Presentation on theme: "From Electric Birth through Micro-nova to"— Presentation transcript:
1 From Electric Birth through Micro-nova to Siam Physics Congress SPC2013 Thai Physics Society on the Road to ASEAN Community March 2013From Electric Birth through Micro-nova toStreaming Demise of the Plasma Focus-Knowledge and ApplicationsS Lee1,2,3 & S H Saw1,21INTI International University, Nilai, Malaysia2Institute for Plasma Focus Studies, Chadstone, VIC 3148, Australia3University of Malaya, Kuala Lumpur, Malaysia;
2 Introductory: What is a Plasma? Matter heated to high temperatures becomes a PlasmaFour States of MatterSOLID LIQUID GAS PLASMA
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 ProcessDynamic 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 pinchesA 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 powersE.g. SXR emission peaks at 109 W over nsIn 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)
11 Axial Accelaration Phase The Plasma Dynamics in FocusRadial PhaseHV30 mF, 15 kVAxial Accelaration PhaseInverse 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 UPF Applications : e.g. PF Isotope production PF developmentEnhancing Polypropylene-polyester/ for medical applicationsCotton Composites LaminationRattachat, Mongkolnavin, et alSingapore: PF Radiation:NTU/NIEMalaysia: INTI IU- IPFSU Malaya : PF Studies PF Numerical ExptsUTMPF 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 FocusRadial PhaseHV30 mF, 15 kVAxial Accelaration PhaseInverse Pinch Phase
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 jetThe 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
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 onlyBig Plasma Focus
26 Comparing large & small PF’s- Dimensions & lifetimes- putting shadowgraphs of pinch side-by-side, same scaleAnode radius 1 cm cmPinch Radius: 1mm mmPinch length: 8mm mmLifetime ~10ns order of ~200 ns
27 Comparison (Scaling) - 1/2 Important machine properties: UNU ICTP PFF PF1000E kJ at 15 kV kJ at 30kVI 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 plasmaLifetime of plasmaThese two properties together with the above two determine total yield.
29 Basic information from simple measurements Speed is easily measured; e.gFrom current waveform16 cm traversed in 2.7 usAv speed=6 cm/usForm factor= 1.6Peak speed ~ 10 cm/usAt 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 D2Axial speed [measured] cm/usRadial speed cm/usTemperature x x KReflected S x x K After RS comes pinch phase which may increase T a little more in each caseComparative 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’ densityShock density ratio=4 (for high temperature deuterium)RS density ratio=3 timesOn-axis density ratio=12Initial at 3 torr n=2x1023 atoms m-3RS density ni=2.4x1024 m-3 or 2.4x1018 per ccFurther 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 torrSimilar shock processesSimilar 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 speedsConclusion: all PF’s:Same T, hence same energy (density) per unit masssame n, hence same energy (density) per unit volumeHence same radiation intensity
35 Next question: How does yield vary? Yield is Intensity x Volume x LifetimeYield~ radius4Or ~ 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 electronsMicro-machiningSurface modification and alloying, deposition of advanced materials: superconducting films, fullerenes, DLC films, TiN, ZrAlON, nanostructured magnetic e.g. CoPt thin filmsSurface damage for materials testing in high-radiation and energy flux environment
37 Applications list/2 Diagnostic systems of commercial/industrial value: CCD-based imagingmulti-frame ns laser shadowgraphypin-hole and aperture coded imaging systemsneutron detectors, neutron activation, gamma ray spectroscopydiamond and diode x-ray spectrometervacuum uv spectrometerFaraday cupsmega-amp current measurementpulsed magnetic field measurementtemplated SXR spectrometrywater-window radiation for biological applications
38 Applications list/3 Pulsed power technology: capacitor discharge Pulsed power for plasma, optical and lighting systemstriggering technologyrepetitive systemscircuit manipulation technology such as current-steps for enhancing performance and compressionspowerful multi-radiation sources with applications in materials and medical applications
39 Applications list/4Plasma 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 sourceless than 1 mm source diameterwavelength range of nmfrom industrial throughput considerations, output powers in excess of 1 kW (into 4p)
47 4. Thin film deposition, fabrication Materials modification using Plasma Focus Ion BeamFor 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) magneticmaterialsmechanism of nano-phase material synthesiseffect of various deposition parameters on themorphology and size distribution of deposited nano-phase materialTo reduce the phase transition temperatures
50 Applications for nano-particles DataStorageMedical ImagingDrug DeliveryCancel Therapy
51 100nm FeCo agglomerates deposited NX2 set-up for depositing thin films; deposited thin filmswith 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 withthe proven most effective numerical experiment system Lee Model codewith 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 trainingand research system will be updated as a 1 kJ system
54 6b. The proven most effective and comprehensive Model code Firmly grounded in PhysicsConnected to realityFrom birth to death of the PFUseful and comprehensive outputsDiagnostic reference-many properties, design, scaling & scaling laws, insights & innovations
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 deathRadiation products of the PF pinchResearch on some applications- showing ‘products’ as achieved (varying stages) and visualised