introduction to pulsed power - seoul national...

High-voltage Pulsed Power Engineering, Fall 2018

Introduction to Pulsed Power

Fall, 2018

Kyoung-Jae Chung

Department of Nuclear Engineering

Seoul National University

2/30 High-voltage Pulsed Power Engineering, Fall 2018

Introduction

Pulsed power technology is an area of interest to physicists and engineers in fields requiring high voltages and large currents.

Modern pulsed power runs the gamut from its historical roots in flash radiography, X-ray generation, and the simulation of weapons effects, such as nuclear electromagnetic pulse (EMP), to packaged pulsed power for directed energy weapons and biological and medical applications. New applications and techniques continue to emerge.

References

J. Lehr and P. Ron, Foundations of Pulsed Power Technology, IEEE Press (2017). P. W. Smith, Transient Electronics: Pulsed Circuit Technology, John Wiley and Sons

(2002). H. Bluhm, Pulsed Power Systems: Principles and Applications, Springer (2006). S. T. Pai and Qi Zhang, Introduction to High Power Pulse Technology, World Scientific

(1995). G. A. Mesyats, Pulsed Power, Springer (2005). F. T. Ulaby and U. Ravaioli, Fundamentals of Applied Electromagnetics, Pearson

(2015).


Plasma: energy compression in space

Heat / Energy

Generation of spatial region where energy state is higher than surroundings (tokamak, processing chamber, plasma jet)

Generation of energetic particles, chemically active species

Energy confinement (compression) in space


Pulsed power: energy compression in time

Pulsed Power Technology: the storage of electrical energyover a relatively long time scale and its release in a shortduration to create very high power level

Example: E = 1 kW x 1 sec = 1 kJP = 1 kJ / 1 us = 1 GW


Features of pulsed power

High Power (大電力) Short rise time

Short pulse width

Focusing of high power in a narrow space

Generation of high voltage and current

New application of electromagnetic energy

Pulsed power is a scheme where stored energy is discharged as electrical energy into a load in a single short pulse or as short pulses with a controllable repetition rate.


Features of pulsed power

Pulsed power is a special power conditioning technique that transforms the characteristics of the prime energy source to the electrical requirements of the load.

Energy from a primary source is accumulated over a relatively long time scale and compressed into pulses of high instantaneous power.

Several stages may be needed to fully exploit the time dependence of breakdown of insulating materials to deliver energy with the required time dependence and amplitude for the application.

The resulting peak power delivered to the load has a large ratio of instantaneous-to-average power.


Pulse shape parameters


Typical waveform of repetitive pulses

𝐷𝐷(𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑) =𝑇𝑇𝑜𝑜𝑜𝑜

𝑇𝑇𝑜𝑜𝑜𝑜 + 𝑇𝑇𝑜𝑜𝑜𝑜𝑜𝑜


RF pulse


Generation of high power pulses


Typical pulsed power systems

Capacitive

Inductive


Applications of pulsed power

High Energy Density Plasma Nuclear fusion plasma, X-ray generation, Pinch plasma

High Power Pulse Laser Solid state laser (Nd:YAG), Gas laser (Excimer, CO2, Nitrogen)

Particle Beam Generation & Application

Electron (Ion) acceleration, Material processing, Surface treatment

Electromagnetic Acceleration Rail gun (EM gun), Electrothermal chemical gun (ETC gun),

Electromagnetic Forming

Electromagnetic Wave Generation High power microwave (HPM), Electromagnetic pulse (EMP)


Applications of pulsed power

Industrial applications Metal shaping (complex geometries)

Nano-sized particle fabrication

Rock blasting (at construction site)

Exhaust gas treatment

Thermal power plant (electric dust collector)

Waste water treatment (organic matter decomposition)

Ballast water treatment


Examples of pulsed power

Lightning vs Pikachu

http://en.wikipedia.org/wiki/File:Lightning_striking_the_Eiffel_Tower_-_NOAA.jpg

http://en.wikipedia.org/wiki/File:Lightning_striking_the_Eiffel_Tower_-_NOAA.jpg



High energy density plasmas (HEDP)

Plasma focusMIF

Pulsed IECSpheromak formation

Plasma thruster

Z-pinch plasma



Z machine (SNL) : X-ray generator

The Z Pulsed Power Facility, informally known as the Z machine, is the largest high frequency electromagnetic wave generator in the world and is designed to test materials in conditions of extreme temperature and pressure. Since its refurbishment in October 1996, it has been used primarily as an inertial confinement fusion (ICF) research facility.



WDM (Warm dense matter) or HEDP research

Warm dense matter research using wire explosion

Electrical conductivity and wire temperature measurements

K. J. Chung et al., J. Appl. Phys. 120, 203301 (2016)

Intense X-ray generation by pulsed X-pinch

𝜎𝜎 = 𝜎𝜎(𝜌𝜌,𝑇𝑇)

Wide-range EOS model Exp. vs model

Shadowgraphy image of exploding wire



Pulsed ion beam pulsed D-D beam-target fusion neutron source

Pulsed D-D neutron source (104 neutrons / 10 us)

Compact, sealed-type D-D neutron generator

8x104 n/pulse

• 150 keV, 500 mA pulsed D+ beam

Sealed-off

• Process for metal-hydride reservoir & target

Ion source

D2 gas reservoir (Zr powder) TiD2 target

D+

Ion source D+ TiD2 target

0 10 20 30 40 50 60

-100

-80

-60

-40

-20

0 Vc = 3.6kV

Outp

ut p

ulse

[kV]

Time [µs]



Beam-plasma target fusion proton source

3He gas

MW (2.45 GHz)

Al foil

Proton (14.7 MeV)

D0 beamPump

D + 3He p + 4He

D2 gas

RF (13.56 MHz)

NeutralizerAccelerator

Ion source

Magnetic Mirror Coil

Plasma

Whole-body PET scan using 18F-FDG

p + 18O n + 18F

If we increase the electron temperature of target plasma by mirror-confinement,the slowing down time of the injected particle is greatly increased, increasingbeam-target interaction probability.

Neutron production is possible if D2 gas is used as a target. BNCT



Fusion (MCF vs. ICF)



VEST

Partial Solenoid

Partial Solenoid

VacuumChamber

TF Coils

Breakdown by Partial Solenoid

Breakdown by Partial Solenoid

Plasma Merging



Laser fusion

NIF aims to create a single 500 terawatt (TW) flash of light that reaches the target from numerous directions at the same time, within a few picoseconds. The design uses 192 individual "beamlets", which are amplified in 48 beamlines containing 16 laser amplifiers per line, each one amplifying four of the beamlets.

Laser

Target chamber



Railgun

http://en.wikipedia.org/wiki/File:Railgun_usnavy_2008.jpg

http://en.wikipedia.org/wiki/File:Railgun_usnavy_2008.jpg



Coilgun

A coilgun is a type of projectile accelerator that consists of one or more coils used as electromagnets in the configuration of a synchronous linear motor which accelerate a magnetic projectile to high velocity.



ETC (Electro-thermal Chemical) gun



High Power Microwave or EMP



EM forming



EM blasting

o.o3 m3 concrete block



Underwater shockwave generation

처리 전 처리 후

정경재외, 대한지질공학회지 23, 29 (2013)K. J. Chung et al., Contrib. Plasma Phys. 53, 330 (2013)K. J. Chung et al., Curr. Appl. Phys. 15, 977 (2015)S. G. Lee et al., J. Korean Phys. Soc. 66, 1845 (2015)K. Lee et al., J. Appl. Phys. 121, 243302 (2017)K. Lee et al., Appl. Phys. Lett. 112, 134101 (2018)

기술 상용화(지하수 관정 세정 기술)

10kV/5mm

수중 초음파 발생기

슬러지 처리

지하수 관정 세정

녹조 제거

지반 강화

암반 파쇄



Water-bloom removal

w/o pulse w/ pulse

w/o pulse w/ pulse

Gas vesicles

NOx removal 40 kV, 4 MW, 0.15 J/pulse, 100 Hz 20% reduction of NOx with 15 W

Shock wave destroys gas vesicles to sink the water-bloom down to the bottom

introduction to pulsed power - seoul national...

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