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Ion Beams and Plasma Streams- some results from numerical experiments-

Ion Beams and Plasma Streams- some results from numerical experiments-. S Lee & S H Saw INTI International University, 71800 Nilai, Malaysia Institute for Plasma Focus Studies, Chadstone VIC 3148 Australia e-email: leesing@optusnet.com.au ; sorheoh.saw@newinti.edu.my.

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Ion Beams and Plasma Streams- some results from numerical experiments-

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  1. Ion Beams and Plasma Streams- some results from numerical experiments- S Lee & S H Saw INTI International University, 71800 Nilai, Malaysia Institute for Plasma Focus Studies, Chadstone VIC 3148 Australia e-email: leesing@optusnet.com.au; sorheoh.saw@newinti.edu.my

  2. Scope of discussion Use of the Lee Model code to study scaling of deuteron beams for consideration of damage and materials, nano-materials modification and synthesis. Related scaling of Fast Plasma Stream and anode sputtered material

  3. Sequence of shadowgraphs of PF Pinch- M ShahidRafique PhD Thesis NTU/NIE Singapore 2000 Highest post-pinch axial shock waves speed ~50cm/us M500 Highest pre-pinch radial speed>25cm/us M250

  4. Much later…Sequence of shadowgraphics of post-pinch copper jetS Lee et al J Fiz Mal 6, 33 (1985) Slow Copper plasma jet 2cm/us M20

  5. Plasma Focus Pinch

  6. Emissions from the PF Pinch region +Mach500 Plasma stream +Mach20 anode material jet

  7. Comparing large and small PF’s- Dimensions and lifetimes- putting shadowgraphs side-by-side, same scale Anode radius 1 cm 11.6 cm Pinch Radius: 1mm 12mm Pinch length: 8mm 90mm Lifetime ~10ns order of ~100 ns

  8. Flux out of Plasma Focus Charged particle beams Neutron emission when operating with D Radiation including Bremsstrahlung, line radiation, SXR and HXR Plasma stream Anode sputtered material

  9. Modelling the flux-reporting preliminary work Ion beam flux Preliminary work shows the quantity ion beam flux (Fib ions per m2 per sec) x pulse length (t sec) which has the units of number of ions per m2 (per shot) is: Fibt = Cn Ipinch2zp[ln(b/rp)]/ (prp2 U1/2) All SI units: calibration constant Cn =8.5x108 ; model was calibrated against an experimental point at 0.5MA Ipinch=pinch current zp=pinch length b=outer electrode, cathode rp=pinch radius U=beam energy in eV where in this model U=3x (dynamic induced voltage)

  10. Numerical Expt for PF1000 based on following fitted parameters:L0=33 nH, C0=1332 uF, b=16 cm, a= 11.6 cm, z0=60 cm r0=6.3 mWfm=0.14, fc=0.7, fmr=0.35, fcr=0.7V0=27 kV, P0= 3.5 Torr MW=4, A=1, At=2 for deuterium Results are extracted from dataline after shot: Yn=1.16x1011 neutrons, ni=3.87x1023 per m2, Ipinch=8.63x105 A, zp=0.188 m, b/rp=16 cm/2.23 cm, ln(b/rp)=1.97, U=3Vmax=3x4.21x104 =1.263x105 V; fusion x-section σ =0.0238barns = 2.38x10-30 m2.

  11. Numerical Expt for INTI PF based on following fitted parameters:L0=110 nH, C0=30 uF, b=3.2 cm, a= 0.95 cm, z0=16 cm r0=12 mWfm=0.073, fc=0.7, fmr=0.16, fcr=0.7V0=15 kV, P0= 3Torr MW=4, A=1, At=2 for deuterium Results are extracted from dataline after shot: Yn=1.14x107 neutrons, ni=3.5x1023 per m2, Ipinch=1.22x105 A, zp=0.014 m, b/rp=3.2cm/0.12 cm, ln(b/rp)=3.28; U=3Vmax=3x2.52x104 =0.756x105 V; fusion x-section σ =0.0112barns=1.12x10-30 m2.

  12. From the above; estimate ions/m2 per shot For PF1000 (at 500 kJ) we obtained Jbt =4.3x1020 ions/m2 per shot=4.3x1016 ions/cm2 per shot at 126 keV (~1kJ/cm2; 109 W/cm2 if pulse of 1 ms) For INTI PF (at 3 kJ) we obtained Jbt =4.7x1020 ions/m2 per shot =4.7x1016 ions/cm2 per shot at 76 keV Quantity Jbt is the same for small and big PF

  13. Number of Ions in beam Taking pinch radius as effective area for beam For PF1000 rp=2.23 cm (model computation) Thus number of ions per pulse=6.7x1017 at effective energy of 126 keV(14kJ 3% E0) For INTI PF rp=0.12 cm (model computation) Thus number of ions per pulse=2.1x1015 at effective energy of 76 keV Number of ions per pulse is 300 x higher for PF1000 compared to INTI PF(26J 1% E0)

  14. We intend to refine these computation We have the neutron yield for each of the devices- numerical expts have been compared to actual measurements and found to agree-typically 1011 per shot for PF1000 We will compute plasma stream energy by looking at the quantity EINP (work done by magnetic piston as % of stored energy) –typically 13% E0 (65kJ) for PF1000; and 9% E0 (270 J) for INTI PF These will be carried out in the next period.

  15. Latest development Modelling Ion beam fluence Post focus axial shock waves Plasma streams Anode sputtered material

  16. Ion beam post-pinch plasma stream calculations Some preliminary Results- INTI IU-IAEA collaboration

  17. Ion Fluence as function of E0 2-6x1020 ions/m2

  18. Average Ion Energy as function of E0 50-300 keV

  19. Beam duration as function of E0

  20. Beam Duration as function of Anode radius

  21. Beam Energy as function of E0 ~3%

  22. FIB Damage Factor ~ 1-5x1010 Wm-2s0.5ti

  23. Fast Plasma Stream Energy exiting pinch ~ 5-10%

  24. Concluding Summary The ion fluence , 2-6x1020 ions/m2 average ion energy 40-250 keV and beam damage factor 2x1010 Wm-2s0.5 are found to be independent of storage energy being relatively constant over the range of devices, from kJ to MJ. The beam size (on exit) and duration increase with storage energy, primarily as a function of anode radius. The beam energy increases with storage energy 1-3% ; as does the fast plasma stream energy exiting the pinch 5-10% . Anode sputtered materials, slow jet typically 1-3%.

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