1. Overview of High Pulsed Power domain and their applications
Dominique Huet - EGO
I will talk about a subject you have probably never heard before and you will probably never hear after. It is a kind of break so you can have some rest. This subject is the high pulsed power, namely HPP, domain in which I was involved before arriving here 2 months ago. Mainly it deals with electrical energy and the generation of very powerful electrical pulses

2. Principles and applications of HPP
Initial Storage
~min
Marx generator
Inductive Voltage Adder
Water lines
Éclateurs
Capacitive storage
Vacuum lines
Plasma Opening Switch
Inductive storage
Pulse forming section
~µs
Load
~100ns
Z-pinch
Short circuit
Diode
Electron Beam
High Pressures
Radiation
High temperatures
I describe now the way such type of machines works.
First the energy is stored in capacitors with typical voltage between 50kV and 100kV. The charging time is of the order of the minute and the energy stored in a capacitor is around tens of kJ.
Then, by the use of appropriate switches this energy is delivered to pulse forming section in a characteristic time of the order of the μs.
And then this energy is delivered to load in around 100ns. Actually it is the load that fixes the characteristic rise time of 100ns. The experience has showed that the load works better with a short energy pulse than with a longer one.
The generators are mainly of two types : the Marx generator and the IVA.
Depending on the form the energy is transferred we have two types of machines :
If it is mainly under the form of voltage pulse we speak about capacitive storages and the most common elements used are water line and high voltage switches.
if it is mainly under the form of a current pulse we speak about inductive storage and the most common elements used are vacuum line and plasma opening switches.
The loads can be of three types :
- An open circuit or diode. In this case you generate an electron beam that impinges a target and produces breamstralhung in the range 100keV till 1Mev. It is used to study materials under such radiation or to radiography very dense object.
A short circuit and then you obtain very high pressure in the Mbar range. It is useful for the Equation of State studies.
A z-pinch and in this case you can have radiation in the soft X-ray range (500eV-10keV) that you can use directly or to heat a cavity (holeraum)

3. Generators and Z-pinch
2MA, 800ns
505kJ à 80kV
Ø=5m, h=7m
4MA, 1µs
1120kJ à 50kV
Ø=18m, h=3m
Ø wires: 10 to 50µm
Rpinch: cm
hpinch: cm

4. Diffusion equation in the framework of the MHD
The POS
Cathode
Anode
CONDUCTION PHASE
Plasma
Plasma Guns
OPENING PHASE
Load
Amplifier
Generator
Diffusion equation in the framework of the MHD
The diffusion term installs a precursor field from which the 2 others effects can exist
Problem when it happens on lengths smaller than those defining the validity of the MHD