1. From Electric Birth through Micro-nova to
Siam Physics Congress SPC2013 Thai Physics Society on the Road to ASEAN Community March 2013
From Electric Birth through Micro-nova to
Streaming Demise of the Plasma Focus-
Knowledge and Applications
S Lee1,2,3 & S H Saw1,2
1INTI International University, Nilai, Malaysia
2Institute for Plasma Focus Studies, Chadstone, VIC 3148, Australia
3University of Malaya, Kuala Lumpur, Malaysia ;

2. Introductory: What is a Plasma?
Matter heated to high temperatures becomes a Plasma
Four States of Matter
SOLID LIQUID GAS PLASMA

3. One method: electrical discharge through gases.

4. Lightning: Electric discharge (e. g
Lightning: Electric discharge (e.g. 20kA) between earth & clouds heats up the air in the discharge channels to high temperatures (30,000 K) producing air plasmas

5. Current I & self-field B produces force JXB pointing everywhere radially inwards- Pinches column from initial radius r0 to final radius rm.

6. Pinching Process
Dynamic pinching process requires current to rise very rapidly, typically in under 0.1 microsec in order to have a sufficiently hot and dense pinch.
Super-fast, super-dense pinch; requires special MA fast-rise (nanosec) pulsed-lines; Disadvantages: conversion losses & cost of high technology pulse-shaping line, additional to the capacitor.

7. Superior method for super-dense-hot pinch: plasma focus (PF)
The PF produces superior densities and temperatures. (easily a million C up to tens of millions C)
2-Phase mechanism of plasma production does away with the extra layer of technology required by fast pinches
A simple capacitor discharge is sufficient to power the plasma focus.

8. High Power Radiation from PF
Powerful bursts of x-rays, ion & electron beams, & EM radiation (>10 gigaW)
Intense radiation burst, extremely high powers
E.g. SXR emission peaks at 109 W over ns
In deuterium, fusion neutrons also emitted

9. : Plasma Focus independently invented, early 1960’s by
N V Filippov
(4th from left)
J W Mather
(3rd from left, front row)

10. INTI PF- 3 kJ Plasma Focus

11. Axial Accelaration Phase
The Plasma Dynamics in Focus
Radial Phase HV
30 mF, 15 kV
Axial Accelaration Phase
Inverse Pinch Phase

12. 1972: UM plasma focus discharge in Two Asian Firsts up to that time: Achieved 1.9 MA pulsed discharge Detected and measured Plasma D-D fusion neutrons-

13. Today- PF Collaboration among ASEAN Institutions
Thailand:
Chulalongkorn University Thammasat University: Prince of Songla U
PF Applications : e.g. PF Isotope production PF development
Enhancing Polypropylene-polyester/ for medical applications
Cotton Composites Lamination
Rattachat, Mongkolnavin, et al
Singapore: PF Radiation:
NTU/NIE
Malaysia: INTI IU- IPFS
U Malaya : PF Studies PF Numerical Expts
UTM
PF Applications e.g. Nano-materials;
Radiative Cooling & Collapse

14. Photo of the INTI PF pinch (P Lee) using filter technique to show the pinch region & the jet

15. Axial Accelaration Phase
The Plasma Dynamics in Focus
Radial Phase HV
30 mF, 15 kV
Axial Accelaration Phase
Inverse Pinch Phase

16. Sub Systems of the Plasma Focus

17. Highest post-pinch axial shock waves speed ~50cm/us M500
Shadowgraphs of PF Pinch- (Micro-nova) M Shahid Rafique PhD Thesis NTU/NIE Singapore 2000
Highest post-pinch axial shock waves speed ~50cm/us M500
Highest pre-pinch radial speed>25cm/us M250

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

19. Emissions from the PF Pinch region
+Mach500 Plasma stream
+Mach20 anode material jet
The ion beams, plasma streams and anode- sputtered jets are used for advanced materials modification and fabrication, including nano-materials; and for studies of materials damage

20. A Small Plasma Focus Laboratory

21. The Parts for the Plasma Focus

22. The Anode and the Cathode

23. Diagnostics

24. Basic Measurements- Current: using pick-up coil Voltage: resistive voltage divider

25. Scaling Properties 1 m 3 kJ machine Small Plasma Focus
1000 kJ chamber only
Big Plasma Focus

26. Comparing large & small PF’s- Dimensions & lifetimes- putting shadowgraphs of pinch side-by-side, same scale
Anode radius 1 cm cm
Pinch Radius: 1mm mm
Pinch length: 8mm mm
Lifetime ~10ns order of ~200 ns

27. Comparison (Scaling) - 1/2 Important machine properties:
UNU ICTP PFF PF1000
E kJ at 15 kV kJ at 30kV
I kA 2MA
‘a’ cm cm

28. Comparison (Scaling) - 2/2 Important Compressed Plasma Properties
Density of plasma same!!
Temperature of plasma same!!
These two properties determine radiation intensity energy radiated per unit volume per unit lifetime of plasma)
Size of plasma
Lifetime of plasma
These two properties together with the above two determine total yield.

29. Basic information from simple measurements
Speed is easily measured; e.g
From current waveform
16 cm traversed in 2.7 us
Av speed=6 cm/us
Form factor= 1.6
Peak speed ~ 10 cm/us
At end of axial phase

30. Estimate Temperature from speeds
Speed gives KE.
Shock Waves convert half of KE to Thermal Energy:
T~q2 ; where q is the shock speed ~ speed of current sheet.
For D2: T=2.3x10-5q2 K q in m/s
(from strong shock-jump conservation equations)

31. Axial speed 10 [measured] 12 cm/us Radial speed 25 20 cm/us
Compare Temperatures: speeds easily measured; simply from a current waveform; from speeds, temperature may be computed.
UNU ICTP PFF PF D2
Axial speed [measured] cm/us
Radial speed cm/us
Temperature x x K
Reflected S x x K After RS comes pinch phase which may increase T a little more in each case
Comparative T: about same; several million K

32. Compare Number Density – 1/2
During shock propagation phase, density is controlled by the initial density and by the shock-’jump’ density
Shock density ratio=4 (for high temperature deuterium)
RS density ratio=3 times
On-axis density ratio=12
Initial at 3 torr n=2x1023 atoms m-3
RS density ni=2.4x1024 m-3 or 2.4x1018 per cc
Further compression at pinch; raises number density higher typically to 1019 per cc.

33. Compare Number Density – 2/2
Big or small PF: initial density small range of several torr
Similar shock processes
Similar final density

34. Big PF and small PF Same density, same temperature
Over a range of PFs smallest 0.1J to largest 1 MJ; over the remarkable range of 7 orders of magnitude- same initial pressure, same speeds
Conclusion: all PF’s:
Same T, hence same energy (density) per unit mass
same n, hence same energy (density) per unit volume
Hence same radiation intensity

35. Next question: How does yield vary?
Yield is Intensity x Volume x Lifetime
Yield~ radius4
Or ~ current4

36. Our research towards applications
Some plasma focus applications experimented with to various levels of success.
Microelectronics lithography towards nano-scale using focus SXR, EUV and electrons
Micro-machining
Surface modification and alloying, deposition of advanced materials: superconducting films, fullerenes, DLC films, TiN, ZrAlON, nanostructured magnetic e.g. CoPt thin films
Surface damage for materials testing in high-radiation and energy flux environment

37. Applications list/2 Diagnostic systems of commercial/industrial value:
CCD-based imaging
multi-frame ns laser shadowgraphy
pin-hole and aperture coded imaging systems
neutron detectors, neutron activation, gamma ray spectroscopy
diamond and diode x-ray spectrometer
vacuum uv spectrometer
Faraday cups
mega-amp current measurement
pulsed magnetic field measurement
templated SXR spectrometry
water-window radiation for biological applications

38. Applications list/3 Pulsed power technology: capacitor discharge
Pulsed power for plasma, optical and lighting systems
triggering technology
repetitive systems
circuit manipulation technology such as current-steps for enhancing performance and compressions
powerful multi-radiation sources with applications in materials and medical applications

39. Applications list/4
Plasma focus design; complete package integrating hardware, diagnostics and software.
Fusion technology and fusion education, related to plasma focus training courses

40. Applications: SXR Lithography
As linewidths in microelectronics reduces towards 0.1 microns, SXR Lithography is set to replace optical lithography.
Baseline requirements, point SXR source
less than 1 mm source diameter
wavelength range of nm
from industrial throughput considerations, output powers in excess of 1 kW (into 4p)

41. Applications:
some ‘products’

42. 1. 300J portable (25 kg); 106 neutrons per shot fusion device

43. 2. SXR lithography using NX2 in neon

44. PF SXR Schematic for Microlithography1 2 3 4 5 6 7 8 9 10
PF SXR Schematic for Microlithography
1 - anode
2 - cathode
3 - SXR point source
4 - x-rays
5 - electron beam
deflection magnets
6 - shock wave shield
7 - Be window
8 - x-ray mask
9 - x-ray resist
10 - substrate

45. Lines transferred using NX2 SXR
X-ray masks in Ni & Au
SEM Pictures of transfers in AZPN114 using NX2 SXR

46. 3. X-ray Micromachining

47. 4. Thin film deposition, fabrication
Materials modification using Plasma Focus Ion Beam
For plasma processing of thin film materials on different substrates with different phase changes.

48. Applications: depositing Chromium and TiN- M Ghoranneviss

49. 5. Applications: Nanoparticles synthesis R S Rawat et al
Synthesize nano-phase (nano-particles,nano-clusters and nano-composites) magneticmaterials
mechanism of nano-phase material synthesis
effect of various deposition parameters on themorphology and size distribution of deposited nano-phase material
To reduce the phase transition temperatures

50. Applications for nano-particles
DataStorage
Medical Imaging
Drug Delivery
Cancel Therapy

51. 100nm FeCo agglomerates deposited
NX2 set-up for depositing thin films; deposited thin films
with consisting of 20nm particles

52. the proven most effective hardware system of the UNU/ICTP PFF with
6. Developing the most powerful training and research system for the dawning of the Fusion Age.
Integrate:
the proven most effective hardware system of the UNU/ICTP PFF with
the proven most effective numerical experiment system Lee Model code
with emphasis on dynamics, radiation and materials applications.

53. 6a. The proven most effective 3 kJ PF system.
The trolley based UNU/ICTP PFF 3 kJ plasma focus training
and research system will be updated as a 1 kJ system

54. 6b. The proven most effective and comprehensive Model code
Firmly grounded in Physics
Connected to reality
From birth to death of the PF
Useful and comprehensive outputs
Diagnostic reference-many properties, design, scaling & scaling laws, insights & innovations

55. Our Radiative Plasma Focus Code

56. 6c. The proven tradition and spirit of collaboration

57. Conclusion What is a plasma? Plasma focus and its pinch
The Pinch and the streaming death
Radiation products of the PF pinch
Research on some applications- showing ‘products’ as achieved (varying stages) and visualised

58. THANK YOU
Profound
Simple
Plasma Focus