soft X-ray pulse and the reflected shock phase of the computed current waveform which has been fitted to the measured current waveform. Results shows that the characteristic neon SXR measured at 3.17 J with a pulse duration of 249 ns starts typically after the radial inward shock phase and increases in magnitude few ns before the pinch phase. It tails unto the first anomalous resistance, and decays at the second anomalous resistance.

scholarly journals Application of Lee Model Curve on Fitting of Discharge Current Curve of Plasma Focus Device

2021 ◽  
Vol 1 (1) ◽  
pp. 47-56
Author(s):  
Prakash Gautam
Keyword(s):  
Plasma Focus ◽  
Numerical Experiments ◽  
Electrical Circuit ◽  
Model Parameters ◽  
Lee Model Code ◽  
Lee Model ◽  
Model Code ◽  
Current Curve ◽  
Computer Based ◽  
Current Trace

A dense plasma focus is a table top machine producing a short-lived extremely popular plasma and cause fusion. Lee Model Code is a computer-based visual basic simulation package, which was successfully utilized in the plasma focus devices. The dynamics of plasma focus discharge is quite complicated, so to review and simplify the complication Lee Model couples electrical circuit with the plasma focus dynamics, radiation and therefore the thermodynamics. This enables us to simulate all of the gross focus properties. In this paper the numerical experiments are carried out to compute the current trace as a function of time for plasma focus (PF) device NX2. Results obtained by the numerical experiments are compared with the published laboratory measured data. This current fitting is completed to get the model parameters.

Calibration of Activation Counter by a 2.48 kJ Plasma Focus Device

2010 ◽  
Author(s):  
Sahar Rajabi Moghadam ◽  
Fereydoon Abbasi Davani ◽  
Babak Shirani Bidabadi
Keyword(s):  
Neutron Source ◽  
Plasma Focus ◽  
Neutron Yield ◽  
Plastic Scintillator ◽  
Plasma Focus Device ◽  
Removal Method ◽  
Deuterium Gas ◽  
Silver Activation Counter

A silver activation counter has been constructed by plastic scintillator plates along with silver foils for determination the neutron yield of a 2.48kJ plasma focus device, SBUPF1. This counter was calibrated by source removal method with an Am-Be 5 Ci neutron source which was placed above the anode of plasma focus device. Deuterium gas up to 8mbar pressure was injected to this device, and the neutron yield produced by pulsed D-D fusion of plasma focus device was measured by the counter. the neutron yield of SBUPF1 in 8mbar pressure was obtained 3.71±0.32×107 neutrons per shot. This result has relatively agreed with the neutron yield measured by silver activation Geiger counters.

Similarity theory and increased neutron yield in a plasma focus

1973 ◽  
Vol 13 (6) ◽  
pp. 929-934 ◽  
Author(s):  
V.S. Imshennik ◽  
N.V. Filippov ◽  
T.I. Filippova
Keyword(s):  
Plasma Focus ◽  
Neutron Yield ◽  
Similarity Theory

Numerical Prediction of Particulate Flow Over a Backward-Facing Step Followed by a Filter Medium

2012 ◽  
Author(s):  
A. K. Dange ◽  
K. C. Ravi ◽  
F. W. Chambers
Keyword(s):  
Porous Medium ◽  
Recirculation Zone ◽  
Stokes Number ◽  
Velocity Profiles ◽  
Experimental Results ◽  
Phase Model ◽  
Discrete Phase Model ◽  
Backward Facing Step ◽  
Zone Length ◽  
Discrete Phase

Flow in air filter housings often is characterized by separation upstream of the filter. The effect of the separation on the motion of particles and their distribution at the filter is important to filter performance. The current research investigates these effects by applying CFD modeling to turbulent particulate flows over a backward-facing step followed by a porous medium representing a filter. The two-dimensional step flow was selected as it is an archetype for separated flow with many studies in the literature. The flow examined has a step expansion ratio of 1:2, with an entrance length of 30 step heights to the step followed by a length of 60 step heights. Computations were performed at step Reynolds numbers of 6550 and 10,000 for the step without a porous medium and with the medium placed 4.25 and 6.75 step heights downstream of the step. The mesh was developed in ICEM CFD and modeling was done using the Fluent commercial CFD package. The carrier phase turbulence was modeled using the RNG k-epsilon model. The particles were modeled using the discrete phase model with dispersion modeled using stochastic tracking. The boundary conditions are uniform velocity at the inlet, no-slip at the walls, porous jump at the porous medium, and outflow at the outlet. The particle boundary condition is “reflect” at the walls and “trap” at the filter. The numerical results for the no filter case matched experimental results for recirculation zone length and velocity profiles at 3.75 and 6.25 step heights well. The computed velocity profiles at 3.75 step heights do not match experimental profiles for the filter at 4.25 step heights so well, though the results show a profound effect on the recirculation zone length, matching the experiments. Differences are attributed to different velocity profiles at the step. With the medium 6.75 step heights downstream, the effect on the recirculation zone is negligible, again matching experimental results. The discrete phase model tracks injected particles and provides results which are qualitatively similar to the literature. It is observed that particles with lower Stokes number, and thus lower momentum, tend to follow the flow and enter the recirculation zone while particles with higher Stokes number tend to move directly to the porous medium. When the filter is moved downstream to 6.75 step heights, the increased length of the recirculation zone results in more particles entering the recirculation zone. Results for monodispersed and polydispersed particles agree.

scholarly journals Experimental research of neutron yield and spectrum from deuterium gas-puff z-pinch on the GIT-12 generator at current above 2 MA

2017 ◽  
Vol 830 ◽  
pp. 012017
Author(s):  
R K Cherdizov ◽  
F I Fursov ◽  
V A Kokshenev ◽  
N E Kurmaev ◽  
A Yu Labetsky ◽  
...  
Keyword(s):  
Experimental Research ◽  
Neutron Yield ◽  
Deuterium Gas ◽  
Z Pinch
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