From Electric Birth through Micro-nova to Siam Physics Congress SPC2013 Thai Physics Society on the Road to ASEAN Community 21-23 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, 71800 Nilai, Malaysia 2Institute for Plasma Focus Studies, Chadstone, VIC 3148, Australia 3University of Malaya, Kuala Lumpur, Malaysia e-mail:; leesing@optusnet.com.au; sorheoh.saw@newinti.edu.my

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

One method: electrical discharge through gases.

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

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

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.

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.

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

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

INTI PF- 3 kJ Plasma Focus

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

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-

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

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

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

Sub Systems of the Plasma Focus

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

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

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

A Small Plasma Focus Laboratory

The Parts for the Plasma Focus

The Anode and the Cathode

Diagnostics

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

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

Comparing large & small PF’s- Dimensions & lifetimes- putting shadowgraphs of pinch side-by-side, same scale Anode radius 1 cm 11.6 cm Pinch Radius: 1mm 12mm Pinch length: 8mm 90mm Lifetime ~10ns order of ~200 ns

Comparison (Scaling) - 1/2 Important machine properties: UNU ICTP PFF PF1000 E0 3kJ at 15 kV 600kJ at 30kV I0 170 kA 2MA ‘a’ 1 cm 11.6 cm

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.

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

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)

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 PF1000 D2 Axial speed 10 [measured] 12 cm/us Radial speed 25 20 cm/us Temperature 1.5x106 1x106 K Reflected S 3x106 2x106 K After RS comes pinch phase which may increase T a little more in each case Comparative T: about same; several million K

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.

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

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

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

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

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

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

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

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 0.8-1.4 nm from industrial throughput considerations, output powers in excess of 1 kW (into 4p)

Applications: some ‘products’

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

2. SXR lithography using NX2 in neon

PF SXR Schematic for Microlithography 1 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

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

3. X-ray Micromachining

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.

Applications: depositing Chromium and TiN- M Ghoranneviss

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

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

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

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.

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

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

Our Radiative Plasma Focus Code

6c. The proven tradition and spirit of collaboration

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

THANK YOU Profound Simple Plasma Focus